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BULLETIN DU MUSEUM NATIONAL D'HISTOIRE NATURELLE

4 e série, 14 , 1992, section A (Zoologie, Biologie et Écologie animales), n° 2

SOMMAIRE — CONTENTS

J. Healy. — Dimorphic spermatozoa of the hydrothermal vent prosobranch Alvini-

concha hessleri : systematic importance and comparison with other caenogastro-

pods . 273

Le dimorphisme des spermatozoïdes du Prosohranche des sources hydrothermales Alvinicon-

cha hessleri : importance systématique et comparaison avec les autres caenogastrapodes.

P. G. Oliver and R. von Cosel. — Taxonomy of Tropical West African Bivalves. IV.

Arcidae. 293

Étude taxonomique de Bivalves de l’Afrique de l’Ouest. IV. Arcidae.

C. E. Prieto y A. I. Puente. — El género Hygromia Risso, 1826 en la Peninsula

Ibérica, con descripciôn de Hygromia gofasi sp. nov., y consideraciones sobre

la interpretaciôn funcianal del aparato estimulador de Hyggomiidae. 383

The genus Hygromia Risso, 1826 in the Iberian Peninsula, with description of Hygromia

gofasi sp. nov., and considerations on the functional interpretation of the stimmulatory

apparatus of Hygromiidae.

C. De Ridder, B. David and A. Larrain. — Antarctic and Subantarctic echinoids

from ‘Marion Dufresne’ expeditions MD03, MD04, MD08 and from the

‘ Polarstern ’ expedition Epos III. 405

Ëchinides antarctiques et subantarctiques des expéditions « Marion Dufresne » MD03, MD04,

MD08 et «Polarstern» Epos III.

J.-P. Lechapt. — Neovermilia anoperculata, nouvelle espèce bathyale de Nouvelle-

Calédonie (Polychaeta, Serpulidae). 443

Neovermilia anoperculata, new deep water species from New Caledonia (Polychaeta, Ser¬

pulidae ).

N. Gourbault et M. Vincx. — Neotonchinae de la baie de Morlaix (Nematoda,

Chromadorida). 449

Neotonchinae from the bay of Morlaix (Nematoda, Chromadorida).

A. Pedroli-Christen et J. -P. Mauriès. — Un genre oublié d'Atractosomatinae

des Alpes italo-suisses, Bomogona Cook, 1895 : statut, contenu, chorologie

(Diplopoda, Craspedosomatida).

A neglected genus of Atractosomatinae from Italian and Swiss Alps, Bomogona Cook, 1895 :

status, content, chorology (Diplopoda, Craspedosomatida).

W. R. Lourenço. — Biogéographie des espèces du groupe naturel « Tityus cla-

thratus » (Chelicerata, Scorpiones, Buthidae).

Biogeography of the natural group of species ‘ Tityus clathratus ’ (Chelicerata, Scorpio-

piones, Buthidae).

J. Forest. — Présence du genre Bathynarius (Crustacea, Decapoda, Diogenidae) en

Indonésie et dans le Pacifique central, avec la description de deux espèces nou¬

velles .

Presence of the genus Bathynarius (Crustacea, Decapoda, Diogenidae) in Indonesia and

Central Pacific, with the description of two new species.

P. J. F. Davie. — Deepwater Xanthid crabs from French Polynesia (Crustacea,

Decapoda, Xanthoidea) .

Les crabes xanthides des eaux profondes récoltés en Polynésie française ( Crustacea. Deca¬

poda, Xanthoidea).

Bull . Mus . natl . Hist , nat ., Paris, 4' sér., 14 , 1992,

section A, n° 2 : 273-291.

Dimorphic spermatozoa

of the hydrothermal vent prosobranch Alviniconcha hessleri :

systematic importance and comparison with other caenogastropods

by John Healy

Abstract. Ultrastructural features of euspermatozoa and paraspermatozoa of Alviniconcha

hessleri Okutani & Ohta are described and compared with available data for other gastropods.

Euspermatozoa are filiform, 130-135 p.m long, with a conical acrosomal vesicle (featuring an apical bleb),

a curved, rod-shaped nucleus, an elongate midpiece (with 10-11 helically coiled mitochondrial elements),

an annular complex, a glycogen piece and an end piece. An unusual sheath of dense material of uncertain

origin is associated with the nucleus and the midpiece. Apart from this sheath, most other features of

Alviniconcha euspermatozoa occur in euspermatozoa of the Neotaenioglossa (in particular groups such as

the Loxonematoidea (Abyssochrysidae), Vermetoidea, Calyptraeoidea, Littorinoidea, Truncatelloidea)

and certain Neogastropoda. Paraspermatozoa of Alviniconcha consist of large, moderately electron-dense

vesicles, smaller, highly electron-dense bodies and occasional mitochondria all enclosed by the plasma

membrane. These cells lack axonemes, recognizable nuclear material and an acrosome. Although similar

‘nurse cell’ type paraspermatozoa associate with euspermatozoa to form spermatozeugmata in the

Littorinoidea and Abyssochrysidae, this phenomenon was not observed in Alviniconcha. Sperm

ultrastructure indicates that Alviniconcha belongs within the Neotaenioglossa and is more closely allied to

the Littorinoidea-Loxonematoidea than to the Calyptraeoidea or Hipponicoidea. Specifically, sperm data

do not support a close relationship between Alviniconcha and the Architaenioglossa, the Cerithioidea or

the Trichotropidae, but are consistent with a recent proposal to include the genus within the

loxonematoidean family Provannidae.

Résumé. — Les caractéristiques ultrastructurales des euspermatozoïdes et paraspermatozoïdes

d 'Alviniconcha hessleri Okutani & Ohta sont décrites et comparées à celles d’autres gastéropodes. Les

euspermatozoïdes sont filiformes, et mesurent 130 à 135pm de long; ils ont une vésicule acrosomiale

conique (avec bulle apicale), un noyau en forme de bâtonnet recourbé, une pièce intermédiaire allongée

(avec 10-11 éléments mitochondriaux enroulés en hélice), un complexe annulaire, une pièce à glycogène et

une pièce terminale. On observe également un manchon inhabituel de matériel dense, d’origine inconnue,

associé au noyau et à la pièce intermédiaire. A l’exception de ce manchon, la plupart des caractéristiques

des euspermatozoïdes d 'Alviniconcha se rencontrent également chez les euspermatozoïdes des Neotaenio¬

glossa — en particulier des groupes comme les Loxonematoidea (Abyssochrysidae), Vermetoidea,

Calyptraeoidea, Littorinoidea, Truncatelloidea et des Neogastropoda. Les paraspermatozoïdes

d'Alviniconcha consistent en un ensemble de grandes vésicules, modérément denses aux électrons, des

corps plus petits, très denses aux électrons, et quelques mitochondries, le tout enfermé par la membrane

plasmique. Ces cellules n’ont ni axonème, ni matériel nucléaire reconnaissable, ni acrosome. Chez les

Littorinoidea et les Abyssochrysidae, de tels paraspermatozoïdes de type « cellules nourricières »

s’associent aux euspermatozoïdes pour former des spermatozeugmata : un tel phénomène n’a pas été

observé chez Alviniconcha. L’ultrastructure des spermatozoïdes montre qu’ Alviniconcha appartient aux

Neotaenioglossa et qu’il est plus proche de la lignée Littorinoidea-Loxonematoidea que des Calyptraeoi¬

dea ou des Hipponicoidea. Dans tous les cas, ces données démentent l’idée d’une relation proche entre

Alviniconcha et les Architaenioglossa, les Cerithioidea ou les Trichotropidae, mais appuient au contraire

la proposition récente de classer ce genre dans la famille Provannidae (Loxonematoidea).

J. M. Healy, Department of Zoology , University of Queensland , 4072 Queensland , Australia .

Introduction

Exploration of deep sea hydrothermal vents continues to reveal an interesting and

taxonomically significant array of prosobranch gastropods (Fretter, 1988 ; Lutz et al., 1986 ;

McLean, 1981, 1988a-c, 1989; Warén & Bouchet, 1986, 1989). Although the majority of

these species are ‘ archaeogastropods ’ sensu lato (for example see Hickman, 1984 ; McLean &

Haszprunar, 1987; McLean 1988a-h, 1989) a number of unusual caenogastropods have also

emerged from the vent communities (Warén & Bouchet, 1986; Warén & Ponder, 1991;

Bouchet & Warén, 1991). In describing Alviniconcha hessleri from vents in the Mariana Back-

Arc Basin. Okutani & Ohta (1988) expressed uncertainty as to the true systematic position of

their new species and genus. Shell features and the presence of well developed periostracal

hairs suggested affinities with the Trichotropidae (Calyptraeoidea), while radular shape and

formula indicated a possible connection with the Hipponicoidea (see Okutani & Ohta, 1988).

Most recently Bouchet & Warén (1991) have placed Alviniconcha and Ifremeria into the

Provannidae, a family established by Warén & Ponder (1991) for another hydrothermal vent

genus Provanna. Warén & Ponder (1991) tentatively assigned the Provannidae to the

Loxonematoidea to join another family of this relict group, the Abyssochrysidae (see

Houbrick, 1979). On the basis of comparative anatomy Bouchet & Warén (1991) concluded

that any shell similarities between the Provannidae and the Vivipariidae or Trichotropidae

were of a superficial nature only. Beck (1991) has, in contrast, suggested that Olgaconcha (a

synonym of Ifremeria Bouchet & Warén, 1991 *) and Alviniconcha may be closely related to the

Architaenioglossa (eg Vivipariidae) or the Cerithioidea.

Previous studies have shown that sperm morphology in the Mollusca reflects not only the

environment of fertilization (eg Franzén, 1955) but also the systematic position of taxa from

the level of species upwards (Popham, 1979; Kohnert & Storch, 1984; Healy, 1982, 1983a,

1986a, b, 1988a, b, 1990a-c; Koike, 1985 ; Hodgson & Bernard. 1988 ; Hodgson et al. , 1988).

In particular, within the prosobranch order Caenogastropoda (= Mesogastropoda + Neo¬

gastropoda), a reasonably good data base now exists with which to test views on the likely

position of newly discovered taxa such as Alviniconcha.

During the course of the present study it became obvious that sperm ultrastructural data

for the Trichotropidae would be needed for comparison with Alviniconcha. I have therefore

included herein a brief description and salient micrographs of the euspermatozoa and

paraspermatozoa of a representative trichotropid, Trichosirius inornatus (Suter) from New

Zealand. It is hoped that this study may stimulate further ultrastructural work on sperm

morphology of hydrothermal vent molluscs.

Materials and methods

Live Alviniconcha hessleri Okutani & Ohta, 1988 were collected during the BIOLAU

cruise of the Lau Basin, south-east of Fiji, using the submersible craft ‘Nautile’ (12-27 May,

1. Dr. P. Bouchet advises (in litt.) that Olgaconcha tufari Beck, 1991 is a synonym of Ifremeria naulilei Bouchet &

Warén, 1991. The paper by Bouchet & Warén (1991) was published before that of Beck (1991), hence the name

Ifremeria nautilei Bouchet & Warén must take priority over Olgoconcha tufari Beck.

275 -

1989). Collection data for this material are as follows : dive 12 on site Vailili, Valufa Ridge,

Lau Basin, 23°13'S, 176°38' W at a depth of 1,750 m (Observer for this dive was P. Crassous,

IFREMER, Brest). The material examined herein consists of sperm-filled, sac-like outpockets

of the distal end of the sperm duct (as described by Warén & Bouchet, 1992). Voucher

specimens of Alviniconcha hessleri have been deposited in the Muséum national d’Histoire

naturelle (Paris). Tissues were fixed in cold (0-4° C) cacodylate-buffered glutaraldehyde then

dispatched to the author for subsequent processing and analysis. Small pieces of the sperm

sacs were taken from the samples provided and processed for transmission electr m

microscopy (TEM) according to the following schedule : (1) rinse in cold 0.1 M cacodylate

buffer containing 10% sucrose (1 hr); (2) osmication of tissues for two hours (1 % osmium

tetroxide in cacodylate or phosphate buffer) ; (3) buffer rinse ; (4) gradual dehydration using

ethanol; (5) embedding in Spurr’s epoxy resin. For comparison with Alviniconcha hessleri,

portions of the sperm duct of a representative trichotropid, Trichosirius inornatus (Suter), were

processed for TEM. This material derives from sea water formalin-fixed specimens collected by

W. F. Ponder (June 1966). After rinsing in phosphate buffer, tissue pieces of Trichosirius

inornatus were processed as outlined above for Alviniconcha hessleri. All ultrathin and semithin

sections were prepared with an LKB IV Ultrotome. Ultrathin sections were stained using

Daddow’s (1986) modified double lead procedure and examined with a Hitachi 300 TEM

operated at 75kV. Tissue squashes were also examined by standard phase-contrast as well as

Nomarski-phase contrast light microscopy using an Olympus BH2 light microscope.

RESULTS

Euspermatozoa

Euspermatozoa of Alviniconcha hessleri (hereafter referred to as Alviniconcha ) are filiform,

approximately 130-135 (i.m long and comprise an acrosomal complex, nucleus, midpiece,

annular complex, glycogen piece and end piece.

Acrosomal complex : The acrosomal vesicle is conical, 0.9 p.m long and posteriorly circular

in transverse profile (pi. I C-F). It rests on a thin, basal plate which is grooved to fit the

nuclear apex (pi. I E, F). An accessory membrane attached to the basal plate sheaths the

posterior 0.5 p.m of the acrosomal vesicle (pi. I D-F). Anteriorly the vesicle membrane expands

away from the vesicle contents to form an electron lucent space : the apical bleb (pi. I B, E, F).

Oblique transverse sections reveal the presence of radially arranged plates within the matrix of

the acrosomal vesicle (pi. I D). A basal invagination, extending almost to the apex of the

vesicle, contains subacrosomal material organized as an axial rod embedded in a granular

matrix (pi. I C-F).

Nucleus : TEM confirms light microscopic observations that the euspermatozoan nucleus

of Alviniconcha is slightly curved (pi. I A). The nucleus is cylindrical (diameter 0.4pm

posteriorly, tapering to 0.2 jxm anteriorly) and approximately 7.5 p.m long, with narrow basal

invagination (0.76 p.m deep) which forms the attachment site for the centriolar derivative and

axoneme (pi. I A, G, H ; II A, E). An extensive, irregularly shaped sheath of finely granular

- 276

material is associated with the surface of the nucleus, particularly in the middle to basal

regions where nuclear contents sometimes appear fibrous in substructure (pi. I G-J ; II A).

Although ‘ ballooning ' of the plasma membrane away from the surface of the nucleus (pi. I A,

I, pi. II A) could prove to be an artifact of fixation, the localization of this phenomenon, and

the generally good preservation of other cell components tend to argue against this. As plate I

and plate II show, the dense sheath penetrates into the anterior region of the midpiece where it

partially surrounds the axoneme, and frequently the mitochondrial elements themselves. The

absence of developing euspermatozoa prevents any resolution of the origin or purpose of the

sheath substance. The varied shape and thickness of the sheath suggests either that this

structure is genuinely variable in its morphology or that it may not have reached its final form

(i.e. the observed euspermatozoa are still in the process of maturation).

Midpiece : The midpiece exhibits ten to eleven mitochondrial elements which wind

helically around a 9 + 2 pattern anoxeme (pi. I G, H, K; II C-F). Each element has flattened

adjoining surfaces and contains scattered, poorly developed cristae (pi. II C-F). As previously

mentioned the dense sheath observed in the nuclear region also occurs within the midpiece and

the nucleus-midpiece junction (pi. I G, H, K ; II E, D). Longitudinal sections through the

anterior portion of the midpiece show that the sheath surrounding the midpiece elements or

the axoneme is often discontinuous suggesting segmentation (pi. I G, H ; II D). In some

euspermatozoa, sheath material associated with the axoneme appeared to be helically arranged

(see pi. II F). The midpiece measures between 76 and 80 g.m in length (light microscopic

observations).

Annular complex, glycogen piece, end piece : The annular complex occurs at the junction of

midpiece and glycogen piece. It comprises a dense ring or ‘annulus’ (applied to the inner

surface of the plasma membrane) and a closely associated collar of dense material which lines

the terminal 0.4 fxm of the mitochondrial membrane (pi. Ill A). Within the glycogen piece each

of the nine axonemal doublets is associated with a tract of dense, putative glycogen granules

(pi. Ill A, B). As plate III C shows, the glycogen piece ends abruptly, leaving the end piece of

the euspermatozoon to consist solely of the plasma membrane and axoneme. The combined

length of the glycogen piece and end piece varies from 46 to 50 [xm (light microscopic

observations).

Paraspermatozoa

Paraspermatozoa of Alviniconcha hessleri are rounded cells containing the following

features : (1) a variable number (5-8) of large, membrane-bound, spherical vesicles; (2) one to

three spherical, highly electron dense bodies, (3) a finely granular, background matrix (4) a

delimiting, plasma membrane (pi. Ill D, E). Mitochondria were only rarely observed. No

evidence of an acrosome, axonemes (either contained within the parasperm body or emergent

as tails) or centrioles could be found. In spite of the absence of developing paraspermatozoa in

material studied, comparison with other caenogastropods suggests that the larger vesicles are

probably products of Golgi and/or endoplasmic reticular activity. The origin of the smaller,

more highly electron-dense bodies (pi. Ill D, E) is more difficult to determine. There remains

the possibility that these bodies are condensed nuclear remnants (caryomerites’ of authors) but

— 277 -

the absence of a double nuclear membrane around the bodies or any evidence of

fibrillar/coarse granular substructure or lacunae argue against this view. Wherever the large

vesicles touch, their surfaces are flattened (pi. Ill D). Undoubtedly this affords efficient

packing of vesicles and a certain degree of structural integrity for the paraspermatozoon as a

whole. Paraspermatozoa and euspermatozoa of Alviniconcha hessleri were never observed in

contact with each other, suggesting that spermatozeugmata are probably not formed in this

species.

Trichotropidae

(Trichosirius inornata Suter)

Euspermatozoa

Acrosomal complex : The acrosomal vesicle is conical and deeply invaginated with a

prominent apical bleb (pi. IV A). It has a maximum diameter of 0.3 pm near the base, and

average length of 1.0 p.m. Apically the vesicle is sometimes curved or slightly hooked,

suggesting that this organelle is flexible. A rod-shaped deposit of subacrosomal material runs

almost the full length of the vesicle invagination (0.67-0.7 pm). A thin, centrally perforate,

basal plate lies between the basal rim of the acrosomal vesicle and the nuclear apex. Although

longitudinal sections suggest the presence of an accessory membrane, the precise extent of this

feature could not be determined.

Nucleus : The euspermatozoon nucleus is elongate (approximately 50-54 pm long, light

microscopic observations), tubular and encloses the centriolar derivative and anterior portion

of the axoneme (pi. IV A-C, F). Nuclear contents are highly electron dense and decrease in

extent anteriorly until only a thin layer (0.02 pm thick) surrounds the centriolar derivative

(pi. IV A, C, F). Nine microtubular elements embedded in dense material constitute the

centriolar derivative, however the exact substructure of these elements was not determined.

The axoneme appears to show the typical 9+2 configuration. Diameter of the nucleus,

including the nuclear and plasma membranes and enclosed axoneme decreases from 0.56 pm

posteriorly to 0.33 pm near the acrosome.

Midpiece : The midpiece begins immediately posterior to the nucleus and comprises the

axoneme (continuing from the nuclear region) surrounded by five to six helically coiled,

mitochondrial elements (pi. IV B, D, E, G). Each of the mitochondrial elements exhibits

random, unmodified cristae (pi. IV D, E). The midpiece measures approximately 12 pm (light

microscopic observations).

Annular complex, glycogen piece : Longitudinal or oblique longitudinal sections revealed

that an annular complex is present at the junction of the midpiece and glycogen piece. This

complex consists of two distinct rings, each connected to the inner surface of the plasma

membrane and each showing a triangular profile in longitudinal section (pi. IV E). The

glycogen piece is recognized by the nine spoke-like structures connecting the doublets with the

plasma membrane (pi. IV G). Although transverse sections were obtained showing evidence of

periaxonemal granules attached to the spokes most euspermatozoa seemed to lack such

278 —

deposits. This is almost certainly due to the fixation deficiencies of the formalin preserved

material available for study. The numerous individual axonemes observed (all associated with

disrupted plasma membranes) are here interpreted as the terminal or end piece of the

euspermatozoon. Light microscopy gives a length of \2\im for the glycogen piece and end

piece combined.

Paraspermatozoa

Paraspermatozoa of Trichosirius inornatus are vermiform cells, 24 to 32 jxm long (light

microscopic observations) which are composed of longitudinally aligned axonemes, scattered

mitochondria, numerous oblong, dense vesicles and a granular cytoplasm (pi. IV F, G).

Transverse sections show that mature cells are laterally compressed, but moreso anteriorly

where mitochondria are positioned between the axnemes (pi. IV F). All parasperm organelles

are contained within a common plasma membrane. Axonemes are positioned peripherally,

close to or in contact with the inside surface of the plasma membrane. Towards the posterior

region of the cell, the axonemes project into shallow outpockets of the plasma membrane

(pi. IV F, G). No evidence of physical contact between paraspermatozoa and euspermatozoa

(eg spermatozeugmata formation) was observed in Trichosirius inornatus.

DISCUSSION

Structural comparison

The presence of paraspermatozoa and more importantly the morphology of the

euspermatozoa clearly identifies Alviniconcha as a caenogastropod. Caenogastropods can be

divided into two main groups on the basis of euspermatozoan features, notably the

substructure of the acrosome and midpiece (Healy, 1988a). These groups are : (1) the

Cerithioidea, Ampullarioidea and Cyclophoroidea and (2) the remainder of the Caenogastro-

poda. The first of these groups is characterized by absence of an apical bleb and accessory

membrane in the acrosomal complex and presence of highly organized, parallel cristal plates in

the mitochondrial elements. Alviniconcha belongs to the second, larger group of caenogastro¬

pods, the euspermatozoa of which possess an apical bleb (sometimes poorly developed), an

accessory membrane (also present in the enigmatic bridging group Campaniloidea — see

Healy, 19866), and 5 to 11 helically coiled mitochondrial elements (cristae usually unmodified,

sometimes tubular). In all caenogastropod euspermatozoa with the exception of the

truncatelloidean Stenothyra sp. (Healy, 19836), the glycogen piece exhibits nine periaxonemal

tracts of granules. Elsewhere within the Mollusca this arrangement of sperm glycogen deposits

occurs in the Octopoda (Longo & Anderson, 1970).

Euspermatozoa of Alviniconcha differ from those of other caenogastropods in possessing

a well developed sheath of electron dense material which extends from the nucleus into the

anterior portion of the midpiece. An absence of spermiogenic stages in material available for

— 279 -

study prevented any determination of the origin of this dense sheath. The frequently observed

‘ disjointed ’ nature of the sheath within the Alviniconcha midpiece invites comparison with the

segmented midpiece sheath observed in euspermatozoa of the relict campaniloidean Campanile

symbolicum Iredale (see Healy, 1986/?). Although the origin of the Campanile sheath is also

unknown, it is, in contrast to the Alviniconcha sheath, composed of equal-sized elements which

are membrane bound and never associated with the nucleus. In Alviniconcha the dense sheath

is well developed in the region of the nucleus (actually contacting the nuclear surface), while

posteriorly, it often extends around the axoneme and midpiece elements. Spermatozoa of

certain stylommatophoran pulmonates also possess a non-membrane bound perinuclear

sheath which may be layered (eg Helix aspersa (Müller); Healy & Jamieson, 1989) or exhibit

paracrystalline substructure (eg Oxyloma elegans (Risso); Selmi et al., 1989). In Oxyloma

elegans, the sheath disappears during storage in the seminal receptacle (Selmi et al., 1989).

Unlike Alviniconcha, the sheath in pulmonate sperm does not also extend into the midpiece.

The marked variation in thickness and distribution of the dense sheath in Alviniconcha

suggests that this structure perhaps has not attained its final form (? a late spermiogenic

feature) or alternatively, is genuinely variable in its morphology. Detailed study of spermatids

and seminal receptacle spermatozoa will help determine the origin and possible function of the

sheath material. Even if the observed sheath is not fully mature in its form or proves to be a

transient feature, its presence distinguishes Alviniconcha from other caenogastropods. I will

return to the possible taxonomic implications of Alviniconcha eusperm morphology in the final

section of this discussion.

Paraspermatozoa of Alviniconcha closely resemble those of the Littorinoidea (especially

Littorina, see Buckland-Nicks & Chia, 1977) and the loxonematoidean Abyssochrysos

brasilianum Bouchet (see Healy, 1990a). In paraspermatozoa of all three taxa, an acrosome,

axonemes and centrioles are absent, and large secretory vesicles suspended within a granular

matrix constitute the bulk of the spherical cell body. In Abyssochrysos, the littorinid subfamily

Littorininae and the atlantoidean Carinaria lamarcki Péron & Lesueur, euspermatozoa attach

in an organized cluster to each paraspermatozoon to form spermatozeugmata (Reinke, 1912;

Buckland-Nicks & Chia, 1977 ; Thiriot-Quievreux & Martoja, 1979 ; Kohnert & Storch,

1984; Reid, 1986; Healy, 1990a). Spermatozeugmata were not observed in Alviniconcha but

this is also the case in certain littorinids which possess ‘ nurse cell ’ type paraspermatozoa such

as the genus Peasiella (Reid, 1989) and probably the genus Provanna (Provannidae,

Loxonematoidea — see Warén & Ponder, 1991). Although the large vesicles of Alviniconcha

paraspermatozoa are probably products of Golgi and/or endoplasmic reticular activity (as

occurs in other caenogastropods), the likely origin of the highly electron-dense bodies is

problematical. Two alternatives seem possible. Either these bodies represent condensed nuclear

remnants ( = ‘ caryomerites ’) or they are another form of secretory product. Observations on

parasperm development would help to clarify this issue, but for the present it is worth noting

that the dense bodies are enclosed by a single and not a double (eg nuclear) membrane and

that the bodies show no evidence of nuclear substructure such as fibrils, coarse granules or

lacunae. Although paraspermatozoa of most littorinids and Abyssochrysos do not retain a

nuclear fragment (Buckland-Nicks & Chia, 1977; Reid, 1986; Healy, 1990a) some species

do (Reid, 1986). Retention of condensed nuclear material in caenogastropod paraspermatozoa

is not unusual for certain taxa (eg Cyclophoroidea, Cerithioidea ; Selmi & Giusti, 1980;

Healy, 1986a, 1988a).

— 280 -

Systematic implications

The systematic position of Alviniconcha was briefly discussed by Okutani & Ohta (1988)

in their account of the new species and genus. They suggested a possible link between

Alviniconcha and the calyptraeoidean family Trichotropidae (conchological features including

prominent ‘hairy’ periostracum) or, in view of radular features perhaps a closer connection

between the genus and the Hipponicoidea 1 . Beck (1991) believes that Alviniconcha and

Olgaconcha (a synonym of Ifremeria Bouchet & Warén, 1991 ; see footnot 1, p.274) may be

closely related to the Architaenioglossa (Vivipariidae and allies) or the Cerithioidea. A

stronger case, favouring loxonematoidean affinities for Alviniconcha has been put forward by

Warén & Bouchet (1992).

Comparative sperm data for the Caenogastropoda, despite being fragmentary for the

Calyptraeoidea and Hipponicoidea, provide some basis for evaluating these differing views

concerning the relationships and systematic position of Alviniconcha. To begin with, let us

consider the possibility of a Calyptraeoidea or Hipponicoidea connection. Some genera of the

Calyptraeoidea (for example Calyptraea, Crepidula) possess a short eusperm nucleus

(Kohnert & Storch, 1984) like Alviniconcha , while in other genera such as Trichosirius (this

study) and the Hipponicoidea ( Vanikoro ; Healy, 1984) it is long and tubular. The value of

eusperm nuclear shape in the Caenogastropoda is limited, for in some families (eg Littorinidae,

Turridae, Eulimidae, Terebridae) different genera may show short or tubular nuclei (although

the shape appears consistent in any given genus) (Healy, 1984, 1988a; Kohnert & Storch,

1984; Koike, 1985). Other euspermatozoan features such as the acrosomal complex, midpiece

and glycogen piece of Alviniconcha are similar to those seen in the Calyptraeoidea,

Hipponicioidea and in fact many other caenogastropod superfamilies (Bulnheim, 1962;

Healy, 1984, 1988a, b, 19906; Kohnert & Storch, 1984; Koike, 1985). The dense sheath of

Alviniconcha euspermatozoa is not, however, seen in any other group (the segmented sheath of

Campanile being here regarded as non-homologous). More significantly perhaps than eusperm

morphology, the paraspermatozoa of the Calyptraeoidea ( Crepidula , Gould, 1917; Trichosi¬

rius , this study) are vermiform cells with multiple, internal axonemes and small secretory

vesicles. This type of paraspermatozoon, also recorded in other caenogastropod groups such

as the Cypraeoidea, Dolioidea, Muricoidea (Melone et al., 1980; Healy, 1988a), contrasts

with the round paraspermatozoa of Alviniconcha which exhibit large secretory vesicles lack

axonemes. No data on the presence or structure of paraspermatozoa in the Hipponicoidea or

the Fossaridae are at present available, the latter family being transferred to the Cerithioidea

(now as subfamily of Planaxidae ; see footnote 1, p. 274). To sum up, eusperm and parasperm

structure do not provide any overwhelming support for a connection between Alviniconcha

and the Calyptraeoidea or the Hipponicoidea (specifically the Trichotropidae).

A large body of information now exists on the fine structure of euspermatozoa and

paraspermatozoa in the Architaenioglossa (Ampullarioidea, Cyclophoroidea) and the Ceri-

I. In their discussion of the relationships of Alviniconcha, Okutani & Ohta (1988) cite the Fossaridae as a member

family of the Hipponicoidea. Anatomical studies have shown that species of the genus Fossarus share a cephalic brood

pouch with the Planaxidae, and partly on this basis the Fossaridae were transferred to the Cerithioidea (Ponder, 1980;

Ponder & Warén, 1988). Houbrick (1990) has subsequently reduced the Fossaridae to the status of subfamily within

the Planaxidae.

— 281 —

thioidea (for principal references see Healy, 1983a, 1986a, 1988a; Kohnert & Storch, 1984;

Koike, 1985). These groups are united by many similarities in eusperm and parasperm

morphology, but do not share any significant similarities with either the euspermatozoa or

paraspermatozoa of Alviniconcha. On this basis I cannot support Beck's (1991) suggestion that

Alviniconcha or Olgaconcha (= Ifremeria ) may be closely related to the Architaenioglossa or

the Cerithioidea.

A further view, that of an ^/v/n/coac/ia-Loxonematoidea relationship (proposed by

Bouchet & Warén, 1991) seems much more promising than those already considered above,

primarily because the only caenogastropod known to possess similar euspermatozoa and

paraspermatozoa to Alviniconcha is Abyssochrysos brasilianum Bouchet (Abyssochrysidae,

Loxonematoidea). There are a few differences however. Unlike Alviniconcha, euspermatozoa

and paraspermatozoa of Abyssochrysos definitely form spermatozeugmata similar to those of

many Littorinidae (Healy, 1990a; see also Buckland-Nicks & Chia, 1977). Secondly, the

dense sheath of Alviniconcha euspermatozoa is lacking in Abyssochrysos. Absence of

spermatozeugmata in Alviniconcha may not be as taxonomically significant as it first appears

because the same situation has been noted in Provanna (recently transferred to Loxonematoi¬

dea) and in certain littorinids (Reid, 1989; Warén & Ponder, 1991). Eusperm nuclei of

Provanna differ from those of Alviniconcha in being elongate and tubular rather than short and

solid (Healy, 1990c).

In conclusion, sperm morphology supports a close relationship between deep-sea taxa

such as Alviniconcha, Abyssochrysos and Provanna , and other basal neotaenioglossans notably

the Littorinoidea. Bouchet & Warén (1991) have grouped Provanna, Alviniconcha and

Ifremeria within the Provannidae (of Warén & Ponder, 1991), and following Warén &

Ponder, tentatively included this family in the Loxonematoidea (to join the Abyssochrysidae).

In spite of anatomical differences, the Littorinoidea and Loxonematoidea (now including

Abyssochrysidae and Provannidae) significantly exhibit the same eusperm and parasperm

morphology. This similarity may prove to be due to symplesiomorphy, although it is by no

means certain that the ‘ nurse cell ’ paraspermatozoon of the Littorinoidea and Loxonematoi¬

dea is in fact a basal, unspecialized type relative to the axonemal paraspermatozoa of other

caenogastropods (see Jamieson, 1987 for further discussion). In other lower neotaenioglossan

superfamilies, paraspermatozoa appear to be absent in the Truncatelloidea and Cingulopsoi-

dea (Healy, 1984; but see Ponder, 1983 for the possibility of parasperm in Barleeidae) while

euspermatozoa and paraspermatozoa of the Cerithioidea and Architaenioglossa show

numerous differences from those of the Littorinoidea and Loxonematiodea (see Healy, 1983a,

1986a, 1988a for comparison and further references). Undoubtedly as knowledge of sperm

structure in basal groups within the Neotaenioglossa improves, a clearer picture of the

phytogeny of this caenogastropod assemblage will emerge.

Acknowledgements

The material of Alviniconcha hessleri used in this study was taken during the BIOLAU

cruise, under the direction of Dr. A. M. Alayse (IFREMER, Brest). 1 thank Dr. A. Fiala

(Laboratoire Arago, Banyuls) and Mr. D. Jollivet (IFREMER, Brest) for fixing tissues specifi¬

cally at the request of Dr. P. Bouchet (Muséum national d'Histoire naturelle, Paris). All work

described in this paper was conducted in the Department of Zoology, University of Queensland.

— 282

The technical assistance of Mrs L. Daddow and Mr. T. Gorringe of this Department is gratefully

acknowledged. Mr. B. A. Marshall (National Museum of New Zealand, Wellington) kindly provided

formalin preserved (collection) material of Trichosirius inornatus (Suter) for sperm ultrastructure.

The text has also benefited from comments by Dr. A. Warén (Swedish Museum of Natural History),

Dr. W. F. Ponder (Australian Museum, Sydney), Dr. P. Bouchet (Muséum national d’Histoire

naturelle) and the referee. I also thank Dr. Bouchet for his considerable efforts in securing mate¬

rial for study and also for providing a French translation of the abstract. Dr. Warén kindly

provided me with a copy of the text of his paper with Dr. Bouchet (in press) on the morphology

and relationships of new species from hydrothermal vents and carbon seeps (Warén & Bouchet,

1992). This study was supported financially by an Australian Research Fellowship of the Australian

Research Council.

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Plate 1

Alviniconcha : euspermatozoa

A — Longitudinal section (L.S.) through acrosome, nucleus and proximal portion of midpiece. Note expanded plasma

and nuclear membranes (*).

B-C — Series of transverse sections (T.S.) from apex to base of acrosomal complex. Plate substructure visible in wall of

vesicle in pi. 1 D (arrow heads).

D, E — L.S. acrosomal complex and nuclear apex of two euspermatozoa.

G, H — L.S. junction of nuclear invagination and proximal portion of midpiece. Note disjointed nature of dense

sheath associated with axoneme and mitochondrial elements.

I, J — T.S. nuclei and dense sheath.

K — T.S. junction of nucleus and midpiece.

Scale bars : A = l.Ofxm; G, H = 0.5 (j.m; B-F, K, J = 0.25 p.m

Abbreviations used in the figures : a, acrosomal complex ; ab, apical bleb ; am, accessory membrane (of acro¬

somal complex); an, annular complex; ar, axial rod (of acrosomal complex); av, acrosomal vesicle; ax, axoneme;

bp, basal plate (of acrosomal complex) ; c, centriolar derivative ; ds, dense sheath (of euspermatozoon) ; ep, end

piece; eu, euspermatozoa; gp, glycogen piece; m, unmodified mitochondrion; M, midpiece; mpe, midpiece (mito¬

chondrial) elements ; n, nucleus ; p, paraspermatozoon ; pm, plasma membrane ; v, oblong vesicles.

r Is 7^ÊSÈÊÈÊ

mmSÊF / _

<9 lisp ,ap^fe%

_ J

, Jr

8| . '-• IAA

- 286 —

Plate II

Alviniconcha : euspermatozoa

A — L.S. base of nucleus showing expanded nature of plasma and nuclear membranes (*).

B — T.S. nucleus and dense sheath.

C — T.S. midpiece. Note dense sheath associated with periaxonemal surface of mitochondrial elements.

D — L.S. proximal portion of midpiece showing dense sheath associated with mitochondrial elements and axoneme.

Inset : T.S. same region of midpiece.

E — L.S. junction of nucleus and midpiece showing seemingly ‘ fluid ’ nature of dense sheath.

F — L.S. midpiece showing slight spiralling of dense sheath around axoneme. Inset : same region of midpiece.

Scale bars : A = 0.5 pm; B-F = 0.25 p.m.

— 288 -

Plate III

Alviniconcha : euspermatozoa and paraspermatozoa

A — L.S. junction of midpiece and glycogen piece showing annular complex.

B — T.S. junction of nucleus and midpiece (upper right), midpiece and glycogen piece.

C — L.S. junction of glycogen piece and end piece.

D — Paraspermatozoa. Note large vesicles pressed against each other, and occasional, highly electron-dense bodies

(arrow). Inset showing three dense bodies within a common membrane.

E — Detail of dense body and portion of a large vesicle.

Scale bars : A-C = 0.5 pm; D-E = 1.0 pm.

290 -

Plate IV

Trichosirius inornatus : euspermatozoa and paraspermatozoa

A — L.S. through eusperm acrosomal complex and nuclear apex.

B — L.S. through eusperm nucleus-midpiece junction.

C — T.S. through eusperm nuclear apex and centriolar derivative.

D — T.S. eusperm midpiece showing 5-6 helical, mitochondrial elements.

E — L.S. junction of midpiece and glycogen piece showing annulus (2 rings) and helical mitochondrial elements.

F — T.S. eusperm nucleus (in region of centriolar derivative) and flattened anterior region of paraspermatozoon (note

interspersed axonemes and mitochondria).

G — T.S. various regions of euspermatozoa and paraspermatozoa. 1-3 indicate anterior-posterior sequence through

paraspermatozoa. Note spoke-like structures within the glycogen piece of euspermatozoa.

Scale bars : A-E = 0.25 pm ; F = 0.5 pm.

Bull. Mus. natl. Hist, nat., Paris, 4 e sér., 14 , 1992,

section A, n° 2 : 293-381.

Taxonomy of Tropical West African Bivalves

IV. Arcidae

by P. Graham Oliver and Rudo von Cosel

Abstract. — Twenty species of Arcidae are described from tropical West Africa, defined here as

between 23° N and 17° S. The Arcinae are represented by four genera and include four new taxa : Area

avellana turbatrix n. subsp., Barbatia gabonensis n. sp., B. ionthados n. sp., B. ( Nipponarca) allocostata n.

sp. The anatomy of the latter is described and confirms the value of the subgenus which is redefined. The

Anadarinae, other than Senilia and Bathyarca are all included in the genus Anadara because the use of the

ligament orientation and inequivalve condition are abandoned as phyletic characters. Two new species are

described : Anadara eborensis n. sp. and A. camerunensis n. sp. A. polii (Mayer) is the species often cited as

“A. diluvii (Lamarck)” in publications concerning the Mediterranean. Variation within species is

frequent, notably in Anadara polii and A. senegalensis. Ecological factors and geographical dines are

invoked to explain some of this variation but local genetic isolation could not be excluded. The

relationships of the shallow water West African species are analysed and compared to the faunas of the

Mediterranean, Caribbean, Panamic and Indo-Pacific regions. Only one genus is endemic to West Africa,

namely Senilia. There are three species common to the Mediterranean but none to the Caribbean

although there are sibling species. Overall similarity is greatest with the Indo-Pacific but the Anadarinae

in isolation have affinity to the Panamic fauna. A general discussion on the zoogeographical patterns for

all the Arcoidea is presented in the concluding part of this study which is to be published in the next issue

of the Bulletin du Muséum.

Résumé. — Description de vingt espèces d’Afrique occidentale tropicale, ici définie entre 23° N et

17°S. Les Arcinae sont représentés par quatre genres; quatre taxa nouveaux y sont inclus : Area avellana

turbatrix n. subsp., Barbatia gabonensis n. sp., B. ionthados n. sp., B. ( Nipponarca ) allocostata n. sp.

L’anatomie de la dernière est décrite, confirmant la valeur du sous-genre ici redéfini. Outre Senilia et

Bathyarca , toutes les Anadarinae sont incluses dans le genre Anadara , car l’utilisation de l’orientation du

ligament et l’inégalité des deux valves sont abandonnées en tant que caractères phylétiques. Deux espèces

nouvelles, Anadara eborensis n. sp. et A. camerunensis n. sp. sont décrites. Dans des publications

concernant la Méditerranée, A. polii (Mayer) a été souvent citée comme « A. diluvii (Lamarck) ». Une

variabilité intraspécifique est fréquente, surtout chez A. polii et A. senegalensis. Des facteurs écologiques

ainsi que des clines géographiques sont évoqués pour l’explication d’une partie de cette variabilité, mais

on ne peut pas exclure d’une isolation génétique locale. Les espèces du plateau continental ouest-africain

sont analysées sur le plan de leurs relations, et comparées avec les faunes de la Méditerranée, des

Caraïbes, du Pacifique panaméen et de l’Indo-Pacifique. Senilia est l’unique genre d’Arcidae endémique

de l’Afrique occidentale. Trois espèces vivent aussi en Méditerranée, mais aucune n’est présente dans les

Caraïbes bien qu’il y ait des espèces jumelles. Les Arcidae dans leur ensemble présentent le maximum de

similitude avec celles de l’Indo-Pacifique ; cependant les Anadarinae montrent une affinité plus marquée

avec celles du Pacifique panaméen. Une discussion générale sur la répartition zoogéographique de tous les

Arcoidea se trouve dans une deuxième partie de cette étude, qui sera publiée dans le prochain numéro du

Bulletin du Muséum.

P. G. Oliver, National Museum of Wales, Cardiff, U.K.

R. von Cosel, Muséum national d’Histoire naturelle. Laboratoire de Biologie des Invertébrés marins et Malaco¬

logie, 55, rue Buffon, 75005 Paris.

Introduction

This paper on the Arcidae and the forthcoming second part on the Noetiidae (which also

will contain the concluding discussion) are parts of a revision of the Bivalvia of tropical West

Africa being undertaken by the second author and made possible by the availability of recent

collections through ORSTOM (with main part of the fieldwork by the second author) and

Serge Gofas (MNHN). The region is defined here as lying between Rio de Oro (southern part

of West Sahara, 23° N) and Baia dos Tigres (Southern Angola, 17°S). Previous studies of the

region are sparse with only the work of Dautzenberg (1909, 1913, 1927) and Nicklès (1950,

1955) of note. These papers illustrate the concept of shared taxa with the Caribbean and

Mediterranean regions but the recognition of pan Atlantic species and local species appears to

be inconsistent. For example the Barbatia Candida/complanata complex was usually considered

to be a single pan Atlantic species but the equally confusing Arcopsis afra/adamsi complex (cf.

second part, Oliver and Cosel, in print) has always been regarded as two distinct species.

Interestingly A. afra has also been widely cited from the Indo-Pacific. The actual relationships

of such apparent circumtropical species complexes have never been elucidated. The aim of this

review is therefore twofold : (1) To describe and illustrate all species of Arcoidea from tropical

West Africa and (2) To examine the relationships of the west African species to those from the

Caribbean, Mediterranean and Indo-Pacific.

In both parts, data on the morphometries of the shells are frequently presented as box

plots. The box represents the range of values of the first thirty percent of the sample either side

of the mode, the projecting lines the next ten percent and the outlying points the remainder of

the values. We have used these as we feel they give a rapid visual understanding of the range of

values and the consequent variation. The box plots and all other descriptive and comparative

statistics are derived from analyses using Statview SE™.

The general discussion on zoogeographical patterns is presented in the second and concluding part of this

paper which will be published in the following issue of this Bulletin.

Abbreviations used in the text

BMNH : British Museum (Natural History) (now : The Natural History Museum), London, U.K.

MNHN : Muséum national d’Histoire naturelle, Paris, France.

NMWZ : National Museum of Wales, Dept, of Zoology, Cardiff, U.K.

SMF : Natur-Museum und Forschungsinstitut Senckenberg, Frankfurt/M., Germany.

USNM : United States National Museum, Smithsonian Institution, Washington, D.C., USA.

ZMB : Zoologisches Museum der Humboldt-Universitat Berlin, Berlin, Germany.

ZMC : Universitets Zoologisk Museum, Copenhagen, Denmark.

leg. : legit, collected by; sh. : shell, shells; spm. : specimen, specimens; sta. : sampling station;

v. : valve; RV : right valve; LV : left valve.

— 295 -

Family Arcidae

Subfamily Arcinae

Genus ARCA Linné, 1758

Type species : Area noae Linné, 1758 (SD Schmidt, 1818, ICZN Opinion 189).

Area noae Linné, 1758

(PI. I, 1A-1D, 2; fig. 1; map 1)

Area noae Linné, 1758 : 693.

Area despecta P. Fischer, 1876 : 258-259; pl. 8, fig. 1.

Type material : One marked specimen in the Linnean Collection in London (Dodge, 1952 : 143).

The holotype of Area despecta Fischer is in MNHN.

Type locality : “M. rubro, Mediterraneo, Indico” but now taken to be the Mediterranean. For A.

despecta Fischer “ littora Africae occidentalis ” but the precise locality is not recorded.

Description

Shell to 90 mm in length. Equivalve. Inflated. Inequilateral, beaks in the anterior quarter.

Outline narrowly elongate, subtrapezoidal. Posterior area long and narrow usually

slightly sulcate ; posterior angle initially carinate, becoming rounded but remaining distinct ;

posterior margin sloping outwards, usually auriculate, may be subtruncate. Median sinus

distinct in early stages but becoming obscure; ventral margin straight or sinuous usually

indented at byssal gape. Anterior margin sloping inwards, more or less straight or gently

curved. Dorsal margin very long, straight.

Dorsal area very long and may be extremely wide, more or less flat ; umbonal separation

great, umbos low. Ligament initially restricted to a triangular area between the beaks but

developing to fill most of the dorsal area. Chevrons initially symmetrical but becoming

irregular with numerous insertion sites.

Flinge plate very narrow ; teeth in two series, separation obscure but just behind the line

of the beaks. Anterior set up to 40 teeth, posterior set up to 60 teeth. Teeth minutely serrated,

more or less straight and vertical.

Sculpture primarily radial of narrow ribs, riblets and raised threads. In juveniles there are

30-35 more or less uniform riblets. In adults posterior area with 2-3 subobsolete ribs ; posterior

angle becoming smooth; postero-median zone with 5-8 narrow ribs which are not much

stronger than the 10-15 median riblets; anterior area with 4-6 riblets; all median and anterior

zones with interspace raised threads.

Periostracum usually worn remaining around byssal gape and margins, composed of

— 296 —

fragile semidiaphanous straw coloured concentric lamellae with very weak radial thickenings ;

carinal bristles broad, irregular, laminar, rarely persistent.

External background colour cream to white overlain with closely spaced buff to rust

brown oblique somewhat zigzag bands.

Adductor scars unequal, the posterior about twice the size of the anterior. Byssus

retractor elongate, triangular, extending along three quarters of the posterior hinge plate.

Selected shell measurements : For ratios of length to height, length to tumidity and length to

anterior to beak length, see figure 3 under Area bouvieri.

Distribution : Eastern Atlantic from southern Portugal (Lagos, Algarve (rare)) south to Senegal

M'Bour, 14°N); Canary Islands, Cape Verde Islands; throughout the Mediterranean.

Material examined : Mediterranean Morocco : M’diq, on beach, 2 v., leg. Gofas : Ceuta, Ensenada

de la Almadraba, 20-26 m, 1 juv. v., leg. Bouchet; south of Ceuta, 35°53'N/05°19'W, 50 m, 1 juv. v., leg.

von Cosel, both V.1986; Melilla, 1 sh., 2 v., coll. Staadt, all MNHN. Algeria : Beni Saf, 1 spm.; Oran,

6 spm., both coll. Locard, 1892; 3 sh., 1 v., coll. Pallary, 1904; 3 v., old coll.; Alger, 1 sh., 2 v., old

coll. ; all MNHN. Tunisia : Sfax, 2 v., coll. Locard, 1892; NW of Bou Grara Sea, Gulf of Gabes, 1 spm.,

some juv. v. ; Borj Djillidj, Djerba Island, 10 spm., Djerba, north coast, on beach, many v. ; Canal d’Ajim,

Djerba, 10-32 m, many spm., all leg. Bouchet & Warén, 1982; all MNHN. Greece : Euboea Channel,

1 spm., coll. Chaper, MNHN. Italy : Venice, 1 sh., coll. Monterosato, 1906; Palerme, 1 sh., coll.

Allery, 1872; Naples, 3 spm., coll. Locard, 1892; 2 sh., coll. Petit, 1873; all MNHN. Mediterranean

France : Cannes, Alpes-Maritimes, 1 spm., 2 sh., old coll. MNHN; St. Tropez, Var, 3 sh. ; Porquerolles,

Var, 1 sh. ; Sanary-sur-Mer, Var, 1 sh. ; Marseille, 3 sh. ; St. Henri, Bouches-du-Rhône. 1 sh., all coll.

Locard, 1892, MNHN. Corsica : St. Florent, 1 spm.; Bastia, 1 spm., both coll. Locard, 1892;

Propriano, on beach, 1 v., leg. Delaunay; Ajaccio, 2 spm., coll. Locard, 1882; all MNHN. Balearic

Islands : Mahon, Menorca, 5 spm., Melvill-Tomlin colin., NMWZ. Palma de Mallorca, 12 v., coll.

Soyer, 1969, MNHN. Mediterranean Spain : Cadaques, Costa Brava, 3 sh., 1 v., leg. Cherriere,

29.VIII.1966; 5 spm., both old coll. MNHN. Atlantic Morocco : Tanger, 1 spm., 1 sh., coll. Pallary,

MNHN. Canary Islands : Las Palmas, Playa Alcaravaneras, 1 sh., 3 v., in the nets of fishermen ; Playa

Las Canteras, 5 v., both leg. von Cosel, 1965, MNHN ex coll, von Cosel. West Sahara : off Cap Barbas,

21°05'N/17°14' W, 43-45 m, 2 spm., 1 v., “ Calypso ”-Sta. 1, leg. Marche-Marchad, MNHN. Maurita¬

nia : Port-Étienne (now Nouadhibou), 2 spm., 2 sh.. Mission Gruvel; Pointe des Maures (20°55'N),

intertidal, 1 spm., leg. Bouchet, V.1983; Pointe Cansado, 2 v., Mission Gruvel, 5.IV.1908; all MNHN.

Cape Verde Islands : (without precise locality) 1 v., coll, de Cessac, 1877; Santo Antâo, Punta do Sal,

5 v., leg. Cadenat; Sâo Vicente, Baia Matiota, Mindelo, 3m, 3 juv. v., leg. von Cosel, 16.XII.1978;

Razo, on beach, 1 v., leg. Schleich, VIII.1981 ; Sâo Nicolau, Tarrafal, 1 v., leg. Groh, XII.1978 ; Ilha do

Sal, Santa Maria, on beach, several juv. v. ; Boavista, Sal Rei, 1 v. ; Boavista, 1,4 miles W of Pta. Areia,

22 m, 4 v. ; Boavista, off Praia Corralhino, 10 m, 1 v. ; Sâo Tiago, northern part of Baia de Sta. Clara, 15-

35m, 1 spm. ; Sâo Tiago, 14°54'N/23°30,5' W, 15m, 1 v. ; 15°16'N/23°47' W, 55-60m, 1 v. ;

15°13,2'N/23°46,3' W, 1 juv. v. ; Fogo, SW of Sta. da Encarnacâo, 20-25 m, 1 juv. spm., 10m, 1 juv. ch.

all dredged R/V “Calypso”, leg. Marche-Marchad, XI. 1959; all MNHN. Senegal : Banc de Seminole,

43-45 m, 1 juv. spm., 3 v., leg. Marche-Marchad; Dakar, Bel-Air, Plage de la Marine, 2 sh., 3 v., leg.

von Cosel, 16.X.1988; Dakar-Hann, on beach, 1 sh., 3 v., R/V “Président Théodore Tissier”, littoral

station, 1936; Gorée, 1 spm., leg. Guilbert, 7.II. 1958; SE of Gorée, 14°41'N/17°23,3'W, 17-19 m,

1 spm., 5 v., dredged R/V “Louis Sauger”, leg. von Cosel, 24.III.1988; Cap Rouge, several juv. sh..

Mission Gruvel, III-IV.1909 ; M’Bour, Petite Côte, on beach, 1 sh., 2 v., leg. von Cosel, 22.III. 1988 ; off

M’Bour, 14°26,5'N/17°05,5'W, 10-llm, 4 spm., 6 v.; off Saloum estuary, 14°2,5'N/17°09'W, 24m, 2 v.,

both dredged R/V “Commandant Henri Gomis”, leg. Bodard, 8.XII.1966; all MNHN. Guinea : Off

Dubreka Estuary, 9°42'N/15°33' W, 35m, 1 old valve which still shows colours; off Conakry,

9°30'N/15°09,6' W, 45 m, 1 old, apparently subfossil v. ; off the border to Sierra Leone, 9°06' N/14°35' W,

52m, 1 old, app. subfossil v.; all dredged R/V “André Nizery”, leg. von Cosel, 29-30.X. 1988, all

MNHN.

— 297 —

Biotope : Area noae lives mainly on hard grounds and is byssally attached on rocks, to the undersides

of rocks and in crevices. On soft bottoms it can be found attached to isolated stones or other hard objects

including the shells of larger gastropods. The bathymetric range is from low water to about 50 m.

Remarks : See under Area bouvieri.

Fig. 1-2. — 1 : Internal view of right valve of Area noae L. Western Sahara. 2 : Internal view of right valve of Area

bouvieri Fischer. Angola. (Scales bars = 10 mm.)

Area bouvieri P. Fischer, 1874

(PI. I, 3A-D, 4; fig. 2; map 1)

Area bouvieri P. Fischer, 1874 : 206.

Area sanctahelenae Smith, 1890 : 305, pi. 22, figs. 8-8b.

Type material : The holotype (coll. Bouvier) has not been isolated in the MNHN although

Rochebrune (1881 : 250) cites it as “Sta. Vincent, Bouvier 1870, Mus. Paris.” Two paratypes (complete

specimens) from coll. Petit de la Saussaye are present and among them is the specimen figured by

Fischer (1876 : 239-240, pi. 8, fig. 2).

Type locality : Cape Verde Islands.

Description

Shell to 70 mm in length. Solid. Equivalve. Inequilateral, beaks in the anterior third.

Outline subtrapezoidal, oblong, height relatively great. In large specimens : Posterior area

relatively large ; posterior angle rounded ; posterior margin long, almost vertical, often straight

some weakly auriculate. Median area as a shallow sinus, ventral margin more or less straight

or with a shallow indentation at byssal gape. Anterior margin broadly rounded. Dorsal margin

long, straight. In small specimens : Posterior area narrow; posterior angle carinate; posterior

margin subacute, sloping inwardly, auriculate at junction with posterior carina. Median sinus

marked ; ventral margin indented. Anterior margin sloping inwardly, weakly indented. Dorsal

margin relatively very long, lateral junctions acute.

— 298 —

Dorsal area long, very wide and almost flat rising gently to low umbos. Ligament initially

restricted to triangular area between beaks but eventually covering most of the dorsal area

except for a narrow posterior strip and a very narrow anterior strip. Chevrons developing

symmetrically at first but in gerontic examples becoming irregular and often very numerous.

Hinge plate very narrow. Teeth in two series, junction just behind the beaks and

indistinct. Anterior set up to 40, posterior set up to 50 in number. All teeth finely serrated,

postero-median teeth slightly chevron shaped, remainder more or less straight and vertical.

Sculpture primarily radial of ribs, riblets and raised threads. Juveniles which about 30-35

more or less uniform riblets except for those on the posterior area which are much larger. In

large specimens : posterior and postero-median area with 8-10 rounded ribs with up to 6 raised

threads in the interspaces. Median area with numerous riblets and raised threads. Anterior

area with 4-6 ribs.

Periostracum mostly worn, retained around margins only in adult examples. Composed of

very thin, subdiaphanous, straw coloured concentric lamellae, very weakly reinforced by radial

thickenings and breaking down over ribs to give an apparent radial arrangement. In juveniles

the carinal bristles are occasionally preserved, these are greatly expanded, irregularly

spathulate and extremely fragile.

The external background colour of the shell is cream and is variously overlain with broad

oblique, sometimes zigzag bands from brick red to purplish red in colour. Larger shells

frequently have an orange tinge to the posterior area. Internal colour is mostly white except

for a brickred marginal zone.

The adductor muscle scars are subequal, the posterior a little larger. The byssus retractor

scar lies under the posterior part of the dorsal area, is an elongate triangle extending along two

thirds of the posterior hinge plate.

Selected shell measurements : See in Remark section.

Distribution : Senegal (Cape Verde Peninsula) to southern Angola (Moçamedes); Cape Verde

Islands, Sâo Tomé, Principe, Annobon; Ascension, St. Helena.

Material examined : Senegal : Dakar, SW of Madeleines Islands, 45-46 m, 3 juv. spm., 11 juv. v.,

leg. Marche-Marchad, 9.1.1954; Dakar, on Gouvernment Beach, 2 v., R/V “Président Théodore

Tissier ”, littoral station, 1936 ; Dakar, SW of Cap Manuel, 50 m, 2 v., dredged R/V “ Gérard Tréca ”, leg.

Marche-Marchad, 20.11.1956; S of Gorée, 110-112m, 1 juv. v., dredged R/V “Gérard Tréca”, leg.

Marche-Marchad, 18.11.1954; Gorée, 15-25 m, 11 spm., leg. Pin, 1987; Baie de Rufisque, 18-20m,

1 juv. spm., 5 juv. v.. Mission Gruvel, II-IV. 1909 ; off M'Bour, 14°2,5' N/17°09' W, 24m, 6 spm., 1 v„

dredged R/V “Commandant Henri Gomis”, leg. Bodard, 7.XII.1966; M’Bour, on beach, 1 v., leg. von

Cosel, 22.III. 1988; S-Casamance, off Cap Skirring, 12°25'N/17°17'W, 25 m, fine sand with stones,

1 spm., dredged R/V “ Louis Sauger”, leg. von Cosel, 27.III. 1988 ; all MNHN. Cape Verde Islands : (no

precise locality), 1 sh., coll, de Cessac, 1874; Sâo Vicente, 1 sh., 1 v., coll. Mabille, 1905; S of Santa

Luzia, 16°44'N/24°44,5'W, 52 m, coarse sand with shells and stones, 1 juv. spm., 2 v., dredged R/V

“Princess Alice II”, 1901 ; Ilha do Sal, Pedra Lume, on beach, 1 juv. sh., coll. Cadenat; Sâo Tiago,

Praia, 14°53,7'N/23°30,4'W, 25-30m, 4juv. v., dredged R/V “Calypso”, 17.XI.1959; Brava, SW of

Punta Tantâo, 20m, 1 juv. v., dredged R/V “ Calypso”, 21.XI. 1959 ; all MNHN. Guinea : off Rio Nunez,

10°27'N/15°37,5'W, 39m, mixed sand with shells and gravel, 2 spm.; off Tannah Island,

9°12'N/14°16'W, 41 m, coarse sand with stones, 4 spm., several v., both dredged R/V “André Nizery”,

leg. von Cosel, 28-30.X.1988, both MNHN. Côte d’Ivoire : off Abidjan, 5°01,5'N/3°23,5'W, 70 m, sand

— 299

Map 1. — Distribution of Area noae (circles) and A. bouvieri (squares). The empty circle indicates a record of subfossil

valves only.

with shells, 1 juv. v.; off Grand Bassam, 4°57'N/2°42'W, 40m, 1 spm., 1 v., both dredged R/V “La

Rafale”, Guinean Trawling Survey, leg. Cherbonnier, 19-22.III. 1964, both MNHN. Ghana : Cape

Coast, 26-31 m, 1 juv. spm., leg. Le Loeuff, 10.11.1968; 4°36,5'N/1°31'W, 50m, 1 v., dredged R/V

“Calypso", leg. Marche-Marchad, 24.V.1956, both MNHN. Nigeria : off Niger Delta, 4°00'N/6°H'E,

34m, 3 spm.; 4°03'N/6°12'E, 32m, 10 juv. v., both dredged R/V “Calypso”, 26.V. 1956, leg. Marche-

Marchad, both MNHN. Ilha do Principe : Between Pta. da Mina and I. Santa Ana, 10-12 m, 1 spm.,

1 sh. ; 1°42,5'N/7°28' E, 21m, algues calcaires, 1 spm.; 1°43'N/7°29'E, 37 m, 1 spm.; 1°43'N/7°28,4'E,

73m, 1 spm., 1 v.; r33'N/7°31'E, 90m, 1 juv. spm.; all dredged R/V “Calypso”, leg. Marche-

Marchad, 24.VI-1.VII.1956, MNHN. Sâo Tome : off Baia de Ana de Chaves, 5m, calcareous algae,

1 spm.; off Praia Lagarto, 5-6 m, 1 spm.; off Diego Nunes, 0°23'N/6°43' E, 30 m, 1 spm.; north coast.

300

0°25,5' N/6°40' E, 50 m, 1 juv. spm., all dredged R/V “Calypso”, leg. Marche-Marchad, 11-21.VI.1956;

all MNHN. Annobon : (without precise locality), 60m, 3 juv. sh., coll. Cavelier de Cuverville, 1886;

north of Santo Antonio, 23 m, calcareous algae, 2 spm., dredged R/V “ Calypso ”, leg. Marche-

Marchad, 4.VII.1956; all MNHN. Equatorial Guinea : Bata, 1 sh., coll. Pobeguin, 1891, MNHN.

Gabon : Pont-Gentil, Ile aux Pigeons, 3 m, on mangrove roots and Pinna , 5 spm., leg. Chevalier, 1984-

89, MNHN. R. P. Congo : Pointe-Noire, plage Sauvage, 2 v., leg. von Cosel, 10.XII.1985, MNHN.

Angola : Barra do Dande, Bengo province, on rocks at low tide, 1 spm. ; Cacuaco, Bengo province, on

rocks at low tide, 1 spm.; 5-10m, 9 juv. spm., 8 juv. v. ; Ilha de Luanda, Luanda province, 40-60m,

1 spm.; Corimba, Luanda province, 10-20m, numerous spm.; Palmeirinhas, Luanda province, on rocks

at low tide, 1 spm.; Cabo Ledo, Luanda province, 3 juv. spm., 3 juv. v. ; Baia de Canoco, Benguela

province, 2 juv. spm.; Praia Amelia, Moçâmedes, 40-60m, 2 spm., all leg. Gofas, 1981-86, MNHN.

Biotope : Byssally attached on hard substrates such as rocks, stones, shell agglomerations and

secondary hard substrates like shells or small stones on sand, mostly with calcareous algae. Bathymetric

range from sublittoral to 60 m.

Remarks

Area bouvieri and A. noae have overlapping ranges only in the Senegal and Cap Verde

regions. They can be separated at all sizes by the differences in shell shape (fig. 3) and

sculpture. Area bouvieri is less elongate, more compressed and less inequilateral than A. noae.

The radial ribs of A. bouvieri are much stronger especially over the posterior area.

Fig. 3. — Box plots of the ratios of Total Shell Length to Height (L/H), Tumidity (L/T) and Anterior to Beak Length

(L/A-Bk) of Area bouvieri (n = 20) and Area noae (n = 20).

Area bouvieri belongs to the A. noae group of species which is represented in the

Caribbean by A. zebra , in the Indo-Pacific by A. navicularis and in the Panamic Pacific by A.

pacifica. A. bouvieri differs from all of these in its relatively short quadrate outline and the

large difference between the median and lateral sculpture. In these respects it differs most from

A. noae and is closer to A. zebra and A. navicularis.

We can find no reason to regard A. sanctahelenae Smith as distinct from A. bouvieri. It

- 301 -

would appear that Smith (1890) overlooked Fischer’s species as he compares the St. Helena

material only with A. noae and A. navicular is. Lamy (1907 : 24) also considered A.

sanctahelenae to be a synonym.

Area avellana turbatrix n. subsp.

(PI. II, 1A-D, 2; fig. 7; map 2)

Type material : Holotype (28.3mm), MNHN, Santo Antonio, Benguela province, Angola;

intertidal, rocks; leg. Gofas. Paratypes MNHN: 2 spm. as holotype; 2 spm. Lucira, Moçâmedes

province, Angola ; NMWZ : 8 spm. Corimba, Moçâmedes province, Angola ; all leg. Gofas.

Type locality : Santo Antonio, Benguela province, Angola.

Description

Shell to 35 mm in length. Equivalve. Inflated. Inequilateral, beaks in the anterior third.

Outline subtrapezoidal, posterior area demarcated by a strong posterior angle which is

often carinate. If small and not distorted then ; longer than high ; posterior margin obliquely

truncate usually slightly auriculate, posterior ventral junction acute ; ventral margin straight,

gently curving or slightly indented by byssal gape ; anterior margin broadly rounded ; dorsal

margin long straight, dorsal lateral junctions angular. Posterior area well demarcated by

carinate posterior ridge, median sinus not apparent. If large then usually deformed to some

degree and then : some remaining longer than high others almost as high as long; posterior

margin obliquely subtruncate, posterior ventral junction angular or narrowly rounded ; ventral

margin variously indented byssal gape which may be extensive; anterior margin rounded,

straight or irregular.

Dorsal area large, broadening rapidly with wide imbonal separation. Ligament extensive,

covering dorsal area, chevrons irregular, developing rapidly and numbering up to 10 in

gerondic specimens.

Hinge plate narrow, teeth small in two series but separation obscure, anterior set up to

38 teeth, posterior set up to 43 teeth. All teeth minutely serrated and with a frontal groove;

posterior marginal teeth becoming chevron shaped, others straight and vertical.

Sculpture on posterior area of larger shells of 5-8 ribs, the first three from the posterior

carina most prominent and usually at least one bifid. Towards dorsal margin ribs smaller,

more variable in size, some as interspace riblets; of smaller shells usually of 4-5 simple ribs.

Median area frequently divided by a weak posterior median ridge, posterior section with 15-20

nodulose riblets, anterior section and anterior area with 25-30 radial riblets variously with

interspace radial threads. In most specimens the radial element is dominant but in more

elongate examples the concentric element is equally expressed especially on the posterior

median zone.

Periostracum rarely well preserved but usually present around byssal gape and remnants

on posterior carina. Posterior carina with a single row of large, spathulate bristles which are

smooth on the anterior edge and coarsely serrated on the posterior edge, they are thin, fragile

and straw coloured (pi. II, 1A). On the posterior area short lamellar elements are present

between the ribs and are reinforced by weak slightly emergent hairs. On the remainder it is

concentrically lamellar but breaks down into radially arranged segments which are weakly

reinforced emergent hairs.

Shell generally pale in colour usually with mauve-brown tinges along the posterior border,

occasionally extending throughout the posterior third, over the hinge plate and onto the

anterior area, some darker brown on posterior area. Mantle pigmentation absent except for

the black eyespots.

Selected shell measurements : See figure 4.

Distribution : From Guinea (Conakry area) south to Cameroon and Angola (Luanda).

Material examined : Senegal : S of Cap Skirring, S-Casamance, 2 worn v., on beach, leg. von

Cosel, 3-6.III. 1988, MNHN. Guinea : Roume, Iles de Los, beach on the N-side, 2 v., leg. von Cosel,

29.V. 1988; Kassa, Iles de Los, E-Side, N of village, on the undersides of boulders and stones with very

thin layer of mud on them, low tide, 2 spm., leg. von Cosel, 12.XI.1988, both MNHN. Liberia :

5°21,5'N/9°54,5'W, 73-80m, 1 v., dredged R/V “Calypso”, leg. Marche-Marchad, 20.V.1956, MNHN.

Sào Tome : Praia Emilia, under stones at low tide, 1 spm., leg. Gofas, XI. 1983, MNHN. Cameroon :

Victoria (now Limbe), Morton Bay, 2 spm., 1 v; Mondoleh Island, Ambas Bay, 6 spm., all under stones

at low tide, leg. von Cosel, IV. 1969 and XI. 1985, MNHN. Gabon : Cap Esterias-Pointe Idolo, on stones

in sand at low tide, 3 spm., 1 v., leg. von Cosel, MNHN; (no precise locality), 6 spm., coll. H. Fischer,

MNHN. R.P. Congo : Pointe-Noire, Plage ORSTOM, 3-6 m, many v. ; Plage Mondaine, on beach,

many v. ; Songolo, 3-5m, 3 v. ; Plage Sauvage, on beach, 3 v., all leg. von Cosel, XI-XII.1985; Pointe-

Noire, 6 spm., 6 v., coll. Office Pte.-Noire; Pointe-Noire, 5 spm., coll. Aubert de la Rue; all MNHN.

Angola : Ambrizete, Zaïre province, 1 spm., 1 v. ; Barra do Dande, Bengo province, 6 spm. ; Cucuaco,

Bengo province, 1 spm.; Praia Etambar, Corimba, Luanda province, 10 spm.; Caotinha, Benguela

province, 4 spm., all leg. Gofas, MNHN.

Biotope : Byssally attached to stones and rocks, mostly on the undersides. This species appears to

prefer more or less turbid waters and is also found in areas with slightly reduced salinities during the rainy

season. Bathymetric range from low intertidal to sublittoral.

Derivatio nominis ; turbatrix, Latin, f. the “disturber” or “trouble maker” making reference to the

systematic confusion prevalent in this group of species.

Remarks

This is the tropical West African species referred to as Area imbricata Bruguière of

authors. Its identity has never been examined in any detail and it is assumed that it was

identified as that species on geographical considerations alone. The distinctions between the

Caribbean form known as A. imbricata and its Indo-Pacific counterpart. A. avellana Lamarck

are similarly obscure. We have examined these in relation to the West African form and make

the following observations :

Character

Indo-Pacific

West African

Caribbean

Size

To 50 mm.

To 35 mm.

To 65 mm.

Posterior sculpture

Ribs often irregular,

occasionally bifid.

Ribs often irregular,

usually bifid.

Ribs mostly regular,

rarely bifid

Periostracal insertion marks

Lacking

Present

Ligament chevron N°

Medium

High

Low

Umbonal separation

Wide

Very wide

Moderate

Carinal bristles

Large, fragile

straw coloured

Large, fragile

straw coloured

Very large, robust

greyish

Internal shell colour

Usually partly white

Mostly white

Usually dark overall

Mantle colour

Patterned shades of

brown

White except for eye

spots

Patterned shades of

brown

Area avellana (Indo-Pacific) (pi. II, 4) : This form has a larger maximum size but the

general form of the shell, sculpture and periostracum are so similar that we are unable to

identify significant differences. Only the umbonal separation and relative number of ligament

chevrons show a difference (figs. 5 & 6). The colouration pattern is similar but there does seem

to be a greater incidence of dark coloured specimens from the Indo-Pacific and this may also

be reflected in the greater pigmentation of the mantle.

Area imbricata (Caribbean) (pi. II, 3A-B) : The Caribbean form attains a much larger

maximum size and in general is much less distorted. The shells are frequently more elongate

and the ribs on the posterior area are rarely bifid but bear short grooves which represent the

insertion points of the periostracal bristles. Umbonal separation is relatively small and the

number of ligament chevrons is relatively fewer. The internal colouration is frequently darker

with most specimens coloured throughout and many being chocolate brown or black. Most

significantly however are the carinal periostracal bristles which are approximately twice the

size, more strongly reinforced and more persistent (pi. IX, B).

From these comparisons it would appear that the West African form is more closely allied

to that of the Indo-Pacific than it is to that of the Caribbean. However we have not addressed

the possibility that these differences are merely ecophenotypic or of regional significance only.

We suggest that as the total range of variation is not seen in all three groups that there is at

least some regional significance. Even so this may reflect the absence of certain habitats in a

region and in West Africa the exclusion of coral reef communities may be important. The

habitats described here of the West African population are unusual in that the preference

seems to be for turbid intertidal areas which are in contrast to the coral reef association with

clear water in the tropical regions of the Caribbean and Indo-Pacific. Of the characters cited

we view the carinal bristles to be most relevant as it is difficult to envisage the functional

significance of the differences noted. The umbonal separation and ligament chevrons are

related to growth with both having an allometric relationships to shell size (Thomas, 1976;

304 —

Fig. 4-6. — 4 : Box plots of the ratios of Total Shell Length to Height (L/H). Tumidity (L/T) and Anterior to Beak

Length (L/A-Bk) of Area avellana turbatrix (n = 25). 5 : Graphs of Umbonal separation plotted against Shell

Length for four samples of the Area imbricata complex. Florida and Guadeloupe are A. imbricala, Seychelles is A.

avellana and West Africa is A. a. turbatrix. 6 : Graphs of ligament chevron number plotted against shell length for

four samples of the Area imbricata complex. Florida and Guadeloupe are A. imbricata , Seychelles is A. avellana and

West Africa is A. a. turbatrix.

Oliver and Allen, 1980). The differences observed in these could be related to growth rate

and if the West African population was restricted to less favourable conditions the allometry

would then occur in the smaller size classes. The only meaningful way forward would be to

carry out studies related to the genetic make up of each population but this is beyond the

scope of the material at hand.

Resorting to traditional techniques we conclude that the West African form is most

closely allied to that of the Indo-Pacific but the differences observed may be due to regional

environmental conditions. However both populations are geographically isolated as the Indian

Ocean populations do not spread beyond the province of Natal and the West African form is

restricted to the Gulf of Guinea north of Namibia. Consequently we have given subspecific

status to the West African form as A. avellana turbatrix but not in keeping with tradition

regard it as distinct from the Caribbean form A. imbricata. If one views the differences to be

insignificant then one cannot regard the Caribbean and Indo-Pacific forms to be distinct either

— 305 —

and neither would the distinction of the Panamic Pacific form known as A. mutabilis be

justifiable. The whole complex would then have to be regarded as a single cosmopolitan species

taking the earliest name of A. imbricata Bruguière. This is the position adopted by Lamy

(1907 : 26-38) but he accepted three varieties within the Indo-Pacific ad West African ranges,

namely var. arabica Philippi, var. avellana Lamarck, and var. martensi Dunker. He also

isolated the Caribbean form as the nominate species A. imbricata.

Fig. 7-8. — 7 : Internal view of right valve of Area avellana turbatrix n. ssp. Angola. 8 : Internal view of right valve of

Area retragona Poli. Ireland. (Scales bars = 5 mm.)

Area tetragona Poli, 1795

(PI. II, 5A-B, 6 ; fig. 8 ; map 2)

Area tetragona Poli, 1795 : 137.

Type material : Not located.

Type locality : Sicily.

Description

Shell to 40 mm in length. Equivalve. Inflated if growth is unhindered but may be

compressed if constricted in crevices. Inequilateral, beak position variable, in the anterior third

in regular specimens but only just in front of the mid line in some distorted examples.

Outline subtrapezoisal, angular, juveniles elongate, adults irregular oblong. Posterior area

narrow, well demarcated by the posterior angle which remains sharply carinate; posterior

margin oblique, more or less straight, some very weakly auriculate. Median area not

depressed, ventral margin gently curved or sinuate at byssal gape. Anterior margin rounded,

variable. Dorsal margin long, straight.

Dorsal area wide to very wide, usually flat but may be cleft in distorted examples ; umbos

very low. Ligament with unusual growth pattern ; initially with two strips of fibrous ligament

radiating from the beaks, between these and to either side of them the dorsal area is free of

ligament material. Lamellar chevrons are added mostly within the anterior strip then to the

posterior strip and finally new sites of ligament growth appear along the hinge line between the

— 306 -

original strips so that in the largest shells most of the dorsal area is covered. The chevrons are

very narrow and may reach 25 in number.

Hinge plate narrow, teeth in two series, separation obscure at a point behind the umbonal

line; anterior set up to 30 teeth, posterior set up to 15 teeth. Teeth minutely serrated anterior

teeth small, some chevron shaped, mostly vertical but marginal teeth oblique ; posterior teeth

straight but becoming progressively oblique towards the margin where they are subparallel.

Sculpture of radial riblets and raised threads, initially with 4-5 riblets on the posterior

area and 30-35 finer riblets on the remainder, carinal riblet bifid often imbricate. Subsequently

posterior riblets divide and are added to by interspace threads. Median area with closely

spaced, somewhat acute riblets contrasting slightly with the more rounded and slightly broader

riblets on the anterior area.

Periostracum usually lost, persistent around margins and on the posterior area only.

Composed of concentric lamellae reinforced by bristles arising from the riblet interspaces,

most often the lamellar part is worm and the arrangement appears simply radial. The bristles

become spicate on the postero-median and posterior areas. The carinal bristles are large,

lanceolate but with irregular margins. All the bristles are dark coloured from brown to black.

Shell colouration is weak, mostly greyish white but with some brown tinges internally

over the posterior area.

Adductor scars small, subequal ; both with myophoric ridges extending into the umbonal

cavity. Byssal retractor small, triangular restricted to the posterior half of the shortened

posterior hinge plate.

Distribution : Shetlands to Morocco (Essaouira/Mogador), the Azores and throughout the

Mediterranean.

Material examined : Ireland : St. Johns Pt., Donegal, 5 spm., leg. P. G. Oliver, Berehaven, Bantry

Bay, 9 spm., leg. J. T. Marshall; both NMWZ. England : Falmouth, leg. J. T. Marshall, 8 spm.,

NMWZ. Celtic Sea : 8 stations between 49°15' and 48°33'N and 05°09' and 05°28,5'W, 102-112m, 15 v.,

all dredged R/V “Thalassa”, leg. von Cosel, XII. 1983, MNHN. Atlantic France : Brest. Finistère, 2 sh.;

Forient, Morbihan, 3 spm.; Belle-Ile, Morbihan, 1 sh.; Le Croisic, Loire-Atlantique, 4 spm.; lie d'Yeu,

Vendée, 2 spm.; Ile d’Oléron, Charente-Maritime, 3 spm., all. coll. Locard, 1982; Golfe de Gascogne

(Biscay), 18 spm., coll. Denis; Arcachon, Gironde, 1 spm., coll. Roche, 1894; St-Jean-de-Luz, Basses-

Pyrénées, numerous sh. and v., coll. H. Fischer, 1898; all MNHN. Atlantic Spain : Ceuta, Strait of

Gibraltar, Punta Almina, 25-40 m, 6 spm., 1 v., leg. Bouchet, Gofas & Lozouet, V.1986, MNHN.

Algeria : Oran, 40m, 2 spm., 2 sh., coll. Pallary; 60m, 3 spm., coll. Locard, 1892; Alger, 4 juv. sh.,

1 v., old coll., all MNHN. Italy : Palermo, Sicily, 11 spm., 3 sh., coll. Jousseaume, 1916; 3 spm., 2 sh.,

coll. Allery, 1872; 7 spm., coll. Monterosato, 1906; Naples, 5 spm., 4 sh., coll. Petit, 1873; 4 spm.,

2 sh., old coll; 1 v., coll. Monterosato, 1906; Capri, 3 spm., coll. Locard, 1892; all MNHN.

Mediterranean France: Nice, Alpes-Maritimes, lspm.; St. Raphaël, Var, 3 spm. ; St. Tropez, Var,

2 spm., all coll. Locard, 1892; Toulon, Var, 1 spm., old coll.; Marseille, Bouches-du-Rhône, 9 spm.,

coll. Locard, 1892; 1 spm., coll. Vayssière, 1907; Sète, Hérault, 2 spm., coll. Locard, 1892; Banyuls-

sur-Mer, Pyrénées-Orientales, 8 spm., coll. Lab. Arago, 1904; 4 spm., old coll., all MNHN. Corsica : St.

Florent, N-coast, 2 spm., coll. Locard, 1892, MNHN. Atlantic Morocco : Mogador (now Essaouira),

6 spm., coll. Pallary, MNHN. Azores : Ponta Delgada, Sâo Miguel, 10-20m, 2 spm., 5 v., leg. Bouchet,

9-15.VII. 1983, MNHN. 25 lots with numerous spm., sh. and v., from Sâo Miguel, Terceira, Faial channel

and Flores, between 39 and 225 m, empty shells and valves washed down on the steep slope to 1675 m, all

dredged R/V “Jean Charcot”, BIACORES-Expedition, leg. Métivier, X.1971, all MNHN.

Biotope : Byssally attached to rocks in crevices or in more open situations in tranquil sites such as

those at depth. Bathymetric range from low in the intertidal to 100 m.

308

Ri marks : This species probably cannot be considered to be a component of the tropical

West African fauna but as it can be confused with Area avellana turbatrix and juveniles of

Area noae we have included it here. Even when distorted it can be easily separated on the form

of the ligament and periostracal bristles.

Genus ACAR Gray, 1857

Type species : Area gradata Broderip and Sowerby, 1829 (SD Woodring, 1925).

Acar cf. plicata (Dillwyn, 1817)

(PI. II, 7A-B ; fig. 10; map 3)

Area plicata Dillwyn, 1817 : 227-228.

Type material : Based on the figure in Chemnitz (1795 : 244, pi. 204, fig. 2008).

Type locality : Red Sea.

Description

Shell to 26 mm in length. Equivalve. Initially slightly compressed but soon becoming

rather tumid to very tumid in gerontic specimens (the onset of the gerontic expansion can

occur in a wide range of sizes). Inequilateral, beaks in the anterior 1/4 rather low.

Outline subrectangular-subtrapezoidal, anteriorly usually slightly narrowed ; frequently

distorted especially in gerontic examples. Posterior area narrow, demarcated by a persistent

posterior carinal ridge ; posterior margin oblique, posterior ventral junction subacute. Median

area flat to weakly sulcate ; ventral margin more or less straight but often sinuous ; byssal gape

obsolete or very narrow. Anterior area small, demarcated by a rounded ridge ; anterior margin

broadly rounded. Dorsal margin straight.

Dorsal area usually very narrow, wider anterior to the beaks but becoming wide overall in

gerontic specimens; umbonal separation usually slight. Ligament restricted to well behind the

beaks, chevrons very narrow, numbering up to 8 in normal specimens but as many as 20 in

gerontic examples.

Hinge plate narrow to moderate, teeth in 2 series but separation obsolete except in old

specimens where ligament growth has eroded the small central teeth; anterior set up to

10 teeth, posterior set up to 15 teeth. Teeth strong, anterior laminar, posterior chevron

shaped, all coarsely serrated, marginal teeth becoming very oblique. In gerontic specimens the

teeth may be irregular, often divided medially.

Sculpture imbricate, of up to 30 rather broad concentric ridges dissected by 25-35 radial

ribs these dividing during growth to number up to 50. The resulting vesicular nodes are

smoothly rounded except on the posterior angle where they may be incomplete and therefore

slightly plicate. The posterior area bears 5-7 strong ribs on which the nodes are greatly swollen

309

giving the cross section of the posterior margin a strongly corrugated appearance. This is a

little less so for the Cape Verde Islands material.

Periostracum very thin, rarely retained.

Shell whitish, exterior rather dirty cream; interior of Cape Verde, Sâo Tomé and

Annobon specimens mostly flushed with pale orange/pink, the Angolan material rarely so.

Adductor scars more or less equal, raised with myophoric flanges along their inner edges.

Inner lateral margins crenulate, ventral margin weakly so or irregularly denticulate.

Selected shell measurements : See figure 9.

UH L/T L/A-Bk

Fig. 9. — Box plots of the ratios of Total Shell Length to Height (L/H), Tumidity (L/T) and Anterior to Beak Length

(L/A-Bk) of Acar cf. plicata from West Africa (n = 24).

Distribution : This species occurs from the Cape Verde Islands south to Angola but it is most

common on the Cape Verde Islands, the islands in the Gulf of Guinea and on the coast of Angola.

Material examined : Cape Verde Islands : (no precise locality), numerous spm. and v., leg. Rang,

1837; 4 spm., coll, de Cessac; 5 spm., coll. Bouvier; Santo Antâo (no precise locality), 5 v. ; Sâo Vicente,

Baia Matiota, Mindelo, on the undersides of stones, 1-2,5 m, 3 spm., 2 v. ; Sâo Vicente, Baia Porto

Grande, 2 sh., 10 v., both leg. von Cosel, XII.1978; Ilha do Sal, (no precise locality), numerous spm., sh.

and v., leg. Cadenat, 1950; Ilha do Sal, Palmeira, undersides of rocks at low tide, 7 spm.; Ilha do Sal,

Baia Algodoeiro, on beach, 4 v. ; Ilha do Sal, Santa Maria, underside of boulders 2-3 m, 3 spm., all leg.

von Cosel, 15.XII.1978-1.1.1979; Ilha do Sal, 16°35'N/22°55'W, calcareous algae, 15m, 1 spm., dredged

R/V “Calypso”, 26.XI.1959; Boavista, Gatas (Punta Rodrigo), on the undersides of stones on mixed

sand, l,5-2m, 6 spm., leg. von Cosel, 27.XII.1978; Sâo Tiago, Praia, 8 v., leg. Cadenat, 1950; Sâo

Tiago, Porto de Praia, four lots with 3 spm. and 7 v., from 2 to 30m, all dredged R/V “Calypso”, 17-

19.XI.1959; Brava SW of Punta Tantâo, 20m, 3 v. ; Fogo, SW of Santa da Encarnacâo, 20-25m,

12spm. ; Fogo, Punta da Araia, 2.5m, 2 spm. both dredged R/V “Calypso”, 20.XI.1959; all MNITN.

Senegal : Dakar, SW of Cap Manuel, 50m, 1 v. ; Dakar, 129-150m, 1 v., both dredged R/V “Gérard

Tréca”, leg. Marche-Marchad, 1956 and 1958, MNHN, Liberia ; 5°21,5'N/9°54,5'W, 73-80m, 4 v„

dredged R/V “Calypso”, leg. Marche-Marchad, 20.V. 1956, MNHN. Côte d’Ivoire : Abidjan region (no

precise locality), 2 v., leg. Le Loeuff, MNHN. Ilha do Principe : W-coast, 1°37'N/7°22'E, 30 m, 1 v. ;

Baia de Santo Antonio, between Punta da Mina and Punta de Novo Destino, 6 m, 1 v. ; Baia Santo

Antonio, between Punta da Mina and Ilheu Santa Ana, 10-12 m, 1 spm.; both dredged R/V “Calypso”,

leg. Marche-Marchad, VI.1956, MNHN. Sâo Tome : Punta Diogo Vaz, west coast, 30m, 1 spm.;

1°38,4'N/7°22,1'E, 31m, 1 spm.; off S. Tomé city, 0°20'N/6°45'E, 10m, 2 spm., 5 v. ; off Praia Lagarto,

— 310 —

Map 3. — Distribution of Acar cf. plicata (circles), A. plicata (shaded area) and A. pulchella (squares).

— 311 -

5-6m, 5 spin., all dredged R/V “Calypso”, leg. Marche-Marchad, 11 -27,VI, 1956; all MNHN.

Annobon : N of Santo Antonio, 23m, 1 spm. ; 1°25,2'S/5°36,l'E, 20m, 1 spm., both dredged R/V

“Calypso”, leg. Marche-Marchad, VI and VII.1956; 1°24'S/5°37,5'E, 20-40m, 1 spm., 1 v., leg.

Crosnier, 11.XII.1965; 1°28,5'S/5°37,5'E, 35-55m, 3 spm., leg. Poinsard, 16.VI. 1967; all MNHN. R.P.

Congo : Pointe-Noire, Plage Mondaine, N of lighthouse, low tide, 7 v. ; Plage Sauvage, on beach, 1 v. ;

Plage ORSTOM, coarse sand and stones, 5-7m, 1 v„ all leg. von Cosel, XI-XII.1985, all MNHN;

Loango, 4 v., leg. Office Pointe-Noire, 1969, MNHN. Angola : Cabo Ledo, Luanda province, 10-40 m,

2 spm. ; Praia Etambar, Corimba, Luanda province, rocks, infralittoral, many spm. ; Baia do Mussulo,

Luanda province, 5 spm.; Baia de Santa Maria, Benguela province, rocks, 0-2m, 18 spm.; Caotinha,

Benguela province, rocks, infralittoral, 7 spm. ; Baia do Limagem, Benguela province, rocks, 0-2 m,

1 spm. ; Baia de Lucira (Bissonga), Moçâmedes province, intertidal, 4 spm. ; Lucira (Praia do Cesar),

Moçâmedes province, infralittoral, 3 spm. ; Baia das Pipas, Moçâmedes province, rocks, 2 spm. ; Sâo

Nicolau, Moçâmedes province, intertidal, 3 spm. ; Praia Amelia, Moçâmedes province, rocks, infralittoral,

2 spm., all leg. S. Gofas, 1982-1984, MNHN.

Biotope : This species lives in crevices and under rocks where it is attached by a weak byssus. It is

found from low in the intertidal to 40 m.

Fig. 10. — Internal view of right valve of Acar cf. plicata (Dillwyn). Sâo Tomé. (Scale bar = 5 mm.)

Remarks

The genus Acar is distinctive with its coarse imbricate sculpture and raised muscle scars

but the species systematics are very complex. Traditionally the species are identified on their

geographic distribution such that A. plicata is Indo-Pacific, A. pulchella (Reeve, 1844) is

Mediterranean, A. domingensis (Lamarck, 1819) is Caribbean and A. gradata (Broderip &

Sowerby, 1829) is Panamic. The West African form has been known by all but the Panamic

name. Rost (1955) in discussing A. gradata mentioned the coarse and fine sculptured varieties

of that species and we have observed the same feature in the Caribbean A. domingensis but not

to any great extent in the West African form. Even in the coarse sculptured form of A.

domingensis the nodes never appear to be so inflated as in the West African material and the

posterior ribs are finer or lower. The orange/pink colouration is apparently absent from

Caribbean material. In sculptural coarseness the Indo-Pacific A. plicata is very similar but

generally as the name implies the concentric elements are more lamellar especially on the

posterior angle which often appears foliate. The posterior ribs are similar in development but

312 —

again the nodes are not inflated or entire but are rather the form of domed plications. As with

the West African form the frequency of orange/pink shells is rather great. Acar pulchella

(pi. II. 8A-B) from the Mediterranean is a small species rarely exceeding 15 mm and differs

from all others in that the sculpture is primarily of fluted, concentric, slightly elevated lamellae.

The distinctions rest therefore on the coarseness of the sculpture and the degree to which

the radial and concentric elements fuse into either vesicular nodes of fluted lamellae. Given the

great range in variation we are refraining from giving the West African material separate

nomenclatural status. From our observations the similarities in coarseness of sculpture,

distinctiveness of the posterior ribs, size and colour we conclude that the West African form is

closer to that of the Indo-Pacific. Meyer (1868) in discussing the Tertiary forms of Acar

suggested that A. clathrata (Defrance, 1816) was replaced by the Recent A. pulchella. In

general form the Pliocene species is close to A. plicata and could also be the fossil equivalent of

the West African form. We recognise the affinity of the West African and Indo-Pacific forms

by using the name A. plicata.

Genus BARBATIA Gray, 1842

Type species : Area barbata Linné, 1758 (SD Gray, 1857).

Barbatia complanata (Bruguière, 1789)

(PI. Ill, 1A-B, 2, 3, 4, 5A-B ; fig. 6; map 4)

Area complanata Chemnitz, 1784 : 198, pi. 55, fig. 544.

Area complanata Bruguière, 1789 : 100.

Area stigmosa Dunker, 1853 : 46, pi. 9, figs. 8-11.

Type material : The type is based on the figure given by Chemnitz (1784) and the specimen may be

in the ZMC, Copenhagen. The type of A. stigmosa is probably in ZMB Berlin.

Type locality : This is cited as “Guinea” by Chemnitz which refers to tropical west Africa.

Bruguière cites Madagascar and O. Americano but this is erroneous and arises from the early belief that

there was only a single pan-tropical species.

Description

Shell to 50 mm in length but usually not exceeding 35 mm. Equivalve. Compressed.

Inequilateral, beaks in the anterior third.

Outline subrectangular-subtrapezoidal, often somewhat distorted (some to the extent of

being subtrigonal), the anterior usually a little narrower. Posterior area poorly demarcated by

a low weakly angled posterior ridged but more noticeably by the change in the size of the ribs ;

posterior margin oblique, more or less straight to gently curved, posterior ventral junction

roundly subacute. Median area weakly sulcate ; ventral margin subparallel to dorsal margin to

inclined towards the anterior, more or less straight or indented or distorted especially at byssal

— 313

gape which is rather long but not very wide. Anterior area small, demarcated by a weak

rounded ridge, anterior margin broadly rounded but often restricted and the oblique, slanting

inwards. Dorsal margin long, straight.

Dorsal area narrow to very narrow, becoming deeply cleft, umbonal separation slight.

Ligament initially opisthodetic, rapidly the dorsal area and extending anteriorly well beyond

the beaks; chevrons narrow, numerous in gerontic specimens, numbering up to 12.

Hinge plate rather narrow especially centrally, teeth in two series which are almost

inseparable, total teeth count up to 45. Central teeth very small, often destroyed by ligament

incursion, lateral teeth laminar or chevron shaped, becoming strongly oblique.

Sculpture of numerous radial riblets and ribs ; posterior area with 6-7 large ribs often with

1-3 small secondary riblets. In some, the primaries are bifid, not greatly elevated, well spaced

and evenly dissected giving the appearance of a twisted rope ; anterior and median areas with

55-60 primary riblets, the anterior and those adjacent to the posterior angle a little larger than

the more closely spaced median riblets, posterior median riblets bifurcating at an early stage.

All radial elements dissected by concentric element and therefore appearing nodulose,

concentric element also present as widely spaced low ridges caused by the enlargement of the

nodules at regular intervals, these correspond with the concentric rows of larger periostracal

bristles.

Periostracum with a primarily concentric arrangement of raised lamellae strengthened by

slightly emergent bristles arising from the interspaces ; the lamellae usually break down into

rectangular sections to give a frilled appearance; lamellae pale straw coloured, emergent

bristles brown giving a very characteristic pattern.

Shell white.

Adductor scars subequal the posterior a little larger, posterior pedal/byssal retractor scar

small, elongate. Inner margin finely crenulate.

Selected shell measurements : See figure 11.

Distribution : This species ranges from Guinea (Conakry area) and the Cape Verde Islands (where

it is rare) south to southern Angola and is also found in Sâo Tome, Principe and Annobon.

Material examined : Cape Verde Islands : Ilha do Sal (no precise locality), 1 dwarf spm., leg.

Cadenat, IV-VI.1950, MNHN. Guinea : Kassa, Iles de Los, E-side, N of village, on the underside of a

stone, at low tide, 1 spm., leg. von Cosel, 12.XI.1988, MNHN. Liberia : 6°40'N/H°23' W, 51 m, 1 juv. v.

dredged R/V “Calypso”, leg. Marche-Marchad, 19.V. 1956, MNHN. Côte d’Ivoire : off Tabou,

4°16,5'N/7°30'W, hard bottom, 40m, dredged R/V “La Rafale”, Guinean Trawling Survey, leg.

Cherbonnier, 8.IV. 1964; Abidjan region, “Palm Beach”, on rocks, 6-10m, 1 spm.; Canal de Vridi,

Abidjan, 6 spm., 1 sh., 3 v. ; Abidjan, SE of “2 Poteaux”, on sandstone, 37m, 1 juv. spm., all leg. Le

Loeuff, 1967-1973; all MNHN. Ghana : Cape Coast, hard bottom, 26-31 m, 1 spm., leg. Le Loeuff,

10.11.1968; 4°37'N/0°50'W, 90-100m, 3 v., dredged R/V “Calypso”, leg. Marche-Marchad, 24.V.1956,

both MNHN. Togo : 6°10'N/1°37'E, 19m, 2 juv. spm., leg. Crosnier, 26.VII.1964, MNHN. Benin :

Ouidah, 6°10'N/2°05'E, 100m, 5 juv. v., leg. Marche-Marchad, 22.XI.1958, MNHN. Nigeria : off the

Niger delta, 4°00'N/6°1TE, 34m, on Chama , 1 juv. spm., dredged R/V “Calypso”, leg. Marche-

Marchad, 26.V. 1956, MNHN. Cameroon : Victoria (now Limbe), Morton Bay, E-side, between rocks at

low tide 14 spm., leg. von Cosel, 1-3.XII.1985 ; Mondoleh Island, Ambas Bay, under and between stones

near low tide, numerous spm., leg. von Cosel, IV.1969 ; Kribi, on beach, 8 v., leg. Nicklès, 1947 ; 3 spm.,

leg. von Cosel, IV. 1969; off Kribi, 2°36,8'N/9°46' E, 1 spm.; 2°33,3' N/9°42,6' E, 1 spm., both leg.

Crosnier, XII. 1962; all MNHN. Ilha do Principe : Baia de Santo Antonio, 6-15 m, 4 spm., 1 sh., 8 v. ;

Baia das Agulhas, 4-8 m, lspm.; 1°37'N/7°22'E, 30 m, 3 juv. v. ; 1°42'N/7°28,8'E, 37 m, lspm.;

— 314 —

Fig. 11. — Box plots of the ratios of Total Shell Length to Height (L/H), Tumidity (L/T) and Anterior to Beak

Length (L/A-Bk) of Barbalia complanata from West Africa (n = 14).

Map 4. — Distribution of Barbalia complanata.

1°20,7'N/7°17,6'E, 25-40m, 1 dwarf spm., all dredged R/V “Calypso”, leg. Marche-Marchad, 25.VI-

1.VII.1956; all MNHN. Sào Tome : Esprainha, near Neves, 3 spm.; Praia Morro Peixe, 1 spm.; Praia

das Conchas, 2 spm. ; Praia Emilia, several spm., all between and under rocks at low tide, leg. Gofas,

XI. 1983; Punta Diego Vaz, 0,6 m, 3 spm. ; Ilheu das Cabras, 1 sh., off Pta. Diogo Nunes, 4 m, 1 spm. ; off

Praia Lagarto, 5-6m, 4 spm., 5 juv. v., all R/V “Calypso”, leg. Marche-Marchad, 6-11.VI. 1956; all

MNHN. Annobon : 1°24' S/5°37,5' E, 20-40 m, 2 spm., leg. Crosnier, 11.XII. 1965; 1°24' S/5°36,7' E, 10 m,

1 spm.; 1°25,2'S/5°36,l'E, 20 m, rocks with calcareous algae, 2 spm., both dredged R/V “Calypso”, leg.

- 315 -

Marche-Marchad, 13.VI.1956; all MNHN. Gabon : off Port-Gentil, on oil platform anchor, 30m,

1 spm., leg. Chevalier, 1987 ; Port-Gentil, 2 spm., coll. Office Pte-Noire, both MNHN. R.P. Congo :

Pointe-Noire, Plage Mondaine, on beach. 1 v., leg. von Cosel, XII. 1985, MNHN. Angola : Cabo Ledo,

Luanda province, 10-40m, 1 sh.; Caotinha, Benguela province, 10 spm., 1 sh. ; Baia Azul, Benguela

province, rocks at low tide, 4 spm., 1 sh. ; Baia do Limagem, Benguela province, rocks, 0-2m, 1 spm.;

Baia de Santa Maria, Benguela province, rocks 0-2 m, 3 spm., 1 v. ; Baia da Lucira (Bissonga),

Moçâmedes province, rocks at low tide, 1 spm. ; Lucira (Praia do Cesar), Moçâmedes province, 3 spm. ;

Chapeu Armado, Moçâmedes province, rocks at low tide, 5 spm. ; Praia Amelia, Moçâmedes province,

rocks at low tide, 3 spm., all leg. Gofas, 1982-85; all MNHN.

Biotope : Byssally attached to rocks, stones, shells and other hard objects, from low tide about 40 m.

Remarks

This species despite its variability should not be confused with other west African species

of Barbatia as it is the only species with the distinctive well spaced concentric ridges which give

the periostracum a frilled appearance. It is also the only species to be encountered in the rocky

lower intertidal and sublittoral.

We investigated the possibility that as in the Indo-Pacific there might be two closely

related species equivalent to B. foliata (Forsskâl, 1775) and B. decussata (Sowerby, 1833).

Despite the variability in form of the west African specimens we could find no indication of

pattern except that crevice dwelling examples were usually fore shortened or distorted.

Barbatia complanata belongs to the group of species represented by B. Candida (Helbling,

1779) in the Caribbean, by B. foliata (Forsskâl, 1775) in the Indo-Pacific and by B. reeveana

(d'Orbigny, 1846) in the Panamic province. The west African species differs in having a much

finer sculpture with approximately twice as many anterior and median primary riblets and in

the posterior riblets narrower, more regular and numbering from 6-7 rather than the 3-4

typical of the Caribbean species. The periostracum of B. Candida is heavier and the emergent

bristles are consequently much longer and more robust. The Indo-Pacific B. foliata is an

altogether much larger species with a more coarse sculpture which lacks the regular, well

spaced concentric ridges. The west African species is therefore closer to that of the Caribbean.

American authors place these species in the subgenus Cucullearca Conrad, 1865. These

species are distinct from those of Barbatia sensu stricto such as B. barbata and B. gabonensis

(see below) but we are not certain of the affinities with other, mainly Indo-Pacific, groups and

refrain from using this taxon until a more thorough revision is completed.

Barbatia gabonensis n. sp.

(PI. Ill, 6A-B ; fig. 14; map 5)

Type material : Holotype (27.7 mm), MNHN, off Mayumba, Gabon, 3°25' S/9°56' E, 100 m, trawled

R/V “Thierry”, Guinean Trawling Survey, Sta. 58/6, 30.XI. 1963. Paratypes : NMWZ, Ilha de Luanda,

Angola, 90m, 1 spm., leg. Gofas; MNHN, off Grand Bassam, Côte d’Ivoire, 5°00'N/3°23'W 100m,

1 spm., trawled R/V “ La Rafale ”, Guinean Trawling Survey, Sta. 26/6.

Type locality : Mayumba, Gabon.

— 316 —

Fig. 12. — Internal views of right valves of Barbatia complanata (Bruguière) : A, Côte d’Ivoire; B. Angola. (Scale

bar = 10 mm.)

Description

Shell to 30 mm in length, not very thick for the genus. Equivalve, not inflated.

Inequilateral, beaks in the anterior quarter.

Outline roughly rectangular, longer than high, length : height ratio from 2.2-2.6 : 1, dorsal

and ventral margins more or less parallel. Posterior area indistinct; posterior angle smoothly

rounded; posterior margin oblique, gently curving to posterior ventral junction which is

narrowly rounded or subacute. Median area flattened or weakly depressed ; byssal gape very

narrow, short ; ventral margin gently curved to straight, byssal sinus if present, weak. Anterior

margin in smaller shells broadly rounded; later becoming more straight, oblique with a

narrowly rounded anterior ventral junction. Dorsal margin moderately long, more or less

straight.

Dorsal area very narrow, cleft; umbonal separation slight. Ligament restricted to area

between and behind the beaks, chevrons narrow, numbering up to 7.

Hinge plate moderately thick, teeth in two series which are barely separable but the

junction lies below the beaks, anterior set up to 10 teeth, posterior set up to 16 teeth. Teeth

serrated, straight or slightly chevron shaped, becoming a little oblique towards the margins of

the plate.

Sculpture fine of nodulose radial riblets, 90-110 in number more or less uniform in size

with the exception 13-18 pairs of larger riblets which border distinct radial grooves.

Periostracum mostly lamellar except for long, subtubular, semispathulate bristles arising

from the radial grooves. Lamellae straw coloured, bristles dark brown.

Shell mostly white, some with faint tinges of brown or brownish pink colour.

Adductor scars subequal, the posterior a little longer, posterior pedal/byssal retractor

long and very narrow.

— 317

Selected shell measurements

Length

(mm)

Height

(mm)

Tumidity

(mm)

margin to beak

(mm)

Rib No.

Groove No.

26.9

16.1

12.1

8.3

29.9

16.9

13.5

7.6

105

22.0

11.8

8.7

5,6

100

23.5

13.2

10.2

6.4

26.2

15.6

10.7

7.7

108

21.5

15.6

8.4

5.9

109

Distribution : Barbalia gabonensis is an entirely tropical species with a restricted distribution from

Liberia south to northern Angola.

L/H UT LVA-Bk

Fig. 13. — Box plots of the ratios of Total Shell Length to Height (L/H), Tumidity (L/T) and Anterior to Beak

Length (L/A-Bk) of Barbatia gabonensis from West Africa.

Material examined : The type material; Liberia : 4°37'N/10°50' W, 90-100m, 2 v., dredged R/V

“Calypso”, leg. Marche-Marchad, 24.V.1956, MNHN. R.P. Congo : off Pointe-Noire (no precise

locality), 1 spm., leg. Marche-Marchad, MNHN.

Biotope : Barbatia gabonensis is a deep water form with the present data indicating a range around

100 m. The byssus is functional although small and this suggests that this species lives attached to rock,

stones or other hard substrates. The byssus is much weaker than in related forms from the littoral and

sublittoral zones further suggesting that the local conditions are tranquil or sheltered. This could be

explained by the lack of wave action at the depths from which B. gabonensis has been recovered.

Derivatio nominis : gabonensis from Gabon, the country where the type locality is situated.

Remarks : The immediate distinctive feature of this species is the series of radial grooves

and the long periostracal bristles arising from them. This distinguishes it from the Barbatia

— 318

Map 5. — Distribution of Barbatia gabonensis (circles) and B. ionthaclos (triangles).

candida-complanata-foliata complex in which the bristles are not differentiated. Some species

have differentiated bristles but none so marked or in such widely separated rows as B.

gabonensis. Barbatia sculpturata Turton, 1932 is also much smaller and has only a few broad

ribs on the posterior area, it is restricted to the sublittoral zone of the coasts of Natal and Cape

Province (S. Africa) (Kilburn, 1983). Barbatia barbata (Linné, 1758) from the Mediterranean

has a similar bristle pattern when small but later there is much less distinction between the

primary and secondary bristles and in the largest specimens the whole of the dorsal area is

thatched. Furthermore in B. barbata the ligament fills the whole of the dorsal area. Barbatia

pistacia (Lamarck, 1819) from south eastern Australia has a similar rib pattern but the bristles

are poorly differentiated and the rows of larger bristles are much more numerous.

Barbatia ionthados n. sp.

(PI. Ill, 7A-B; fig. 15; map 5)

Type material : Holotype (20.6 mm), MNHN, South of Bassam, Côte d’Ivoire, 200 m, leg. Marche-

Marchad, 13.X.1960. Paratypes : MNHN, off Cape three Points, Ghana, 4°43,5'N/2°45,5'W, 100m,

1 spm., trawled R/V "La Rafale”, Guinean Trawling Survey II, Sta. 27/6, 20.III.1964; NMWZ, as

previous, 1 spm.

Type locality : South of Bassam, Côte d’Ivoire.

Fig. 14-15. — 14 : Internal view of right valve of Barbalia gabonensis n. sp. Gabon. 15 : Internal view of right valve of

Barbatia ionthados n. sp. Côte d’Ivoire. (Scales bars = 5 mm.)

Description

Shell to 21 mm in length, very fragile. Equivalve. A little compressed. Very inequilateral,

beaks in the anterior fifth.

Outline elongate rectangular, length to height ratio 2.6-2.7 : 1, dorsal and ventral margins

more or less parallel. Posterior area not expanded but rather long, posterior angle rounded but

distinct, posterior margin oblique to broadly rounded, posterior ventral junction rounded.

Median area lacking sinus, ventral margin more or less straight, byssal gape minute. Anterior

margin broadly rounded. Dorsal margin long, more or less straight.

Dorsal area very narrow, slightly cleft, umbonal separation slight. Ligament situated

entirely behind the beaks, chevrons narrow numbering up to 4.

Hinge plate long, narrow; teeth in two series, separated by a very small gap at a point

below the beaks; anterior set up to 9 teeth, posterior set up to 31 teeth. Teeth small, more or

less straight, finely serrated; central teeth more or less vertical, lateral teeth slightly oblique.

Sculpture very fine, of weakly nodulose radial riblets, 88-96 in number but those on the

anterior margin are difficult to distinguish and some shells may have more riblets. The riblets

show no pattern except that they become progressively finer towards the anterior.

Periostracum of long very fine dark straw coloured suberect bristles which are longest on

the posterior angle and most erect on the posterior slope. There is no trace of inter bristle

lamellae.

Shell uniformly white.

Inner margin weakly serrate corresponding to radial riblets. Adductor scars subequal,

posterior pedal/byssus retractor narrowly elongate. Byssus a thin narrow strap.

Selected shell measurements

Length

(mm)

Fleight

(mm)

Tumidity

(mm)

margin to beak

(mm)

Rib No.

20.6

9.7

7.5

4.0

19.1

9.3

7.3

3.8

11.1

5.6

4.2

2.1

Distribution : Living specimens have been taken only off the northern coast of the Gulf of Guinea.

A number of worn valves from off Senegal suggests a wider distribution and one might expect this species

to occur throughout tropical West Africa.

Material examined : The type material ; Senegal : off Gorée, 80 m, 8 v., poorly preserved, dredged

R/V "Gérard Tréca”, leg. Marche-Marchad, 20.11.1956, MNHN.

Biotope : From the limited material available B. ionthados is apparently a deep water species living

from 100-200 m. The functional byssus and general shell form suggest that it is epibyssate living attached

to hard substrates. As with its Indo-Pacific counterpart Barbatia tenella Reeve, 1844 it may live in crevices

or under stones where there is shelter but in the deep waters preferred by B. ionthados such protection

may not be required.

Dériva tio nominis : ionthados , Greek, “long haired” or “shaggy”, referring to the form of the

periostracum.

Remarks : Only one other species resembles B. ionthados , that is B. tenella Reeve, from

the Indo-Pacific which shares the fragile shell, posterior ligament, fine sculpture and an entirely

spicate periostracum. Dall, Bartsch and Rehder (1938) erected the genus Barbarca and

Iredale (1939) the genus Opularca , for species close to this form. As they are clearly linked to

Barbatia they would only warrant subgeneric status of which the earliest name is Barbarca.

Barbatia legumen (Lamy, 1907)

(PI. Ill, 8, 9A-B, 10; fig. 16-18; map 6)

Area legumen Lamy, 1907 : 74-76, pi. 1, fig. 3-4.

Type material : MNFIN, 16 syntypes from three different localities : 5 spm. Gabon, coll. Dibowsky,

1893; 5 spm., no locality, coll. Largentière, 1887; 2 spm., 4 v., “Bata Congo” (= Bata in Equatorial

Guinea), coll. Pobeguin, 1891. Among the latter lot is the specimen figured by Lamy (1907) and this is

here selected as the lectotype.

Type locality : Bata, Equatorial Guinea. On the original label of the Pobeguin collection this

locality is always cited as “ Bata Congo ”, at that time it belonged to the French Congo and did not

become Spanish until 1900.

— 321 —

Description

Shell to 52 mm in length. Equivalve. Compressed. Inequilateral, beaks in the anterior

third.

Outline of adult submytiliform, often arcuate, anterior part narrow, posterior part

expanded. Posterior area small; posterior angle broad, rounded and forming greater part of

the posterior half of the shell ; posterior margin long, oblique, sloping steeply, dorsal auricule

indistinct or lacking. Median area distinctly sinuate, ventral margin long, arcuate. Anterior

area small, demarcated by a rounded anterior angle; anterior margin narrowly rounded.

Dorsal margin moderately long, straight. Outline of juveniles similar but posterior margin

shorter and distinctly auriculate, ventral margin less arcuate and anterior area larger but

anterior angle indistinct. The increasing arcuate development with age is illustrated in

figure 17.

Dorsal area very narrow, deeply cleft ; umbonal separation slight, ligament barely visible

in joined valves. Ligament filling the whole of the dorsal area including the anterior part;

ligament almost entirely lamellar, chevrons very strong numbering up to 5.

Hinge plate moderately thick ; teeth probably in two series but the central teeth are

usually worn giving the appearance of distinct anterior and posterior sets. When well preserved

up to 50 teeth in all. Teeth slightly chevron shaped, finely serrated, becoming oblique laterally.

Sculpture of very numerous radial riblets, usually worn but best preserved in median

sinus.

Periostracum initially with broad appressed bristles on posterior angle but later consisting

primarily of thick concentric lamellar layers with scarcely emergent bristles. Colour a deep

tanned dark brown.

Shell external colour white to cream, internally bluish in juveniles white in adults.

Adductor muscle scars unequal, the posterior twice the size of the anterior. Posterior

pedal/byssus retractor small, narrowly oval.

Selected shell measurements : See figure 16.

Distribution : Barbatia legumen occurs only in the southern part of tropical West Africa, from

Equatorial Guinea to southern Angola (Santo Antonio). The greater part of this range lies within the

influence of the cold Benguela Current which in the southern winter can reach the coast of Gabon. Here

and in Equatorial Guinea it seems to be very rare.

Material examined : The type material ; R.P. Congo : Pointe Indienne, rocky shore 1 sh. ; Pointe-

Noire, Plage Sauvage, on beach, 3 v. ; Plage Mondaine, on beach, numerous sh. and v. ; off Plage

ORSTOM, 3-7 m, numerous sh. and v., all leg. von Cosel, XI-XII.1985; several sh. and v., leg. Crosnier

(Office Pte.-Noire); all MNHN. Angola : 10km S of Ambrizete, Zaire province, intertidal, on beach,

many fresh sh. and v. ; Barra do Dande, Bengo province, between rocks at low tide, 2 spm. ; Baia Sào

Tiago, Bengo province, between rocks at low tide, 4 spm. ; Cacuaco, Bengo province, between rocks, 0-

1 m, 14 spm. ; Corimba, Luanda province, Praia Etambar, between rocks at low tide, 5 spm., 1 sh. ; Cabo

Ledo, Luanda province, 10m, 11 juv. spm., 3 juv. sh. ; Santo Antonio, Benguela province, between rocks

at low tide, 1 spm. ; Baia das Pipas, Moçâmedes province, on rock platform, 1 juv. spm. ; Porto

Alexandre, Moçâmedes province, 2m, 1 juv. v., all leg. Gofas, 1982-85; all MNHN.

Biotope : This species lives byssally attached to rocks, on the undersides of stones and to secondary

hard substrates on soft sediments. The bathymetric range is from the intertidal to l-2m in the sublittoral.

— 322

Fig. 16-17. — 16 : Box plots of the ratios of Total Shell Length to Height (L/H), Posterior Height (L/PH), Tumidity

(L/T) and Anterior to Beak Length (L/A-Bk) of Barbatia legumen from West Africa. 17 : Graph of the ratio Total

Shell Length : Difference in Median and Anterior Height plotted against Total Shell Length on log axis, showing

the increasing arcuate form of the shell with age in Barbatia legumen.

Remarks

Barbatia legumen belongs to a group of species which are submytiliform in shape and are

typical inhabitants of the littoral and shallow sublittoral throughout the Indo-Pacific. The

most widespread of these related species are B. obliquât a (Gray, 1837) [Indian Ocean] and B.

virescens (Reeve, 1844) [Indo-West Pacific]. B. obliquata is more expanded posteriorly, not

auriculate and the ligament is restricted to behind the beaks. B. virescens can be auriculate and

the ligament is on both sides of the beaks but the outline is much shorter, the sculpture more

pronounced and the periostracum more spicate.

Some submytiliform species have been given generic rank; Savignyarca Jousseaume, 1898

(type S. savignyarca = Barbatia obliquata) ; Obliquarca Sacco, 1898 (type, Area modiliformis

Deshayes, 1831) and Barbatirus Iredale, 1939 (type B. minulus Iredale, 1939). Habe (1977)

regards these as synonyms of Savignyarca but this presupposes that the submytiliform species

have a common ancestry. We do not regard the common adaptive form as sufficient evidence

to conclude monophyly because the incidence of convergent radiations within the Arcoidea is

- 323 -

well documented (Stanley, 1972). In recent forms the convergent radiations within the

Arcidae and Noetiidae illustrate the point.

Fig. 18. — Internal view of right valve of Barbatia legumen Lamy. Angola. (Scale bar = I Omm.)

Subgenus NIPPONARCA Habe, 1951

It has not been our intention to introduce subgenera within Barbatia but in this case we

have both anatomical and shell characters which allow us to confirm that Nipponarca is a

useful division.

Type species : Area bistrigata Dunker, 1858 : 87, pi. 30, fig. 4, see also Habe, 1951, fig. 49.

Revised diagnosis : Shells to 50 mm. Equivalve. A little compressed. Inequilateral, beaks in the

anterior third. Outline subrectangular, distinctly longer than high, dorsal and ventral margins subparallel.

Hinge plate long, straight, teeth small. Dorsal area flat or almost so. Sculpture of few radial ribs;

posterior ribs rather broad, flat and weakly sculptured ; median ribs bifurcate, nodulose. Periostracum

with long semi-erect bristles arising from the interspaces of the posterior angle. Labial palps very large

with numerous sorting ridges. Byssate species inhabiting inshore areas where the conditions are turbid

and often under estuarine influences.

Species included : Barbatia (Nipponarca ) bistrigata (Dunker, 1858) [Indo-Pacific, Pakistan to

Japan], Barbatia ( Nipponarca ) allocostata this paper [tropical west Africa, Senegal to Sierra Leone].

Probably Barbatia signala (Dunker, 1858) [Indo-Pacific, India to China],

Barbatia (Nipponarca) allocostata n. sp.

(PI. IV, 1A-B, 2; fig. 19, 20; map 6)

Type material : Holotype (28.4 mm), MNHN, Mouth of Rio Geba, Guinea-Bissau,

11°57,5' N/16°27' W, 7 m, agglomerations of live and dead Crassostrea gasar, on oyster shells, trawled R/V

“André Nizery”, leg. von Cosel, 9.X.1988. Paratypes as holotype; MNHN, 9 spm.; NMWZ, 1990.017,

5 spm.

Type locality : Mouth of Rio Geba, 11°57,5'N/16°27'W, Guinea-Bissau.

- 324 -

Description

Shell to 35 mm in length. Equivalve. A little compressed, most inflated across the anterior

umbonal region and narrowing posteriorly. Inequilateral, beaks in the anterior third.

Outline subrectangular, much longer than high. Posterior area long, weakly demarcated,

posterior angle rounded and becoming obsolete ; posterior margin initially rounded, more or

less vertical becoming oblique and some auriculate; posterior ventral junction rounded.

Median area sulcate, ventral margin more or less straight, usually indented at byssal gape

which is relatively short and narrow. Anterior area short, demarcated by weak anterior ridge ;

anterior margin broadly rounded. Dorsal margin long, straight.

Fic. 19-20. — 19 : Barbatia (Nipponarca) allocoslata n. sp. A, internal view of right valve; B, external view of left

valve with periostracum removed. Guinea-Bissau. 20 : Size series of dorsal views of Barbatia ( Nipponarca)

allocostata n. sp. Guinea-Bissau. (Scales bars = 5 mm.)

Dorsal area narrow, weakly cleft to flat, umbos well separated. Ligament initially behind

the beaks but developing anteriorly in larger specimens; chevrons few, numbering up to 3.

Hinge plate narrow, teeth in two series but separation is indistinct, total number 50. Teeth

small, weakly serrated, more or less straight, vertical centrally becoming a little oblique

laterally.

- 325

Sculpture of relatively few, 26-28, radial ribs. Posterior 10-12 ribs broad, flat, more or less

smooth ; median ribs deeply bifurcate, nodulose ; anterior ribs simple, irregularly nodulose.

Periostracum of very long semierect bristles arising from the rib interspaces over the

posterior angle, elsewhere the pattern is the same but the bristles are much shorter and fragile.

Bristles dark brown, remainder paler.

Shell mostly white but externally umbos grey and some with brown blotches on the

posterior area; internally the umbonal cavity is suffused with green or greyish green tints.

Adductor muscle scars unequal, the posterior half as big again as anterior scar. Posterior

pedal/byssus retractor scar narrowly elongate.

Anatomy (the following account is based on preserved specimens only)

The mantle edge (fig. 21) is entirely unfused and thickened posteriorly where it is thrown

into small folds. Pigmentation is weak with only a few brown patches on the exterior of the

outer fold in the posterior ventral region. Eyespots are absent but there is a single anterior

dorsal pigment spot.

The gills (fig. 21) are typically arcoid and the gill axis is contorted suggesting that it is

muscular and capable of extending the gills to the margin of the shell. The labial palps (fig. 21)

are very large, semicircular in outline and with about 90 sorting ridges. These palps are very

large for the genus, most being narrow with about 15-20 ridges.

Fig. 21. — Gross anatomy of Barbatia (Nipponarca) allocostata n. sp. viewed from the left side after removal of the

left valve and mantle. (Scale bar = 5 mm.)

AA, anterior adductor muscle ; B, byssus ; CT, ctenidium ; F, foot ; LP, labial palps ; ME, folded mantle edge ;

MEP, mantle edge pigmentation; PA, posterior adductor muscle; PPR, posterior pedal retractor muscle.

The gut is typical of the genus with a short oesophagus entering the stomach on its

anterior dorsal face ; the mid gut exits from the ventral floor of the stomach and passes deeply

into the foot where it is weakly folded before forming a large anterior loop, then it passes

dorsally across the right hand side of the stomach before bending posteriorly as the hind gut.

The anterior loop is more prominent than in other species of Barbatia. The stomach is

typically arcoid but the food sorting area is restricted to the anterior dorsal food sorting

caecum which is endowed with prominent sorting ridges. The right and anterior ventral

— 326 —

embayments have openings to the digestive diverticula and ridges are restricted to the rejection

tract which follows the major typhlosole.

The foot (fig. 21) is large with a well developed heel and toe. The byssus groove is

centrally placed and produces a relatively large but narrow sheet byssus (fig. 21) typical of the

genus. The size of the byssus is reflected in the large posterior pedal/byssus retractor muscles

which are narrowly elongate in section.

The anatomy of this species is similar in most ways to that of Barbatia as a whole in that

it reflects an epibyssate habit. Significantly different is the size of the labial palps which are

more typical of infaunal forms such as some Anadara species (Heath, 1941 and Lim, 1966) and

a new genus to be described in Part two of this revision. The biotope described below does

appear to be one where resuspended matter is dense and this would explain the adaptive value

of this epibyssate species having a large sorting capacity. A little surprisingly are the

apparently weak mantle edge folds, these are usually more developed in species which inhabit

muddy biotopes. The lack of pigmentation and eyespots on the mantle edge are not

characteristics of Barbatia but again can be explained if the water column is so full of

suspended matter that light is virtually excluded.

Selected shell measurements : See figure 22.

Distribution : This species seems to have a limited distribution to the northern part of tropical West

Africa. It is actually known from the extreme south of Senegal (southern Casamance) to the border

between Guinea and Sierra Leone. Most probably it goes further south into Sierra Leone but we have

never seen material from south of 9°N.

Fig. 22. — Box plots of the ratios of Total Shell Length to Height (L/H), Tumidity (L/T) and Anterior to Beak

Length (L/A-Bk) of Barbatia ( Nipponarca ) allocostata from West Africa.

Material examined : The type material; Senegal : Karabane Bôlon, Casamance, off Karabane, 4m,

7 v. ; Casamance, creek off Elinkine, 3 m. 3 v. ; Ourong Bôlon, S-Casamance, 2-4 m, 2 v. ; Cap Skirring-

Diembéring, on beach, 1 v. ; Essoukoudiak Bôlon, on the frontier to Guinea-Bissau, 4-6 m, coarse sand

with pebbles, 1 spm., many v., all leg. von Cosel, 5-17.III.1988, all MNHN. Guinea-Bissau : Mouth of

Rio Geba, H 0 57,5'N/16 0 27'W, 7m, on oysters (from type lot), 48 associated spm., MNHN. Guinea :

Kaporo, NW coast of Conakry Peninsula, in front of ORSTOM, low tide, undersides of rocks, 1 spm.;

Kaporo Port, Conakry Peninsula, rocks at low tide, 1 v. ; Dixinn Port, NW coast of Conakry Peninsula,

gravel, low tide, 1 v. ; Conakry, Corniche Sud, in front of the “ People’s Palace ”, rocks at low tide, 4 v. ;

Kassa, Iles de Los, E-side, N of village, on the underside of a stone at low tide, 1 spm., all leg. von Cosel,

V and XI.1988, all MNHN.

327

Map 6. — Distribution of Barbatia legumen (circles) and B . allocostata (triangles).

Biotope : Barbatia ( Nipponarca ) allocostata occurs on hard bottoms such as stones and rocks and is

byssally attached. It is frequently found on offshore oyster beds consisting of Crassostrea gasar

(Dautzenberg, 1891) where it is attached in crevices and between oyster shells. In Guinea-Bissau it was

taken in trawls from sandy bottoms where it was found on shells of living Cymbium pepo (Lightfoot,

1786) which were also covered by small oysters. It was likewise found on living or hermit crab inhabited

shells of Pugilina morio (L., 1858) and even on oyster covered valves of large bivalves like Macoma

cancellata (Sowerby, 1873) and Mactra rostrata Spengler, 1802. B. allocostata seems to be limited to

murky, sediment and seston laden water in regions with estuarine influences and seasonal salinity changes.

On the rocky shores of the Conakry peninsula it was found on the sides and undersides of stones at low

tide and is a rare but regular member of the Crassostrea gasar community. B. allocostata is not common

in the intertidal and is most frequently found offshore to about 15 m.

Derivatio nominis : allocostata , Greek, compounded from allasso meaning “ to change ” and

costatus meaning “to bear ribs”. This refers to the abrupt change in the form of the radial ribs from the

median to posterior areas.

Remarks : Barbatia ( Nipponarca) allocostata is very closely allied to B. (N.) bistrigata

(Dunker, 1858). The latter species is heavier shelled, reaches a larger size, the marginal

crenulations are stronger, the anterior most, posterior ribs develop up to 4 ridges which do not

bisect the rib and the posterior angle periostracal bristles are shorter and more stout.

- 328 -

Genus BENTHARCA Thiele, 1931

Type species : Area nodulosa Miiller, 1776.

Bentharca asperula (Dali, 1881)

(PI. VIII, 6A-B ; fig. 23)

Macrodon asperula Dali, 1881 : 120-121.

Area profundicola Verril & Smith in Verrill, 1885 : 439-440, pi. 44, fig. 23-23a.

Area ( Barbatia ) pteroessa Smith, 1885 : 844.

Type material : In USNM.

Type locality : Off S. E. United States, “Blake” sta. 33, 2875m.

Description

Shell to 12 mm in length. Equivalve. Somewhat compressed. Inequilateral, beaks in the

anterior quarter.

Outline subtrapezoidal. Anterior area greatly restricted, posterior roundly expanded

giving an overall wedge-shaped appearance. Posterior margin broadly rounded ; ventral

margin sloping to narrow anterior margin, the latter slightly indented by byssal sinus. Median

byssal sinus present at all sizes but byssal gape indistinct. Dorsal margin long and straight.

Dorsal area long, narrow initially but expanding rapidly with age. Ligament restricted to

the posterior area but filling area between beaks with maturity.

Hinge plate very narrow; teeth in two series, separated by a wide edentulous gap. Teeth

numbering up to five in each set ; posterior teeth becoming subparallel to dorsal margin.

Sculpture very weak, of faint radial striae only. In other regions the sculpture can be a

little stronger with faint raised riblets.

Periostracum usually worn and preserved at margins only; of very slender appressed

bristles.

Colour white, periostracum a dirty olive brown.

Adductor muscle scars indistinct but unequal, the posterior about twice the size of the

anterior. Byssus retractor muscle small, reflecting the weak byssus which consists of a single

narrow strap.

Distribution : A cosmopolitan species restricted to the abyssal zone from 2000-5000 m.

Material examined : Based on the data in Oliver and Allen (1980).

Biotope : Bentharca asperula lives attached to small stones, gravel and grit particles.

Remarks : Two species of Bentharca occur in the Atlantic Ocean but the second B.

nodulosa (Müller, 1776) has not yet been recorded from tropical West Africa. B. nodulosa lives

329

at shallow depths in the subarctic region and undergoes increasing submersion towards the

south of its range reaching 3000 m off Madeira. It is a larger shell with a more coarse sculpture

resembling that of the genus A car.

Fig. 23. — Internal view of right valve and dorsal view of Bentharea asperula (Dali). Angola, 3975 m. (Scale bar =

2 mm.)

Subfamily Anadarinae

Genus ANADARA Gray, 1847

Type species : Area antiquata Linné, 1758 (OD).

Diagnosis : The generic systematics of most of the Anadarinae is presently confusing, especially

concerning the distinction between Anadara, Scapharca and Cunearca. The distinctions as detailed by

Newell in Moore (1969) rest on the form of the ligament and on the equality of size of right and left

valves. The ligament is referred to as amphidetic or opisthodetic, however in many species the ligament

initially develops behind the beaks and eventually grows to fill the whole of the dorsal area. The degree of

overlap of the right valve also has an ontogenetic relationship as well as being variable between species of

obvious similarity in general form. These characters therefore are unreliable when used in isolation and

Newell’s definitions are consequently too broad. Other genera and subgenera have been revived or

introduced mainly by Olsson (1961) for panamic forms and by Iredale (1939) for Australian forms.

Olsson (1961) uses a wider range of characters yet there is still reliance on some that do have ontogenetic

changes and he does not compare his subgenera with those from the Indo-Pacific. Consequently a few

divisions appear to be stable such as Rasia Gray, 1857 ; Larkinia Reinhart, 1935 and Caloosarca Olsson,

1961. In other cases such as Olsson’s (1961) use of Diluvarca Woodring, 1925 there remains a wide

interpretation with some overlap into Anadara and Scapharca forms.

Our conclusion is to use Anadara as a broad generic group with subgeneric designations

reserved for those cases where there is a clear resemblance in overall form to the type species of

the subgenus concerned. There is clearly the need for a revised generic systematics on a world

wide scale but this is beyond the scope of this paper and we refrain from introducing revised

concepts in isolation.

— 330 —

Anadara geissei (Dunker, 1891)

(PI. IV, 3A-B, 4A-B, 5, 6A-B; fig. 24; map 7)

Area setigera Dunker, 1853 : 45, pi. 9, figs. 16-18 (non Reeve, 1844).

Area ( Anomalocardia ) dunkeri Kobelt, 1891 : 162, pi. 41. figs. 2-4.

Area (Anomalocardia ) geissei Dunker in Kobelt, 1891 : 163-164, pi. 41, figs. 5-6.

Type material : In SMF Frankfurt.

Type locality : Senegal.

Description

Shell to 75 mm in length. Slightly inequivalve in juveniles but adults more or less

equivalve. Not inflated, tumidity approximately 1/2 to 1/3 of the length. Inequilateral, beaks in

the anterior third.

Fig. 24. — Internal view of right valve of Anadara geissei (Dunker). Angola. (Scale bar = 10mm.)

Outline oblong, subrectangular, distinctly longer than high, juveniles distinctly expanded

posteriorly, adults symmetrical. Posterior area indistinct; posterior angle marked in juveniles

but becoming obsolete early in ontogeny ; posterior margin obliquely subtruncate and slightly

auriculate in juveniles, becoming simply subtruncate and finally rounded but more acute than

anterior margin. Median area initially weakly sulcate, this noticeable to about 30 mm, then

becoming progressively obsolete; ventral margin rather long and more or less straight, larger

examples with a narrow anterior ventral byssus gape. Anterior margin broadly rounded.

Dorsal margin rather long, straight.

— 331 -

Dorsal area long, rather narrow except in the largest specimens, umbonal separation

moderate. Ligament initially opisthodetic but developing anteriorly at about 6 mm, apparently

amphidetic by 15 mm and remaining with a single lateral chevron bordering a large fibrous

sheet until about 40 mm when new chevrons are added these totalling 4-5 in the largest

specimens.

Hinge plate rather narrow to moderate depending on the degree of encroachment by the

ligament ; teeth in two series, separation distinct, anterior set up to 30 teeth, posterior set up to

35 teeth. Teeth small, median series more or less straight and vertical ; lateral series slightly

chevron shaped, slightly oblique.

Sculpture of 29-32 radial ribs of which up to 18 anteriorly become progressively bifurcate,

posterior ribs wider and more flat, anterior ribs very weakly ridged by low closely spaced cross

bars.

Periostracum a thick coating of appressed laminae with bristles developing from the

primary interspaces and from the bifurcate interspaces ; anterior and median bristles short,

lanceolate and soft, posterior bristles coarse, long, rigid, semi-erect; colour a deep reddish

brown except for posterior bristles which are black ; juveniles have a distinctive maculate

pattern over the posterior area formed by differential thickening of the periostracum.

24 26 28 30 32 34 36 38 40

26 Rib Number

Fig. 25-26. — 25 : Box plots of the ratios of Total Shell Length to Heigth (L/H), Tumidity (L/T) and Anterior to Beak

Length (L/A-Bk) of Anadara geissei from West Africa (n = 27). 26 : Bar chart of Rib Number for 22 shells of

Anadara geissei.

— 332 -

Shell white.

Adductor scars subequal, the posterior a little larger; posterior pedal/byssal retractor

elongate oval. Inner margin deeply crenulate.

Selected shell measurements : See figure 25.

Distribution : This species ranges from the Cape Verde Islands and Mauritania (Cap Blanc) to

southern Angola (Benguela).

Material examined : Mauritania : Off Port Étienne, 20°20'N/16°22' W, 10m, 3 v., coll. Marche-

Marchad, 8.V.1965, MNHN. Cape Verde Islands : Sta. Lucia, 52 m, 1 spm. + 1 v., dredged R/V

“Princess Alice” (sta. 1152), coll. H. Fischer, 1901; off Boa Vista, 15m, 1 spm., dredged R/V

“Calypso", 1959 ; SW of Boa Vista, 30 m, 2 v., 23. X. 1948 ; Sâo Vicente, Baia Porto Grande, beach, 11 v.,

leg. von Cosel, 19.XII.1978 ; Sâo Vicente, Mindelo, beach, 3 v„ leg. von Cosel, 17.XII.1978; all MNHN.

Senegal : No precise locality, 1 spm., coll. Vayssière; Rufisque, 18-20m, many spm.; Pte. Cansado, 2 v.;

W of Cap Rouge, 6 v., all coll. Mission Gruvel, IV. 1909; Gorée, 1 spm., coll. Bavay; Gorée, 1 spm.,

coll. Geret; Cap Vert, 1 v., coll. Maury; off Dakar, 50m, 4 v. ; Banc de Seminole, 43-45m, 1 v. ; off

Gorée, 95-98m, many v., all dredged R/V “Gérard Tréca”, leg. Marche-Marchad, 1954-1956; Dakar,

Anse Bernard, 1 spm., leg. Marche-Marchad; SE of Gorée, 14°41'N/17°23,2'W, 17m, fine sand and

mud, many v., dredged R/V “Louis Sauger”, leg. von Cosel, III. 1988; M’Bour, Petite Côte, on beach,

1 v., leg. von Cosel, 22.III. 1988; S. Casamance, Essoukoudiak Bôlon, 4-6 m, shelly sand, 1 v. ; Karabane

Bôlon, 3-4m, shelly sand, 1 v., both leg. von Cosel, III. 1988; N. Casamance, Abéné, 13°03'N/17°03'W,

20m, very fine sand, 1 v. ; Kafountine, 12°57,5'N/17°16,8'W, 35m, medium sand and rocks, 1 v. ;

12°56,9'N/17°06,8'W, 22m, fine sand. 3 v. ; 12°44,5'N/17°27,3'W, 40m, fine sand, 8 v. ;

12°32' N/17°28,8' W, 45 m, fine sand, 3 v. ; off Diembéring, 12°29,6' N/17°24,3' W, 35 m, fine sand, 1 v., all

dredged R/V “Louis Sauger”, leg. von Cosel, III. 1988, all MNHN. Guinea-Bissau : Ilhas Bissagos, 7 v.,

leg. Mission Gain, 1913, MNHN. Guinea: 10°30'N/15°43,5'W, 21m, 2 v. ; 10° 12' N/13°06' W, 20m,

2 spm.; 9°50' N/14°14'W, 15m, 2 spm. + 5 v. ; 9°30'N/13 o 53'W, 19m, 1 spm.; 9°18'N/13°45'W, 21 m,

1 spm.; 9°12'N/14°15,1'W, 33m, 1 spm.; 9°05,7'N/13°38' W, 24m, 1 spm.; all dredged R/V “André

Nizery”, leg. von Cosel, IV-V.1988; 9°25'N/13°48,5' W, 1 v., dredged R/V “Président Théodore

Tissier”; all MNHN. Sierra Leone: 7°15,5'N/12°51'W, 64m, 1 v„ dredged R/V “Calypso”, leg.

Marche-Marchad, 19.V.1956, MNHN. Nigeria : 4°00'N/6°l 1'E, 34m, 3 spm.; 4°03'N/6°12'E, 32m,

many v., both dredged R/V "Calypso”, leg. Marche-Marchad, 1956, both MNHN. Gabon :

0°14'S/9°14'E, 15-16m, 2v„ dredged R/V “Thierry”, Guinean Trawling Survey, leg. Cherbonnier,

16.XI.1963, MNHN. R.P. Congo: Pointe-Noire, off plage ORSTOM, 3-7 m, 1 spm., 1 v.; plage

ORSTOM, on beach, 1 v., plage Mondaine, on beach, 6 v., all leg. von Cosel, XI-XII.1985; all MNHN.

Angola : Baia de Corimba, Luanda province, 10-20m, many spm.; Cacuaco, Bengo province, 5-10m,

many spm.; Ponta das Lagostas, 5-20 m, 1 spm.; Santo Antonio, Benguela province, intertidal, 1 v., all

leg. Gofas, 1981-85, all MNHN.

Biotope : Anadara geissei inhabits fine and mixed sand with calcareous algae and shell debris. The

juveniles are byssally attached to hard objects. It is a subtidal species ranging from 3-30 m.

Remarks

This species was first described by Dunker in 1853 as Area setigera but that name is

preoccupied by Area setigera Reeve, 1844. Kobelt (1891 : 162) renamed this A. dunkeri but he

also then described (1891 : 163-164) A. geissei using a manuscript name from Dunker. The

two are undoubtedly synonymous, A. geissei representing a young specimen and A. dunkeri an

adult, but as the name A. geissei has been applied in all previous regional faunal studies we

have retained this name.

— 333 —

Guinea- L/H

Cape Verdes - L/H

Angola - L/H

Fig. 27. — Box plots for Length to Height ratios of three samples of Anadara geissei from Angola, Guinea and the

Cape Verde Islands.

Map 7. — Distribution of Anadara geissei.

Anadara geissei is not greatly variable throughout its range but the data displayed in

figure 27 shows that there is variation in the Length/Height ratio, with some examples from

the Cape Verde Islands being much higher and therefore more quadrate and in which the

posterior margin remains subauriculate. The choice of samples used suggests clinal variation

with latitude but it could also be ecophenotypic. The material and ecological data are limited

— 334

and at this time we consider all forms to be nothing more than individual varieties of A.

geissei. It should be noted that the unusual specimens approach the Caribbean A. notabilis

(Rôding, 1798), and Locard (1898) and Lamy (1907) record, in our view erroneously, this

species from Cape Verde Islands and Senegal.

We consider that A. geissei, A. floridana and the panamic species A.formosa (Sowerby,

1833) to be closely related and that the west African and Panamic species are most similar. The

subgenus Rasia Gray, 1857 is probably a useful taxon within the Atlantic/Panamic provinces

but we are not certain of its relationship with Indo-Pacific forms. A. geissei is a semi-infaunal

species forming extensive beds reminiscent of Modiolus and it is consequently rather different

from the truly infaunal burrowing forms of more typical Anadarinae. The type species of

Anadara, A. antiquata is similar in being much longer than high and one of us has (Oliver,

pers. obs.) noted that this species is also semi-infaunal although to a lesser degree. It is

therefore inappropriate at this time to make a decision on the value of the subgenus Rasia

world wide.

Anadara polii (Mayer, 1868)

(PI. V, 1-9; fig. 30; map 8)

Area antiquata Poli ( non Linné, 1758), 1795 : 146, pi. 25, figs. 14-15.

Area weinkauffi Crosse, 1862 : 324-325. Nomen dubium.

Area diluvii auct. (non Lamarck, 1819 : 45).

Area polii Mayer, 1868 : 75.

Area diluvii var. inflato-subglobosa Aradas and Benoit, 1870 : 80.

Area diluvii var. elongato-depressa Aradas and Benoit, 1870 : 80.

Area ( Anadara ) sphaerica Kobelt, 1891 : 53-54, pi. 15, figs. 3-4.

Area talismani Locard, 1898 : 308, pi. 8, figs. 21-24.

Area polii var. minor Locard, 1898 : 305.

Area polii var. ventricosa Locard, 1898 : 305.

Area polii var. cur ta Locard, 1898 : 306.

Area polii var. transversa Locard, 1898 : 306.

Area polii var. obliqua Locard, 1898 : 306.

Area polii var. angulosa Locard, 1898 : 306.

Type material : The type material of Area weinkauffi is uncertain : it was cited by Crosse as being in

the collection of Weinkauff, but later Weinkauff stated that it was never in his collection but was a

single specimen in the Algerian Museum which had been stolen and replaced by a monstrosity of Area

diluvii (Weinkauff, 1880 : 200). Given this uncertainty we regard A. weinkauffi as a nomen dubium.

Anadara polii was erected by Mayer in order to distinguish the recent Mediterranean species from

the Miocene A. diluvii Lamarck, 1819. His name was based on figures of the recent species in a number of

early publications of which the earliest is that of Poli, 1795. Consequently we regard the figure of A.

antiquata Linné in Poli to be the type.

The holotype of A. sphaerica is in SMF Frankfurt but it bears no locality data.

The type material of the varieties inflato-subglobosa and elongato-depressa are cited as in the

collection of Aradas and Benoit but its present location is not known.

The holotype of A. talismani is in MNHN and has a slightly broken hinge plate which has been

misrepresented in the original figure in Locard (1898).

Tyle locality : Sicily.

— 335 —

General description

We have encountered great difficulty in assessing the significance of the large range of

morphological variation seen within this taxon. Individual populations or samples show little

variation but between samples the extremes can be such that it is difficult to imagine that they

are part of a single taxon. More over there is no apparent pattern to this variation such that

we are unable to definitely invoke clinal, bathymetric or ecological causes to explain it. This

species is restricted to rather deep water and we have mostly small samples of live collected

material with the larger samples of dead valves only. This restricts our ability to assess the

distribution of the variants and also introduces the concern that some of the samples are of

subfossil origin, notably that of the large shells from Senegal.

In conclusion we have refrained from separating the morphs into nominal taxa and

instead we present a general diagnosis which highlights the common features and also

individual descriptions of the morphs. With further collection it may be possible to explain this

variation or even to conclude that this group is a complex of closely related species.

Shell to 55 mm in length. Rather heavy. Slightly inequivalve when small, more or

less equivalve in adult, LV a~ little larger. Inflated to greatly inflated, tumidity a little less

than or a little greater than height. Inequilateral, beaks in the anterior 1/4 to 1/5. Outline

oblong-subrectangular to suboval to ovate, usually longer than high but some only slightly

so. Length/Height ratio varying from 1 : 1 to 1.3 : 1 (fig. 28). Posterior area weakly defined

by rounded posterior angle; posterior margin oblique, curved to subtruncate. Median area

deeply sulcate in post larval shell, otherwise rounded; ventral margin gently to deeply

curved. Anterior area short to severely constricted. Length/Anterior to Beak Length varying

from 2.9-4.7 (fig. 28); anterior margin broadly rounded.

Dorsal area moderately wide to wide. Ligament initially opisthodetic, developing

anteriorly to fill dorsal area, chevrons widely spaced, few in number. Teeth numerous in two

series.

Sculpture of 24-28 (these include the small anterior and posterior dorsal riblets when

apparent) radial ribs (fig. 29), these rather narrow, high and equal to or narrower than

interspaces except down posterior angle where they may be wider. Rib sculpture discrepant ;

LY with closely spaced, rather small raised cross bars, RV similar but much weaker.

Periostracum reddish brown, with bristles in the interspaces, these are all rather soft and

fragile, anterior and median areas with short sharply pointed triangular bristles, posterior

angle with very long, narrow, linear bristles.

Morph descriptions

Anterior constricted morph (pi. V, 3B, 7, 8, 9) : Live collected shells to 25 mm. Inflated,

tumidity only slightly less to slightly greater than height. Outline obliquely suboval, anteriorly

constricted. Posterior margin oblique, gently curved, posterior ventral junction indistinct,

rounded. Ventral margin curved, inclined towards the anterior and merging without a distinct

junction into the broadly rounded anterior margin. Anterior area very small, sloping very

steeply towards the umbo. Ligament extending anteriorly but not filling area completely.

— 336

Sculpture of 26-29, usually 27-28 ribs, all narrower than interspaces, noticeably steep sided and

flat topped if not at all worn, LV sculpture delicate.

Fig. 28-29. — 28 : Plots of Total Shell Length against Height and Anterior to Beak Length for 75 shells of Anadara

polii from throughout its range. 29 : Number of Ribs for 75 shells of Anadara polii from throught its range.

West African “subfossil” globose morph (pi. V, 3C, 4B) : Shells to 40mm. Similar in

outline to the above but some large shells are subspherical (probably gerontic). Sculpture of

24-28 ribs, usually 25-26 but this may be accounted for by wear of the posterior dorsal area.

Ribs very noticeably narrower than interspaces. Ligament filling most of the dorsal area in

large specimens.

Oblong morph (pi. V, 1A-B, 3A, 4A, 5, 6) : Shells to 55 mm in length. Inflated but tumidity

distinctly smaller than height. Outline oblong-subrectangular ; posterior and anterior ventral

junctions distinct, especially posterior; ventral margin more or less parallel to dorsal margin.

Sculpture of 26-27 ribs, the posterior a little wider; rib sculpture on LV prominent especially

on small shells.

Fig. 30. — Internal view of right valve and dorsal view of Anadara polii (Mayer). Anteriorly constricted morph from

Cameroon. (Scale bar = 5 mm.)

Distribution : This species is recorded from Portugal (Setubal), throughout the Mediterranean

south to Angola (Moçâmedes).

Material examined : Mediterranean, Algeria : No precise details, 2 spm. + 1 v., MNHN. Italy :

Sicily, Palermo, 1 spm., leg. Monterosato, 1914; S. Andrea, 2 spm., leg. del Prête, 1928-1929, coll.

Staadt; Circeo-Tirreno, leg. Tittoni, 2.IV. 1957, coll. Staadt; Naples, 5 spm., coll. Petit, 1873; Naples,

1 spm., old coll.; all MNHN. France : St. Raphaël, 1 spm., coll. Locard, 1892; off Banyuls-sur-Mer,

130-190m, 9 spm.; both MNHN. Atlantic Morocco : between 37°01'N and 30°06'N, 20-180m, numerous

spm., sh. and v. from 25 dredging stations of R/V “Vanneau”, 1923-1929; between 36°49’N and

33°43'N, 144-332m, numerous sh. and v. from 6 stations of R/V “Cryos”, BALGIM. VI.1984; all

MNHN. Mauritania : SW of Nouakchott, 17°44'N/16°27'W, 100 m, 2 v., dredged "Leon Coursin”, leg.

Marche-Marchad, 3.II.1957, MNHN. Cape Verde Islands: S. Vicente, 1 v.; off Sâo Tiago,

15°16,5'N/23°47,5' W, 50-65m, 1 v.; 15°26,5'N/23°14'W, 100m, 1 spm., all dredged R/V “Calypso”, leg.

Marche-Marchad, 1959; all MNHN. Senegal : Off Cap Vert, 14 v. ; off Cap Vert 200-300 m, 1 v. ; off

Kayar, 110-120m, 12 v., all leg. Marche-Marchad, 1967; 15°38'N/17°00' W, 130m, 1 v., dredged

“Léon Coursin”, leg. Marche-Marchad, 1.11.1957; 14°50,TN/17°29,3'W, 150m, many v., dredged

“Tenace”, leg. Marche-Marchad, 15.III.1967; 14°23,5'N/17°24,5' W, 65-70m, 1 spm. + 8v.; off

Dakar, 50m, 1 spm.; 200m, 1 spm.; 129-150m, 9 v. ; S of Gorée, 110-112m, 13 v., all dredged R/V

“Gérard Tréca”, leg. Marche-Marchad, 1954-1958; Casamance, 12°32'N/28°8'W, 45m, fine sand,

2 v„ dredged R/V “Louis Sauger”, leg. von Cosel, 28.III.1988; 14°15,8'N/17°28'W, 100m, leg. Leung

Tack; Thiaroye, NNE of Dakar, 7-8m, leg. Marche-Marchad, 6.VI.1956; all MNHN. Liberia :

4°34,5'N/8°3T W, 64m, 2 v. ; 5°21,5'N/9°54,5'W, 73-80m, 13 v., both dredged R/V “Calypso”, leg.

Marche-Marchad, 20.V.1956, all MNHN. Côte d’Ivoire : Off Abidjan, 1 spm. + 9 v. ; off Abidjan,

60 m, 1 spm. ; off Abidjan, 70 m, 4 spm., all leg. Le Loeuff (ORSTOM); off Abidjan, 2 v., leg. Marche-

Marchad; 4°50'N/5°57' W, 70m, 7 v. ; 5°01'N/5°17'W, 40m, 1 spm., both dredged R/V “La Rafale”,

Guinean Trawling Survey, IV.1964; all MNHN. Nigeria : 4°00'N/6°1 TE, 2 v., dredged R/V “Calypso”,

leg. Marche-Marchad, 1956, MNHN. Cameroon : 3°54,5'N/8°53'E, 62-64m, mud, 1 spm.;

3°54'N/8°50'E, 65-70m, mud, 1 spm.; 2°5TN/9°4TE, 80m, mud, 1 spm. ; 2°39'N/9°40'E, 60-65m, mud,

2 spm., all leg. Crosnier, 22.VIII.1963 ; all MNHN. Gabon : Cap Lopez, on beach, 1 v., leg. Chevalier.

1984-1988; 0°32,8'S/8°43,TE, 125-145 m, 1 v„ dredged R/V “Calypso”, leg. Marche-Marchad, 1956,

MNHN. Angola : Off Ambrizete, Zaire province, 80m, 4 v. ; off Mussulo, Luanda province, 90-100m,

muddy ground, 12 v. ; Ilha de Luanda, Luanda province, 120 m, many v. ; Ilha de Luanda, 40-60 m, 2 v, ;

Ilha de Luanda, 90m, 1 v. ; Praia Amelia, Moçâmedes province, 40-60m, 1 v., all leg. Gofas, 1981-1984;

all MNHN.

Biotope : This species is restricted to offshore in depths from 50-200 m.

Map 8.

Distribution of Anadara polii.

Remarks

Of the morphs described the most common in tropical West Africa is the “ anteriorly

constricted” type. In West Africa living specimens are as yet all smaller than 25mm which is

half the size of those living in the Mediterranean. Considering the apparently subfossil samples

the size ranges are more similar with a valve from Gabon reaching 40 mm. The most common

type in the Mediterranean is the “ oblong ” morph but we have only 8 specimens and 1 valve

from West Africa. Nowhere are the two extremes mutually exclusive and we cannot suggest

that there is clinal variation. The globose morph represents many of the shells collected by the

R/V “Vanneau” from off Morocco and is only rarely found in the Mediterranean. The large

examples closely resemble the gerontic specimens of the subfossil samples from Senegal and

— 339 -

such specimens are the basis of both Locard’s A. talismani and probably Kobelt’s A.

sphaerica.

The various morphs are shown to overlap in their distribution and there is a merging of

one into the other when all samples are observed collectively. This degree of overlap can be

seen in figures 31-32 which display the ranges of Length/Height and Length/Anterior/Beak

Length ratios for shells from three parts of the range. These plots also show that the range of

variation is greatest in the tropical West African shells. There is therefore no value in giving

the morphs even varietal status and all are considered to be variants of A. polii.

- 1 - 1 - 1 -

Mediterranean Morocco W. Africa

Fig. 31-32. — 31 : Box plots of Shell Length to Height ratios of shells of Anadara polii from three parts of its range,

Mediterranean, Morocco and tropical West Africa. 32 : Box plots of Length to Anterior to Beak Length of shells

of Anadara polii from three parts of its range, Mediterranean, Morocco and tropical West Africa.

We have chosen to use the name A. polii Mayer for this species and not the more often

used A. diluvii Lamarck. We do not consider that from our examination of the types of A.

diluvii this species to be the Miocene/Pliocene counterpart of the Recent form because (i) the

rib number is 33 not 24-28, (ii) the beaks are situated much more closely to the midpoint,

(iii) the ribs are equal in width to the interspaces.

- 340 -

Anadara eborensis n. sp.

(PI. VI, 1A-D ; fig. 33; map 9)

Type material : Holotype (31. 9 mm), MNHN, off Grand Bassam, Côte d'Ivoire, 5°07' N/3°22' W,

20m, dredged R/V “La Rafale”, Guinean Trawling Survey, leg. Cherbonnier, 21.III.1964. Paratypes :

MNHN, off Grand Lahou, Côte d’Ivoire, 5°00'N/5°28.5'W, 27m, 1 spm., dredged R/V “Calypso", leg.

Marche-Marchad, 1956; NMWZ, Guinea, 9°36'N/14°12' W, 21m, 1 spm., dredged R/V “André

Nizery”, leg. von Cosel, 19.V.1988.

Type locality : Côte d’Ivoire, off Grand Bassam.

Description

Shell to 32 mm in length. Heavy. Slightly inequivalve, LV a little larger. Inflated, almost

as tumid as high, strongly umbonate. Inequilateral, beaks almost in the anterior quarter.

Outline subquadrate, only slightly longer than high. Posterior area broad sloping steeply,

set off by strong but rounded posterior angle ; posterior margin obliquely subtruncate, more or

less straight ; posterior ventral junction distinct, sharply rounded. Median area narrow, more

or less flat except in very earliest stages in which it is deeply sulcate, ventral margin gently

curved or more or less straight. Anterior margin broadly rounded. Dorsal margin straight,

anterior junction almost 90°, posterior junction oblique.

Dorsal area broad, slightly cleft or more or less flat, umbonal separation wide. Ligament

initially developing with a single posterior chevron, then adding anteriorly towards the beaks

and eventually in front of the beaks but chevron number remaining low with up to 5 growth

points on the hinge line, chevrons narrow.

Hinge plate moderately thick, teeth in two series, separation slight with posterior set

pushing over the anterior, anterior set up to 24 teeth, posterior set up to 27 teeth. Teeth

laminar, narrow, vertical.

Sculpture of 24-27 (usually 25) radial ribs, these narrow and only half the width of the

interspaces, steeply angled with narrower, rather flat top ; RV weakly nodulose, LV almost

smooth.

Periostracum rust brown with slightly darker, short, thorn like, recurving bristles arising

from the interspaces of the anterior and median areas ; those on the posterior angle all worn.

Shell white.

Adductor muscle scars unequal, the posterior considerably larger. Internal margin deeply

crenulate.

Selected shell measurements : See in Remarks section under Anadara subglobosa.

Distribution : This species has a restricted distribution from Guinea to Côte d’Ivoire and Gabon.

Material examined : The type material; Guinea : 9°40'N/14°05'W, 18m, many v., dredged R/V

“Calypso", leg. Marche-Marchad, 1956; 9° 12'N/13°43,5' W, 24m, 1 spm.; 9°01'N/13°30'W, 12m,

1 spm., both dredged R/V “André Nizery”, leg. von Cosel, 27.IX.1988; all MNHN. Liberia:

— 341

4°34,5'N/8°31'W, 64m, 1 v., dredged R/V “Calypso", leg. Marche-Marchad, 1956, MNHN. Côte

d’Ivoire : 5°03'N/5°25'W, 20-25m, 1 v., dredged R/V “Calypso”, leg. Marche-Marchad, 21.V. 1956;

off Abidjan, 2 spm., dredged R/V “ Reine Pokou”, leg. Le Loeuff (ORSTOM); both MNHN. Nigeria :

4°34,5'N/8°31'E, 64m, 1 v.; 4°03'N/6°12'E, 32m, 1 v., both dredged R/V “Calypso”, leg. Marche-

Marchad, 1956, MNHN. Gabon : Cap Lopez, 3 v., leg. Chevalier, 1984-1988, MNHN.

Map 9. — Distribution of Anadara eborensis.

Biotope : This species has been dredged from mud and mixed muddy substrates offshores from 18 to

64 m.

Derivatio nominis : eborensis , Latin, derived from eboris , “ivory” with the suffix ensis denoting

place referring to the type locality of the Côte d’Ivoire.

Remarks : The heavy subquadrate appearance of this shell is reminiscent of other species

placed in the subgenus Larkinia but those species have a true amphidetic ligament. The only

Caribbean species with any similarity is Anadara brasiliana but it also has a truly amphidetic

ligament, the ribs are as broad as the interspaces and the rib sculpture is more prominent.

Most akin to A. eborensis is perhaps A. (Esmerarca) reinharti Lowe, 1935, both in the general

shape, the form of the ligament and the weak discrepant rib sculpture. The posterior margin of

A. reinharti by comparison is rounded, there is a slight posterior ventral sinuation and the ribs

are as wide or wider than the interspaces.

— 342 —

Fig. 33. — Internal view of right valve and dorsal view of Anadara eborensis n. sp. Côte d’Ivoire. (Scale bar = 5 mm.)

Anadara subglobosa (Dunker, 1891)

(PI. VI, 2A-B ; fig. 34; map 10)

Area ( Anomalocardia) subglobosa Dunker in Kobelt, 1891 : 99, pi. 26, figs 7-8.

Type material : Most probably in ZMB Berlin. In the MNHN we have located a single specimen in

the Bavay collection which is marked as coming from von Maltzan, collected at Gorée, Senegal. This

agrees with the data available with the type as cited by Dunker and also agrees with his figure (1891 :

pi. 26, fi.g. 8).

Type locality : Gorée, Senegal.

Description

Shell to 19 mm in length. Slightly inequivalve in juveniles, more or less equivalve in adults.

Inflated to strongly inflated, usually with tumidity less than height but some adults with

tumidity greater than height, umbonate but not greatly. Inequilateral, beaks in the anterior 1/3

to 1/4.

Outline subrectangular, adults always distinctly longer than high with the anterior half of

the shell a little more expanded than the posterior, juveniles less so. Posterior area relatively

short, sloping rather steeply and demarcated by a distinct, acutely rounded posterior angle but

this is not so marked in the juveniles ; posterior margin oblique, moderately long, more or less

straight ; posterior ventral junction distinct, roundly acute. Median area strongly sulcate in

post larval shell and to a lesser degree in juveniles to about 8 mm, otherwise gently curved ;

ventral margin gently curved, subparallel to dorsal margin. Anterior area small, anterior

margin broadly rounded, anterior ventral junction obsolete. Dorsal margin straight.

Dorsal area rather wide, more so anterior to the beaks, umbonal separation moderate to

wide. Ligament initially opisthodetic but very rapidly developing anteriorly and appearing

— 343 -

secondarily amphidetic except for a small anterior ligament free area ; chevrons very few, 2-3

in number, very narrow.

Flo. 34. — Internal view of right valve and dorsal view of Anadara subglobosa (Dunker). Mauritania. (Scale bar =

5mm.)

Hinge plate moderately thick; teeth in 2 series, the anterior set pushing below the

posterior at their junction; anterior set up to 18 teeth, posterior set up to 24 teeth. Teeth

laminar, all teeth vertical except for a few slightly oblique posterior marginals.

Sculpture of 28-31 radial ribs, these narrower than interspaces in adults with steeply

angled sides and a rather flat topped appearance. Rib sculpture discrepant, stronger on LV of

rather long, sparse nodules, RV more or less smooth except for weak nodules on anterior ribs.

Interspace sculpture distinct of widely spaced concentric, crescentric notches.

Periostracum rarely preserved in a good state ; generally rust brown in colour with sparse

bristles in the interspaces; anterior and median bristles thorn-like recurved dorsally; on

posterior angle longer, narrower.

Shell white.

Adductor scars unequal, the posterior twice the size of anterior, posterior quadrate;

anterior rounded, often a little raised. Inner margin deeply crenulate.

Selected shell measurements : See below in Remarks section.

Distribution : From Mauritania (17°N) south to Côte d’Ivoire.

Material examined : Mauritania : 17“30'N/16°15'W, 41m, 1 spm., dredged R/V “N’Diago”,

leg. Richer de Forges, 1981, MNHN. Senegal : Gorée, 1 spm., coll. Bavay ex coll, von Maltzan;

Gorée, 1 spm., coll. Jousseaume; SE of Gorée, 14°41'N/17°23,2'W, 17m, fine sand and mud, 2 v.,

dredged R/V “Louis Sauger”, leg. von Cosel, 24.III.1988; S of Gorée, 65m, many v.; 110-112m,

1 v. ; 95-98m, many v. ; SW of Cap Manuel, 50m, 1 v., all dredged “Gérard Tréca”, leg. Marche-

Marchad, 11.1954; 14°50'N/17°29'W, 150m, dredged "Tenace”, leg. Marche-Marchad, 15.III.1967;

14°31,9'N/17°13,5'W, 28m, 1 spm., coll. Leung Tack, 1983-1984; Casamance, Abéné, 13°01,8'N/

17°25,5'W, 53 m, hard ground and fine sand, 1 v. ; 12°46,6'N/17°19,2'W, 32 m, carbonate and fine

sand, 1 v., all dredged R/V “Louis Sauger”, leg. von Cosel, 28-29.III.1988; 14°2,5'N/17°09,l'W,

24m, 2 v., dredged "Cdt. Henri Gomis”, leg. Bodard, 7.XII.1966; 13°01'N/17°24'W, 51-55m,

1 spm. -I- 2 v., dredged, R/V “Calypso”, leg. Marche-Marchad, 1956; all MNHN. Ghana :

4°57'N/2°42'W, 40m, muddy ground, 1 spm. + 1 v., dredged R/V “La Rafale” Guinean Trawling

- 344 -

Survey, leg. Cherbonnier, 19.III.1964; MNHN. Côte d’Ivoire : 4°52,5'N/5°57,5'W, 40 m, hard ground

and calcareous algae, 2 v. ; 5°05'N/3°22'W, 30 m, mud, sand and shell gravel, 2 spm. + 4 v. ;

5°07'N/3°22'W, 20m, 1 spm.; all dredged R/V “La Rafale”, Guinean Trawling Survey, leg. Cher¬

bonnier, III and IV.1964; all MNHN.

Biotope : This species has been collected primarily in deep water from 17-200 m.

Remarks

This species is clearly related to Anadara eborensis (this paper) by the similarity in growth

of the ligament and the shape and sculpture of the radial ribs. It differs from that species in

being rectangular rather than quadrate, that is with a larger Length/Height ratio (fig. 35); and

also less tumid (fig. 35).

Although there is a degree of overlap with these characters the rib number is consistently

different between the two species A. subglobosct having more ribs, 28-31 as against 24-27 for A.

eborensis (fig. 36).

Map 10. — Distribution of Anadara subglobosa (circles) and A. camerunensis (triangles).

The distribution of these species overlap, and we have not found intermediate samples in

the material at hand. It is of interest to note that it does seem possible to distinguish non

overlapping morphologies in some groups yet not in others. The degree of plasticity in shell

form within the Anadara group has never been explained but is well illustrated by referring to

345

any of the major works on the Tertiary faunas of Europe or the Caribbean where a multitude

of forms are described. Until we have understanding of this plasticity the species systematics

will remain fraught with difficulty so long as we are limited to traditional conchological

methods. With the Recent fauna recourse to electrophoretic and genetic methodology could be

advantageous.

Length : Height Length : Tumidity

36 Rib Number

Fig. 35-36. — 35 : Box plots of Length to Height and Length to Tumidity ratios for Anadara eborensis (n = 14) and

A. subglobosa (n = 20). 36 : Bar chart of rib number in Anadara eborensis (mode 25) and A. subglobosa (mode 31).

Anadara senegalensis (Gmelin, 1791)

(PI. VI, 3A-D, 4A-B, 5A-B ; pi. VII, 1-4; fig. 39; map 11)

“Le Robet” Adanson, 1757 : pi. 248, fig. 6.

Area senegalensis Gmelin, 1791 : 3312.

Area pertusa Reeve, 1844 : Sp. 28, pi. V.

Type material : Lectotype (here selected), MNHN, from coll. Adanson, a left valve, 20mm in

length. This is not the valve cited by Fischer-Piette (1942) as the figured specimen in Adanson (1757)

but we argue that the original figure is so poor that it does not adequately represent any of the specimens

labelled by Adanson as “ Le Robet ”. Furthermore the two valves cited by Fischer-Piette are not a pair,

346 —

the right valve does not fit into the left valve and the widths of the dorsal areas are different.

Paralectotype as lectotype, 2 valves.

Type locality : Senegal.

Description

Shell to 25 mm in length. Inequivalve, LV larger than RV. Greatly inflated, tumidity

almost equal to or a little greater than height ; strongly umbonate. Inequilateral, beaks in the

anterior third.

Outline rhomboidal-oval, initially a little longer than high, later almost as high as long.

Posterior area very short and very steep; posterior angle distinct but rounded; posterior

margin long, a little oblique, almost vertical, gently curving in juveniles but with a subtle

angulation in adults. Median area curved except in post larval shells which are sulcate ; ventral

margin curved, posterior ventral junction slightly angulate, anterior ventral junction not

marked but curving into anterior margin which is short, weakly curved and almost vertical.

Dorsal margin straight, rather short.

Dorsal area slightly cleft, rather narrow, umbonal separation slight. Ligament initially

opisthodetic, later apparently amphidetic but with a somewhat larger anterior ligament free

area, chevrons widely spaced, numbering up to 4.

Hinge plate thick, teeth in two series, separation slight, anterior set up to 22 teeth,

posterior to 20 teeth. Teeth laminar, some weakly chevron shaped, all more or less vertical.

Sculpture discrepant, of 23-24 radial ribs, LV with anterior 15-16 ribs strongly nodulose

formed by thickened crossbars, RV with anterior 6-10 ribs more weakly nodulose.

Periostracum a thin rust brown coating except for spicate bristles arising from interspaces,

on posterior area of closely spaced, thin, long, black, erect bristles ; on median area of shorter

wider bristles directed posteriorly.

Shell white.

Adductor scars unequal, posterior twice as large as anterior, pedal retractor scars small

indistinct. Inner margin strongly crenulate corresponding to radial sculpture.

Selected shell measurements : See figure 37.

Casamance variety (pi. VII, 3-4) : This larger (to 29 mm) variant differs from the typical

form in being distinctly longer than high and is therefore oblong-rhomboidal in outline. The

sculpture is slightly weaker but the nodules are still large if not so raised. The shell is thinner

and consequently the hinge plate is weaker and the teeth smaller. This is the form represented

by Adanson’s type specimens.

Distribution : This species has been recorded from Guinea south to Angola (Bengo province).

Material examined : Senegal : No precise locality, 4 spm., coll. H. Fischer; Dakar, 2 v., coll.

Chevalier, 1900; N. Casamance, Kafountine, beach to the south, 4 v., Abéné-Kafountine, beach, many

v. ; S. Casamance, Cap Skirring-Diembéring, on beach, many v. ; Cap Skirring, beach to the south, many

v. ; Bôlon opposite Elinkine, 3 m, 8 v. ; off Kafountine, 3-6 m, 1 v. ; Katakalous Bôlon, 2-4 m, 1 v. ; S of

Cap Skirring, 3-5 m, many v., all leg. von Cosel, 5- 17. III. 1 988 ; off Cap Skirring, 12°22,5'N/17°03'W,

347

20m, 2 v.; off Cap Skirring, 12°23'N/16°52,8'W, 13m, 5 v.; 12°46,9'N/17°29,9'W, 45m, many spm., all

dredged R/V “Louis Sauger”, leg. von Cosel, 27-29.III.1988, all MNHN. Guinea-Bissau : Casamance

border, Essoukoudiak Bôlon, 5-6 m, 2 v., leg. von Cosel, 7.III.1988; 11°58,5'N/16°59'W, 14m, 3 spm.;

11°53'N/16°56,5'W, 11m, 2 spm.; 12°05'N/17°02,5'W, 14m, many spm., all dredged R/V “André

Nizery”, leg. von Cosel, 7.X.1988; all MNHN. Guinea : No precise locality, 2 spm., coll. Parfait, 1889;

Cap Varella, 3 v., coll. Mauny, 1964; Conakry, many v., coll. DufossÉ, 1905 ; all MNHN. Côte d’Ivoire :

Off Abidjan, 1 spm., leg. Marche-Marchad ; Sassandra, Batebré beach, many v., coll. Aubert de la

Rue, 1950; off Abidjan, 4°50'N/5°57'W, 70m, 8 v., dredged R/V “La Rafale”, Guinean Trawling

Survey, leg. Cherbonnier, 4.IV.1964; off Bassam, 20m, 1 spm.; Abidjan region, 20-26m, 27 spm. +

1 sh. from 4 stations, all dredged R/V “Reine Pokou”, leg. Le Loeuff (ORSTOM), 1966-1967; all

MNHN. Togo : Lomé, 14 v., MNHN. Gabon : No precise locality, 1 sh., coll. H. Fischer; Cap Lopez,

beach south of lighthouse point, 6 v., leg. Chevalier, 1984-1988, both MNHN. R.P. Congo : Off

Conkouati, 4°00'S/10°59'E, 19m, many v. ; 4 o 10'S/H°15'E, 19m, 1 spm., both trawled “Kounda”, leg.

von Cosel, XII. 1985; Pointe-Noire, Plage Mondaine, many v. ; Plage Raffinerie, 6 v.. Plage ORSTOM,

2 v.; Baie de Pointe Noire, off Plage ORSTOM, 5-7m, many spm., dredged from muddy fine sand; 3-

4m, 5 spm. + many v., dredged from fine sand and gravel; off Plage Mondaine, 5m, 3 v., dredged from

muddy fine sand; off Songolo, 5-6 m, 1 v., dredged from muddy fine sand, off Plage Raffinerie, 1 m, 3 v.,

all leg. von Cosel, X-XII.1985; all MNHN. Angola: Cacuaco, Bengo province, 0-10m, 1 spm. +

5 sh. + 6 v. ; Moçâmedes, Moçâmedes province, 0-2m, 1 v. ; Ponta do Mussulo, Luanda province, on

beach, 1 v„ all leg. Gofas, 1981-1985, all MNHN.

Fig. 37-38. - 37 : Box plots of the ratios of Total Shell Length to Height (L/H), Tumidity (L/T) and Anterior to Beak

Length (L/A-Bk) of Anadara senegalensis typical form from Guinea-Bissau, Côte d’Ivoire and R.P. Congo (n =

59). 38 : Box plots of the ratios of Total Shell Length to Height and Tumidity of three samples of Anadara

senegalensis from the Casamance region of West Africa (n = 20 per sample).

348 —

Biotope : Live collected material of this species has been collected in shallow depths from the

sublittoral to 30 m.

Map 11-12. — 11 : Distribution of Anadara senegalensis. 12 : Coast of Casamance with the localities of Anadara

senegalensis. 1. Abéné; 2. Kafountine; 3. Diembéring; 4. Cap Skirring. Scale = 10 km.

Remarks

This is the most frequently encountered Anadara in the West African material examined,

and for most of its range it is well defined and not variable. There are, however, a number of

samples principally from the Casamance district of Senegal but also some from the R.P.

Congo and the northern provinces of Angola that include a rather different form. This form is

described above as the Casamance variant.

We are fortunate to have a few large samples of beached valves from Casamance

(map 12) and the Length/Height and Length/Tumidity ratios are plotted in figure 38. This

shows that the sample (Abéné) from the northern part, close to the Gambia River, contains

more “ Casamance ” variants than those from further south, south of the Casamance River,

but that the two forms are not mutually exclusive. The fact that the « Casamance » variant is

— 349 —

also to be found around the Congo river indicates that this may not be clinal variation but is

perhaps linked to environmental conditions close to the estuaries of large rivers. Much more

detailed collecting would be needed to assess whether or not the “ Casamance ” variant is truly

linked to these ecological conditions.

One factor ANOVA table for Length to Height ratios of three samples of Anadara senegalensis

from the Casamance region.

One factor ANOVA, 2 degrees of freedom, F = 15.934, p = .001.

Group

Count

Mean

Std. Dev

Dimbéring

1.149

.067

Cap Skirring

1.17

.086

Abéné

1.273

.095

Comparison

Mean Diff.

Scheffe F-test

Diembéring vs Cap Skirring

.021

.51

Diembéring vs Abéné

.125

14.56*

Cap Skirring vs Abéné

.103

9.979*

* Significant at 95 %.

Fig. 39. — Internal view of right valve and dorsal view of Anadara senegalensis (Gmelin). Typical adult shell from

Côte d’Ivoire. (Scale bar = 5 mm.)

The ANOVA table for the Length to Height ratios shows a statistically significant

difference between the Abéné sample (from the North) and those from Cap Skirring and

Diembéring (from the South). However over the total range the Casamance variant and the

typical form grade into each other. The use of such analyses for the separation of taxa can be

misleading and in general for Anadara species other non continuous variables such as rib

number should always be considered.

Anadara senegalensis would from its general form be considered to belong the. subgenus

Cunearca but it differs in the form of the ligament which has many chevrons and is secondarily

350 —

amphidetic. The ligament of the type species of Cunearca (Area incongrua Say, 1822) consists

of an amphidetic sheet of fibrous ligament with a single outer lamellar chevron. This form of

ligament is also found in Anadara chemnitzi Philippi, which is the closest Caribbean

counterpart to A. senegalensis, and in Anadara pilula, a similar Indo-Pacific species. The

significance of such differences in ligament structure have never been considered within the

Anadariinae, and it is not known whether it should be given any phylogenetic credence.

Anadara camerunensis n. sp.

(PI. V, 6A-C ; fig. 43; map 10)

Type material : Holotype (15.1 mm), MNHN, Cameroon, Victoria (now Limbe)-Bota, 8-10m, leg.

von Cosel, 4.XII.1985. Paratypes : as holotype, 3 spm. ; NMWZ, Cameroon, Victoria-Bota, 5-6 m, leg.

von Cosel, 4.XII.1985, 2 spm.

Type locality : Cameroon, Victoria (now Limbe).

Description

Shell to 16.4 mm in height. Inequivalve, LV larger than RV. Greatly inflated, tumidity

almost as great as length; strongly umbonate. Inequilateral, beaks in the anterior third.

Outline obliquely-oval, subrhomboidal, higher than long. Posterior area short, very

steeply sloping; posterior angle prominent but rounded; posterior margin very long, slightly

oblique, very gently curved. Median area rounded except in post larval shells which are

sulcate; ventral margin curving into anterior margin which is broadly rounded, posterior

ventral junction roundly angulate. Dorsal margin straight.

Dorsal area slightly cleft, wider in front of beaks, umbonal separation moderate.

Ligament initially opisthodetic, later apparently amphidetic but ligament free area a little large

anteriorly, chevrons few, widely spaced, numbering up to 3.

Hinge plate thick, teeth in two series, separation indistinct, anterior set up to 17 teeth,

posterior set up to 17 teeth. Teeth laminar or slightly chevron shaped, more or less vertical.

Sculpture of 21-22 radial ribs, discrepantly nodulose; RV with the anterior 9-11 ribs

nodulose, LV with anterior 13-14 ribs strongly nodulose, all nodules as raised cross bars across

whole of rib.

Periostracum a thin coating, dark rust brown in colour except for interspaces which bear

erect bristles, on the posterior area these are very long rigid black hairs, elsewhere much

shorter and wider.

Shell white.

Adductor scars unequal, posterior twice the size of the anterior, pedal retractor scars

indistinct. Inner margin deeply crenulate corresponding to radial ribs.

— 351 —

Selected shell measurements

Length

(mm)

Height

(mm)

Tumidity

(mm)

Anterior to

beak

(mm)

Hinge line

to ventral

(mm)

Rib No.

Locality

15.1

16.4

14.9

5.4

12.3

[9/13] 21

Cameroon, 8-10 m

12.6

13.2

12.6

4.2

9.8

[11/14] 22

12.4

13.2

11.7

4.0

10.3

[10/14] 22

11.6

12.0

10.1

3.8

9.1

[10/14] 22

11.1

12.7

11.3

3.9

9.7

Cameroon, 24 m

12.4

13.2

12.2

3.7

10.6

Cameroon, 5-6 m

(The numbers in square brackets mark the nodulose ribs in RV and LV.)

Abéné Diembering Abidjan Cameroun Congo

Fig. 40-41. — 40 : Box plots of Length to Height ratios for samples of Anadara senegalensis [Abéné (n = 20),

Diembéring (n = 20), Abidjan (n = 20) and Congo (n = 23)] and A. camerimensis [Cameroon (n = 6)]. 41 :

Graph of Length to Height ratios plotted against Shell Length for Anadara senegalensis (n = 130) and A.

camerunensis (n = 6). Overlapping points are shown as increasing symbol sizes.

352 -

Distribution : This species is restricted to the coast of Cameroon.

Material examined : Cameroon : Victoria/Limbe-Bota, 8-10 m, 5 v., leg. von Cosel; off Victoria,

3°44'N/9°1TE, 24 m, 1 spm; between Wouri estuary and Cap Nachtigal, 3°44' N/9°22' E, 13 m, 1 v., both

trawled “Campo Star”, leg. von Cosel, XII. 1985; all MNHN.

Biotope : This species is infaunal and inhabits muddy fine sand from 5 to 24m.

Derivatio nominis : camerunensis after the Republic of Cameroon, the type locality.

Remarks

We have considered at length that this species might be an ecomorph of Anadara

senegalensis, however we can find no environmental parameters that would give rise to the

changes observed. In A. camerunensis the adult size is only 16mm as compared to 35mm for

A. senegalensis. For most of its ontogeny A. camerunensis is higher than long which is the case

for only the occasional specimens of A. senegalensis (fig. 40-41).

The rib number, although not greatly different, is totally consistent : that of A.

camerunensis from 21-22 and for A. senegalensis 23-24 (fig. 42).

Fig. 42. — Rib Number frequency data for Anadara senegalensis (n = 130) and A. camerunensis (n = 6) shown as

percentile line plots.

Comparing the adults of each, A. camerunensis is more oblique, the posterior ventral

margin being more attenuated. Overlaps with A. senegalensis have not yet been found, and we

have consequently given this form specific status.

Anadara camerunensis has its closests counterpart in the Panamic province, A. mix

(Sowerby, 1833), but differs in the form of the ligament. In A. nux there is a single outer

chevron (fig. 43C) bounding a large median sheet, and the growth is amphidetic. This type of

ligament is found in none of the West African Anadarinae included in this paper but is not

uncommon in the Panamic, Caribbean and Indo-Pacific. The shape of the shell of A. nux and

A. camerunensis would place them in Cunearca. However, should the adaptive form of the shell

— 353 -

be given greater phyletic weight than the form of the ligament? This problem requires a

complete cladistic analysis of the Anadarinae and highlights the inconsistency in the current

generic systematics.

Fig. 43. — A-B, Internal view of right valve and dorsal view of Anadara camerunensis n. sp. Cameroon ; C, Dorsal

view of Anadara mix (Sowerby). Ecuador. (Scale bar = 3 mm.)

Anadara corbuloides (Monterosato, 1878)

(PI. VII, 5A-D; fig. 46; map 12)

Area corbuloides Monterosato, 1878 : 67.

Type material : Not located.

Type locality : Algeria.

Description

Shell to 70 mm in length. Inequivalve, LV larger than RV, most noticeable in small

specimens, obsolete in the larger examples. Inflated, tumidity normally a little greater than half

the length but in gerontic specimens much greater. Inequilateral, beaks in the anterior half.

Outline subelliptical, longer than high. Posterior area poorly defined; posterior angle

rapidly becoming obsolete ; posterior margin evenly rounded except for a small indentation at

the posterior dorsal junction. Median area rounded but sulcate in post larval shell; ventral

margin curved lacking angles with anterior and posterior margins. Anterior margin broadly

rounded to obliquely curved, some becoming rather straight resulting in a subacute anterior

dorsal junction. Dorsal margin relatively long, straight.

Dorsal area becoming wide, slightly cleft, umbonal separation moderate. Ligament

initially opisthodetic becoming secondarily amphidetic; chevrons few, widely separated,

numbering up to 5.

Hinge plate rather narrow, teeth in two series, separation indistinct, anterior set up to

— 354 —

37 teeth, posterior to 39 teeth. Teeth small, pointed, larger teeth slightly chevron shaped, most

vertical, a few lateral teeth a little oblique.

Sculpture of 30-35 radial ribs ; rib sculpture discrepant, RV with a few anterior ribs with

very weak nodules or ridges, LV with all but posterior area ribs distinctly but not strongly

nodulose.

Periostracum a thin coating, rust to olivaceous brown in colour except for interspaces

which bear umbonally directed rigid spicate bristles.

Shell white.

Adductors scars subequal. The posterior a little larger. Inner margin deeply crenulate.

Selected shell measurements : See figure 44.

Fig. 44-45. — 44 : Box plots of the ratios of Total Shell Length to Heigth (L/H), Tumidity (L/T) and Anterior to Beak

Length (L/A-Bk) of Anadara corbuloides (n = 12). 45 : Bar chart of Rib Number for 12 shells of Anadara

corbuloides.

Distribution : This species ranges throughout the Mediterranean and from Spain (Cadiz, Hidalgo,

1916) along the West African coast and south to northern Angola (Luanda), but is nowhere common.

Material examined : Algeria : No precise locality, 1 spm., leg. Joly, 1921, MNHN. Tunisia : Gulf of

Gabes, N. of Djerba, beach, 1 v., leg. Bouchet and Warén, 1982, MNHN. Italy : Viaregio, 2 spm., coll.

del Prête, MNHN. Mauritania : 17°42'N/16°16' W, 54 m, 1 spm., dredged R/V “N’Diago”, leg. Richer

— 355 —

de Forges, 1981, MNHN. Senegal : Kayar, north of Dakar, 110-120m, 1 v., leg. Marche-Marchad,

6.IV. 1967; 14°30,6'N/17°18,9'W, 43m, 1 v., leg. Leung Tack, 1983-1984, both MNHN. Liberia:

4°34,5'N/8°31'W, 64m, 1 v., dredged R/V “Calypso”, leg. Marche-Marchad, 1956, MNHN. Côte

d’Ivoire : Off Abidjan, 1 v., leg. Marche-Marchad, MNHN. Ghana : 4°40'N/2°08'W, 50 m, 1 spm.,

dredged R/V “Calypso”, leg. Marche-Marchad, 1956, MNHN. Cameroon : Between Wouri estuary

and Cap Nachtigal, 3°43'N/9°13'E, 32-35m, 1 v., trawled “Campo Star”, leg. von Cosel, 22-29.XI. 1985,

2°23'N/9°41'E, 45m, 1 v., dredged R/V “Calypso”, leg. Marche-Marchad, 1956, both MNHN.

Angola : Off Ponta das Lagostas, Bengo, province, 30-50 m, 2 spm., leg. Gofas, MNHN.

Biotope : Anadara corbuloides lives in fine muddy sand or mud, well offshore from 30 m to 60 m and

occasionally deeper.

Remarks : Anadara corbuloides apparently has two counterparts in the Panamic Pacific

province, namely A. mazatlanica (Hertlein and Strong, 1943) and Scapharca ( Caloosarca )

biangulata (Sowerby, 1833). The fact that these species are placed in different genera by Keen

(1971) shows how the use of the equivalve condition gives rise to anomalous supraspecific

classification. In A. corbuloides the juveniles are distinctly inequivalve but this condition

becomes obsolete with ontogeny.

356 —

Fig. 46. — Internal view of right valve and dorsal view of Anadara corbuloides (Monterosato). Angola. (Scale bar =

10 mm.)

Genus SENILIA Gray, 1842

Type species : Area senilis Linné, 1758 (SD Gray, 1847).

Senilia senilis (Linné, 1758)

(PI. VIII, 1A-B, 2, 3; fig. 49; map 13)

Area senilis Linné, 1758 : 694.

Type material : One specimen in the Linnean collection, London (Dodge, 1952 : 151).

Type locality : “Jamaica” (10th edition) but later emended to “O. Africano” (12th edition).

Description

Shell to 135 mm in length. Equivalve at all sizes. Inflated about the umbos but wedge

shaped in cross section ; moderately to strongly umbonate. Inequilateral, beaks in the anterior

third, strongly prosogyre.

Outline subrhomboidal-trigonal, anteriorly expanded, posteriorly to some degree attenua¬

te. Posterior area not defined ; posterior angle weak ; posterior margin oblique, slope variable

from 30° to 65°. Median area rather flat, never sulcate even in post larval sizes ; ventral margin

more or less straight, posterior ventral junction subacute to attenuate. Anterior margin

broadly rounded. Dorsal margin relatively short, straight.

Dorsal area short, more or less flat to cleft, rhomboidal with anterior area much more

broad. Ligament initially opisthodetic, developing beyond the beaks 20 mm and secondarily

amphidetic in large or old shells; chevrons strong, numbering up to 8.

— 357 -

Hinge plate becoming massive, teeth in two series, separated by a narrow oblique gap ;

anterior set up to 15 teeth, posterior set up to 16 teeth. Teeth long weakly chevron shaped but

often becoming divided or distorted, mostly more or less vertical.

Sculpture of 13-15 broad flattened smooth ribs, occasionally narrowed and more rounded

especially in the least attenuate shells.

Periostracum persistent, a thin coating with very fine concentric thickenings in the

interspaces. Colour initially olivaceous then reddish brown to black.

Shell white.

Adductor scars subequal. Inner margin with large crenulations.

48 Rib Number

Fig. 47-48. — 47 : Box plots of the ratios of Total Shell Length to Height (L/H), Tumidity (L/T) and Anterior to Beak

Length (L/A-Bk) of Senilia senilis (n 21). 48 : Bar chart of Rib Number for 21 shells of Senilia senilis.

Selected shell measurements : See figure 47.

Distribution : This species ranges from West Sahara (Rio de Oro) south to Angola.

Material examined : Mauritania : Port Étienne (now Nouadhibou) to Nouakchott, many v., from

12 sta., all subfossil. Miss. Gruvel, 1908, MNHN. Senegal : Dakar, Marigot de Hann, 2 sp., 1 v., Miss.

Gruvel, V.1908; Sine-Saloun region, mangroves, 8 spm., leg. Bouchet, 9.VIII.1973; S-Casamance :

Katakalous Bôlon, muddy sand, 3-4 m, many juv. spm.; Ourong Bôlon, on sandbank, low tide, 1 spm..

— 358 —

Map 14. — Distribution of Senilia senilis. The empty circles indicates records of valves with subfossil appearance.

1 v.; Karabane, sandbank, 2 sh., all leg. von Cosel, III.1988; all MNHN. Gambia : 1 sp., coll.

d’Augustin, 1835, MNHN. Sierra Leone : Sierra Leone River, 1 spin., leg. Longhurst, 13.X.1954,

MNHN. Liberia : Cap des Palmes, 2 sh., old coll., MNHN. Côte d’Ivoire : Azuretti Lagoon, Grand

Bassam, 1 v., leg. Aubert de la Rue, 1950, MNHN. Ghana ; Accra, on beach, 3 v.. Miss. Gruvel,

26.1.1910, MNHN. Benin : Icheppê-Olokun, 3 v. ; Lac Abénué, 1 sh., both Miss. Gruvel, 1910, MNHN.

Sâo Tomé : Off Punta Oquedelrey, 5m, 3 sh., 3 v., all juv., dredged R/V “Calypso”, leg. Marche-

Marchad, 1956, MNHN. Cameroon : Victoria/Limbe, on beach, 6 sh., leg. von Cosel. XII.1985,

MNHN. Gabon : Baie de Cap Lopez, 3 sh.. Miss. Gruvel, 1910, MNHN. R.P. Congo : Cocobeach,

1 sh., coll. Soyer, 1969; Loango, 6 sh.. Office Pointe-Noire, 1969; Pointe-Noire, Plage Mondaine, on

beach, 1 v., leg. von Cosel, XII. 1985, ail MNHN. Zaïre : Crique de Moanda, 1 sh., leg. Miss. Gruvel,

1910, MNHN. Angola : Cabinda, 1 sh., leg. C. R. Boettger, 1909; Ponta do Mussulo, Luanda province,

on beach, many sh.; Baia dos Tigres, Moçâmedes province, 1 sh., both leg. Gofas, 1981-1985, all

MNHN.

Biotope : Senilia senilis is a typical marine-estuarine species with lives in sandy mud, fine muddy sand

or fine sand in estuaries, lagoons and creeks with regular tidal and seasonal salinity changes, often in the

vicinity of mangroves, where it may be found in great quantities. It tolerates reduced salinity as well hyper

salinity and lives predominantly in the lower intertidal zone.

Remarks : This species is quite variable in outline with some shells distinctly attenuate

posteriorly and others rather shortened. In the latter this compression results in the ribs being

narrower, more rounded and more elevated (pi. VIII, 3). The functional morphology of this

species was discussed by Yonge (1955) and the recent and fossil ecology by Debenay and Sy

(1989).

— 359 —

Fig. 49. — Internal view of right valve and dorsal view of Senilia senilis (L.). Angola. (Scale bar — 5 mm.)

Genus BATHYARCA Kobelt, 1891

Type species : Area pectunculoides Scacchi, 1834 (OD).

Diagnosis : The genus Bathyarca is placed in the Anadarine by Newell (in Moore, 1969), but, as

shown by Oliver and Allen (1980), the genus contains both epibyssate and endobyssate species thus

encompassing the range of morphology exhibited by both the Arcinae eg. Barbatia and the Anadarinae

eg. Scapharca , The unique feature of the genus is the mantle extension which is present to some degree

regardless of shell shape. This is one of the few examples in the Arcidae where a group of species can be

isolated by a synapomorphy and consequently it is a more rigid group than either the Arcinae or

Anadarinae. There may therefore be a case for raising the genus to subfamily level and creating genera to

separate the epibyssate species from the endobyssate species (Oliver, in prep.).

Bathyarca grenophia (Risso, 1826)

(PI. VII, 4; fig. 50)

Area grenophia Risso, 1826 : 313.

Area pectunculoides Scacchi, 1834 : 82.

Type material : Holotype (1 valve) of A. grenophia in MNHN Paris; type material of A.

pectunculoides not located.

Type locality : Not cited; here selected Nice, Mediterranean France.

Description

Shell to 6 mm in length. Inequivalve, RV fitting into LV, not greatly inflated.

Inequilateral, beaks in the anterior half.

Outline suboval, posteriorly expanded. Posterior area indistinct, posterior angle rapidly

becoming obsolete, posterior margin broadly rounded. Median area flattening or weakly

- 360

sinuate, ventral margin rounded, usually with an indentation at the byssal exit. Anterior

margin rounded but distinctly narrower than posterior. Dorsal margin straight.

Dorsal area narrow, umbonal separation weak. Ligament of few chevrons restricted to

behind the beaks.

Hinge plate weak, teeth in two series separated by a distinctly edentulous space, anterior

set up to 5 teeth, posterior set up to 8 teeth. Teeth small, straight, lateral teeth becoming

strongly oblique.

Sculpture weak, subcancellate. Periostracum weakly haired. Shell white.

Distribution : Throughout the Atlantic and in the subarctic from Norway to Angola in the east and

from Greenland to Bermuda in the west.

Material examined : Ibero-Maroccan Gulf : 36°46' N/07°07' W, 368-371 m, 5 spm. + 2 v. ;

36°36'N/07°24'W, 478-491 m, 1 spm. ; 36°15'N/08°01'W, 1340-1263 m, 15 spm. ; 35°54'N/06”13'W, 133-

137 m, 1 v.; 35°54' N/06T4'W, 150m, 3 spm.; 36°41'N/07T9'W, 543-544 m, 4 spm.; 35°54'N/06°14'W,

293m, 6 spm.; 35°35'N/03°45'W, 480m, 5 spm. ; 35°31'N/07°26'W, 1209-1302m, 2 spm. ;

35°26'N/04°19'W, 170 m, 1 spm. ; 34°24'N/07°31'W, 1203 m, lspm.; 34°21'N/07°24'W, 885-895 m,

6 spm.; 33°49'N/08°24'W, 255-267 m, 5 spm.; 33°46'N/08°30'W, 309 m, many spm.; 33°45'N/08°32'W,

345 m, 1 spm., 6.VI.2984, all dredged R/V "Cryos”, BALGIM campaign, all MNHN. Senegal : 230° off

Cap Manuel, 120-215m, many v. + 1 sh., in stomach of holothurian ; off Dakar, 14°27'N/17°33'W, 150-

250m, many v. ; 14°53'N/17°30' W, 205-230m, 1 spm. -I- 3 v. ; 170-200m, 3 spm. + 19 v. ; Baie de

Gorée, 80-250m, 14 v.; SW of Gorée, 150-250m, 5 v., all dredged “Gérard Tréca”, leg. Marche-

Marchad, 1954-1958; all MNHN. Also based on the material used by Oliver and Allen (1980).

Biotope : This species lives attached to hard substrates and secondary hard substrates in soft

sediment areas such as small stones, dead shells, worm tubes etc. In the north of its range it is found in the

sublittoral zone as shallow as 2 m but further south it submerges to become a bathyal species and off the

west African coast is found from 100-1300 m.

Remarks : Comparing the west African material and more typically that from the greater

end of the depth range with the northern shallow water material it is noted that the former

possesses a thinner almost translucent shell in which the sculpture is very weakly developed. In

these respect it resembles the form pellucida described by Oliver and Allen (1980) from

similar depths off the eastern American coast. Also amongst the BALGIM material from the

Ibero-Maroccan gulf are many specimens of Bathyarca obliqua Philippi. This species is larger

and more elongate than B. grenophia with a resultantly longer hinge line. It also ranges further

north to boreal waters but as yet it has not been recorded from the west African coasts south

of Morocco.

Bathyarca inaequisculpta (Smith, 1885)

(PI. VIII, 5; fig. 51)

Area ( Scapharca) inaequisculpta Smith, 1885 : 267, pi. 17, figs. 8a-d.

Bathyarca dakarensis Locard, 1898 : 321, pi. 8, figs. 25-28.

Type material : Syntypes in BMNH. The syntypes of B. dakarensis are in MNHN.

Type locality : Off Culebra Islands, West Indies. The type locality of B. dakarensis is off Dakar,

Senegal.

- 361 -

Fig. 50-51. — 50 : Internal view of left valve of Bathyarca grenophia (Risso). Senegal, 150-250 m. 51 : Internal view of

right valve and dorsal view of Bathyarca inaequisculpta (Smith). Angola, 3797 m. (Scales bars = 1 mm.)

Description

Shell to 8 mm in length. Inequivalve. Inflated. Inequilateral, beaks in the anterior half.

Outline subcircular, as high or higher than long. Posterior area and posterior angle not

demarcated. Margins other than dorsal not differentiated, round. Dorsal margin relatively

long and straight. Median area curved, not sulcate.

Dorsal area narrow, umbonal separation slight. Ligament with few chevrons restricted to

behind the beaks.

Hinge plate narrow, teeth in two series but separation obscure, anterior set up to 8 teeth,

posterior set up to 10 teeth. Teeth small, straight, lateral teeth becoming strongly oblique.

Sculpture weak, finely decussate, often a little stronger RV. Periostracum weak, sparsely

pilose. Shell white.

Distribution : This species is widely distributed in bathyal and abyssal zones throughout the

Atlantic Ocean from 50 N to I4°S.

- 362 -

Material examined : The material examined is that used by Oliver and Allen (1980).

Biotope : This is a truly deep sea species and is confined to abyssal oozes in which it lives at or near

the surface anchored to sediment particles by a multi threaded byssus. Although it has been found as

shallow as 700 m it is more typically abyssal ranging from 1900-5000 m.

Acknowledgements

We would like to thank Chris Meechan for the line illustrations, Kevin Thomas for the

photography and the National Museum of Wales for these and other facilities required to prepare this

paper. For loan of the major part of the material the first author is grateful to Philippe Bouchet

(MNHN).

Sincere thanks go to our colleague Serge Gofas (MNHN Paris) who contributed ecological data

and collected a considerable part of the material referred to in this paper during his time in Angola.

Most material from Mauritania was donated to MNHN by Bertrand Richer de Forges (ORSTOM),

which is also gratefully acknowledged.

Logistic assistance during the fieldwork of the second author was rendered by several persons and

organisms : the centres of ORSTOM (Institut Français de Recherche Scientifique pour le Développe¬

ment en Coopération) in Dakar (B. Dalmayrac), Conakry (F. Domain), Yaoundé (Ph. Mathieu),

Brazzaville (J. L. Frézil) and Pointe-Noire (M. Barro), the Centre de Recherche Océanographique

Dakar-Thiaroye, Senegal (CRODT) (A. Fontana), the Station de Recherches Halieutiques Limbe,

Cameroon (J. C. Njock) and the Douala Research station of the Ministry of Higher Education and

Scientific Research of Cameroon (the Director). Assistance in the field during littoral work was

received from S. Gilles (ORSTOM Casamance, Ziguinchor), M. Yansane (Fisheries Research

Institute Conakry) and P. Bernard (Libreville). The captains and crews of the vessels “ Louis Sauger”

(CRODT Dakar), “André Nizery ” (ORSTOM), “Campo Star” (PECAM, Douala) and “ Kounda”

(SOCIMPEX, Pointe-Noire) are thanked for their kind collaboration during work on board.

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africains, 2, Paris, Paul Lechevalier. 269 p., 464 figs.

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Oliver, P. G., and J. A. Allen, 1980. — The functional and adaptive morphology of the deep sea species

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Parma. Vol. 2 : 75-256, pis. 19-39.

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particulièrement de celles des environs de Nice et des Alpes-Maritimes. Paris, G. Levrault. Vol. 4

[Mollusques], 440 p., 12 pis.

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(2‘ sér.) : 215-340, pis. 17-19.

Rost, H., 1955. — A report on the family Arcidae (Pelecypoda). Allan Hancock Pacif. Exped., 20 (2) :

177-249.

Scacchi, A., 1834. - Notizie intorno aile conchiglie ed a’zoofiti fossili che si trovano nelle vicinanze di

Gravina in Puglia. Ann. Civ. Reg. Due Siciliae, 6 : 75-84.

Smith, E. A., 1885. — Report on the Lamellibranchiata. Rep. scient, res. H.M.S. « Challenger », 1873-

1876, 13: 1-341.

— 1890. — Report on the marine Moiluscan fauna of the island of St. Helena. Proc. zool. Soc. Lond.,

1890 : 247-317, pis. 21-24.

Stanley, S. M., 1972. — Functional morphology and evolution of byssally attached bivalve mollusks. J.

Palaeont., 46 : 165-212.

Thomas, R. D. K., 1976. — Constraints of ligament growth, form and function on the evolution in the

Arcoida (Mollusca : Bivalvia). Paleobiology, 2 : 64-83.

Verrill, A. E., 1885. — Third catalogue of Mollusca recently added to the fauna of the New England

coast and the adjacent parts of the Atlantic, consisting mostly of deep-sea species, with notes on

others previously recorded. Trans. Connecticut Acad., 6 (2) : 395-350, pis. 42-44.

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and Porcupine Expeditions 1868-1870, part II”). Jahrb. Dt. Malakozool. Ges., 7 : 197-200.

Yonge, C. M., 1955. - A note on Area ( Senilia) senilis Lamarck. Proc. malac. Soc. Lond., 31 (5-6) : 202-

208.

Plate I

1A-D. -- Area noae Linné : West Sahara, off Cap Barbas, 21°05'N/17°14'W, 43-45m, MNHN. 73mm. 1A,

periostracum removed.

2. — Area noae Linné : Cape Verde Islands, Ilha do Sal, Santa Maria, on beach, MNHN. 11.5 mm.

3A-D. — Area bouvieri Fischer : Angola, Cacuaco, Bengo province, 5-10 m, MNHN. 60 mm. 3A, periostracum

removed.

4. — Area bouvieri Fischer : Angola, Corimba, Luanda province, I0-20m, MNHN. 11mm.

— 366

Plate II

1A-D. — Area avellana turbatrix n. ssp. : Holotype. Angola, Santo Antonio, Benguela province, intertidal, rocks.

MNHN. 31mm. 1A, periostracum removed.

2. — Area avellana turbatrix n. ssp. : Paratype. Angola, Lucira, Moçâmedes province, MNHN. 18.7mm.

3A-B. — Area imbricata Bruguière : Florida, NMWZ. 50mm. 3A, periostracum removed.

4. — Area avellana Lamarck : Seychelles, MNHN. 30mm, periostracum removed.

5A-B. — Area tetragona Poli : Ireland, Berehaven, Bantry Bay, NMWZ. 21.3 mm.

6. — Area tetragona Poli : England, Falmouth, NMWZ. 26.6 mm.

7A-B. — Acar plicata (Dillwyn) : Cape Verde Islands, Mindelo, Sâo Vicente, MNHN. 7A, 19.1mm; 7B, 18.2mm.

8A-B. — Acar pulchella (Reeve) : Mediterranean, Algeria, MNHN. 18.2 mm.

Plate III

1A-B. — Barbatia complanata (Bruguière) : Côte d’Ivoire, Canal de Vridi, Abidjan, MNHN. 1A, 51 mm; IB, 18mm.

2. — Barbatia complanata (Bruguière) : Angola, Chapeu Armado, Moçâmedes province, rocks at low tide, MNHN.

40 mm.

3. — Barbatia complanata (Bruguière) : Angola, Caotinha, Benguela province, MNHN. 33 mm.

4. — Barbatia complanata (Bruguière) : Angola, Lucira (Praia do Cesar), Moçâmedes province, MNHN. 45 mm.

5A-B. — Barbatia complanata (Bruguière) : Angola, Praia Amelia, Moçâmedes province, rocks at low tide, MNHN.

5A, 22 mm; 5B, 16 mm.

6A-B. — Barbatia gabonensis n. sp. : Holotype. Gabon : off Mayumba, 3°25'S/9°56'E, 100m, MNHN. 27.7mm.

7A-B. — Barbatia ionthados n. sp. : Holotype. Côte d’Ivoire, Sud Bassam, 200 m, MNHN, 20.6 mm.

8. — Barbatia legumen (Lamy) : Angola, Corimba, Luanda province, Praia Etambar, between rocks at low tide,

MNHN. 41mm.

9A-B. — Barbatia legumen (Lamy) : Angola, 10 km. S of Ambrizete, Zaire province, intertidal, on beach, MNHN.

24 mm.

10. — Barbatia legumen (Lamy) : R.P. Congo, Pointe-Noire, Plage Mondaine, MNHN. 53 mm.

— 370 —

Plate IV

1A-B. — Barbatia (Nipponarca) allocostata n. sp. : Holotype, Guinea-Bissau : Mouth of Rio Geba, 11°57,5'N/

16°27'W, 7 m, MNHN. 27.7 mm.

2. — Barbatia ( Nipponarca ) allocostata n. sp. : Paratype as holotype, MNHN, 28 mm, periostracum removed.

3A-B. — Anadara geissei (Dunker) : Angola, Baie de Corimba, Luanda province, 10-20m, MNHN. 71mm.

4A-B. — Anadara geissei (Dunker) : Angola, Cacuaco, Bengo province, 5-10m, MNHN. 4A, 33mm; 4B, 18mm.

5. — Anacara geissei (Dunker) : Guinea, 9°50'N/14°14'W, 15m, MNHN. 52mm.

6A-B. — Anadara geissei (Dunker) : Cape Verde Islands, Sâo Vicente, Baia Porto Grande, on beach, MNHN. 6A,

50 mm; 6B. 48 mm.

Plate V

1A-B. — Anadara polii (Mayer) : Mediterranean, Banyuls, MNHN. 34 mm, oblong morph.

2. — Anadara polii (Mayer) : Mediterranean, Naples, MNHN. 39 mm, intermediate form.

3A-C. — Anadara polii (Mayer) : Atlantic Morocco, MNHN. 3A, 30°24'N/09°54'W, 105 m, 28 mm, oblong morph.

3B, 30°26'N/09°44'W, 65m, 23mm, anteriorly constricted morph. 3C, 30°05'N/09°50'W, 110m, 22mm, globose

morph.

4A-B. — Anadara polii (Mayer) : Senegal, 14°50,1'N/17°29,3' W, 150m, MNHN. 4A, 31mm, oblong morph. 4B,

29 mm, globose morph.

5. — Anadara polii (Mayer) : Côte d’Ivoire, 05°01'N/05 °17'W, 40m, MNHN. 24mm, oblong morph.

6. — Anadara polii (Mayer) : Côte d’Ivoire, off Abidjan, 70m, MNHN. 22mm, oblong morph.

7. — Anadara polii (Mayer) : Senegal, off Dakar, 200m, MNHN. 24mm, anteriorly constricted morph.

8. — Anadara polii (Mayer) : Cameroon, 02°39'N/09°40'E, 60-65 m, MNHN. 26mm, anteriorly constricted morph.

9. — Anadari polii (Mayer) : Gabon, 00°32,8'N/08°43,l'E, 125-145m, MNHN. 39mm, anteriorly constricted morph.

— 374 —

Plate VI

IA-D. — Anadara eborensis n. sp. : Holotype. Côte d’Ivoire, off Grand Bassam, 20m, MNHN. 31.9mm.

2A-B. — Anadara subglobosa (Dunker) : Mauritania, 17°30'N/16°15'W, 100m, MNHN. 18.5mm.

3A-D. — Anadara senegalensis (Gmelin) : Côte d’Ivoire, off Abidjan, 20 m, MNHN. 3A-C, 21.8 mm. 3D, 23.5 mm.

4A-B. — Anadara senegalensis (Gmelin) : Guinea-Bissau, 12°05'N/17°02,5'W, 14m, MNHN. 21.8mm.

5A-B. — Anadara senegalensis (Gmelin) : Angola, Cacuaco, Bengo province, 0-10m, MNHN. 15.8mm.

6A-C. — Anadara camerunensis n. sp. : Holotype. Cameroon, Victoria/Limbe, 8-10m, MNHN. 15.1mm.

— 376 —

Plate VII

1. — Anadara senegalensis (Gmelin) : Senegal, South Casamance, Cap Skirring-Diembéring, on beach, MNHN.

23.1 mm.

2. — Anadara senegalensis (Gmelin) : Senegal, South Casamance, Cap Skirring-Diembéring, on beach, MNHN.

25.4mm, Casamance variant.

3. — Anadara senegalensis (Gmelin) : Senegal, North Casamance, Abéné-Kafoutine, on beach, MNHN. 23.0mm,

intermediate form.

4. — Anadara senegalensis (Gmelin) : Senegal, North Casamance, Abéné-Kafoutine, on beach, MNHN. 26.2 mm,

Casamance variant.

5A-D. — Anadara corbuloides (Monts.) : Angola, off Ponta das Lagostas, Bengo province. 30-50m, MNHN. 69mm.

— 378 —

Plate VIII

1A-B. — Senilia senilis (Linné) : Angola, Cacuaco, Bengo province, MNHN. 92 mm.

2. — Senilia senilis (Linné) : Angola, Pta. do Mussulo, Luanda province, MNHN. 50 mm.

3. — Senilia senilis (Linné) : Gabon, Cap Esterias, Pointe Idolo, MNHN. 39mm.

4. — Bathyarca grenophia (Risso) : Morocco, 35°35'N/03°45'W, 480 m, MNHN. 8.4 mm.

5. — Bathyarca inaequisculpta (Smith) : Angola, 14°40'S/09°54'E, 3797 m, NMWZ. 6.7 mm.

6A-B. — Bentharca asperula (Dali) : Angola, 14°31,8'S/09°46'E, 3975m, NMWZ. 10.7mm.

Plate IX

Scanning electron micrographs

n. ssp. and B, Area imbricala

of the periostracal bristles from the carinal ridge of : A, Area avellana turba-

(Brug.) from Florida. (Scale bar = 0.5 mm.)

Bull. Mus. natl. Hist, nat., Paris, 4 e sér., 14, 1992,

section A, n" 2 : 383-404.

El género Hygromia Risso, 1826 en la Peninsula Ibérica,

con description de Hygromia gofasi sp. nov.,

y consideraciones sobre la interpretadon funcional

del aparato estimulador de Hygromiidae

por Carlos E. Prieto y Ana I. Puente

Resumen. - Una nueva especie de Hygromia, H. gofasi sp. nov., se describe de una localidad de

Andorra. Sus caracteristicas anatômicas, intermedias entre los dos subgéneros descritos, no permiten

su inclusion en ninguno de ellos. Ademâs, se redescribe Helix Tassyi Bourguignat, 1884 a partir del

holotipo, que por el momento se considéra especie valida de Hygromia. Por otra parte, se ha efectuado

una revision bibliogrâfica de las especies del género en la Peninsula Ibérica, lo que, junto al estudio de

numeroso material, ha permitido perfilar sus distribuciones : H. cinctella en la region de Montpellier y en

Pyrénées-Atlantiques, donde ha sido introducida ; H. limbata, ampliamente extendida desde el sur de

Aude y norte de Barcelona hasta el centra de Cantabria, y hasta la Sierre de la Demanda hacia el interior

peninsular ; H. tassyi en una pequena region del sur de Ariège. Finalmente, se discuten las dos posibles

vias de émision de la secreciôn mucosa en Hygromia durante la côpula, concluyendo que ésta se produce

por el extremo de la estructura vaginal interna, previo almacenamiento en el saco accesorio, lo que

invalidaria la hipôtesis que considéra al saco accesorio como un saco del dardo degenerado. Ademâs, se

aportan otros datos que apoyan la hipôtesis de la funcionalidad del saco accesorio de Hygromiidae como

reservorio de la secreciôn mucosa.

Résumé. — Une nouvelle espèce du genre Hygromia, H. gofasi sp. nov., est décrite d’une localité

d’Andorre. Ses caractéristiques anatomiques, intermédiaires entre les deux sous-genres décrits, ne

permettent de l’inclure dans aucun d’entre eux. Helix tassyi Bourguignat, 1884 est redécrite à partir de

l’holotype et considérée comme une espèce valide à'Hygromia. Une révision bibliographique des espèces

du genre dans la Péninsule Ibérique, ainsi que l’étude d’un abondant matériel ont permis de préciser les

distributions : H. cinctella dans la région de Montpellier ainsi que dans les Pyrénées-Atlantiques, où elle a

été introduite ; H. limbata très répandue depuis le sud de l’Aude et le nord de Barcelone jusqu’au centre de

Cantabria et, vers l’intérieur péninsulaire, jusqu’à la Sierra de la Demanda ; H. tassyi dans une petite

région du sud de l’Ariège. Finalement, les deux voies possibles d’émission de la sécrétion muqueuse

pendant la copulation chez Hygromia sont discutées. Il est conclu que celle-ci se produit par l’extrémité de

la structure vaginale interne, avec au préalable une accumulation dans le sac accessoire, ce qui invaliderait

l’hypothèse selon laquelle le sac accessoire serait un sac du dard dégénéré. D’autres données sont

apportées à l’appui de l’hypothèse de la fonctionnalité du sac accessoire des Hygromiidae comme

réservoir de la sécrétion muqueuse.

C. E. Prieto y A. I. Puente, Departamento de Biologia Animal y Genética, Facultad de Ciencias, Universidad del

Pais Vasco, Apdo. 644. 48080-Bilbao (Espafia).

— 384 —

Introducciôn

La clasificaciôn del género Hygromia Risso, 1826 ha sufrido numerosas vicisitudes en los

ültimos anos a causa de las diferentes interpretaciones de las estructuras de valor taxonômico,

especialmente del aparato genital. Un resumen de la misma se présenta en Giusti y

Manganelli (1987), quienes consideran que Hygromia (con los subgéneros Hygromia s. str. y

Riedelia ) es un género independiente de Zenobiella, Lozekia, Ganula y Pyrenaearia, taxones

que anteriormente han estado incluidos en Hygromia.

Asi, Hygromia incluiria ünicamente dos especies, Hygromia (s.str.) cinctella (Draparnaud,

1801) e H. (Riedelia) limbata (Draparnaud, 1805). Sin embargo, Bourguignat (1884), en uno

de sus ultimos trabajos, describiô la nueva especie Helix tassyi de Auzat (Ariège), indicando su

pertenencia « au groupe des Limbata , groupe composé de formes spéciales à la chaîne des

Pyrénées et aux contrées occidentales de la France », y remarcando que « Aucune de ces

Hélices ne peut être confondue avec la Tassyi, qui est, sans contredit la plus caractérisée et la

plus remarquable des formes de ce groupe ». Esas otras formas a que hace referenda

Bourguignat (1884) ( odeca Bourguignat in Locard, 1882, hylonomia Bourguignat in Locard,

1882 y sublimbata Bourguignat in Locard, 1882) son incluidas entre los sinônimos de H.

limbata por Germain (1930), quien, no obstante, considéra a Hygromia tassyi especie valida.

La ünica menciôn reciente en este sentido es la de Richardson (1980), quien también la

incluye entre los taxones vâlidos de Hygromia. Por el contrario, Bofill et al. (1918) incluyen

en la « forma pirenaica de H. limbata » a H. tassyi.

No hace mucho tiempo tuvimos ocasiôn de recolectar en una localidad de Andorra

material perteneciente a Hygromia pero no asignable a H. limbata ni a H. cinctella. Dada la

escasa distancia entre esta localidad y la tipica de H. tassyi, referimos en principio tal material

a esta ultima. Sin embargo, una comparaciôn con el holotipo de H. tassyi no ha confirmado tal

suposiciôn, por lo que el material procedente de Andorra es asignado a un nuevo taxôn,

Hygromia gofasi sp. nov. Ademâs, se redescribe y figura H. tassyi a partir del citado holotipo.

Por otra parte, el estudio de material referible a H. cinctella procedente del departamento

de Pyrénées-Atlantiques, asi como otro numeroso para H. limbata de diversas localidades

peninsulares, ha permitido revisar y actualizar los datos de las especies del género en la

Peninsula Ibérica, asi como discutir las distintas interpretaciones dadas a las partes del aparato

estimulador de Hygromia.

Hygromia gofasi sp. nov.

Locus typicus : Santuario de Meritxell (Andorra, CH8412, 1600m), 24.07.1983, C. E. Prieto y

A. G. Prieto leg., 15 ej., bajo piedras esquistosas junto a la fuente del santuario. Holotipo y 12 paratipos

en la colecciôn de Malacologia de la Universidad del Pais Vasco ; 2 paratipos en el Muséum national

d'Histoire naturelle de Paris.

Descri pciôn

Concha (figs. 2, 4, 6) : Globulosa, convexo-cônica por encima y globosa por debajo ;

ombligo casi recubierto; espira cônica formada por 5.5-6 vueltas convexas de crecimiento

— 385 —

lento; ultima vuelta poco mâs ancha que la anteültima, redondeada y apenas descendente;

suturas marcadas ; abertura oblicua y ovalar con peristoma blanquecino, frâgil, algo reflejado

y con un labio interno blanco bien marcado ; borde columelar ensanchado y reflejado sobre el

ombligo; câscara delgada, translücida, de color côrneo amarillento, sin banda carénai y

frecuentemente con escoriaciones ; estriaciôn fina con microescultura a modo de pequenas

escamas.

Dimensiones del holotipo : diâmetro = 10.8mm; altura = 7.6mm.

Fig. 1-3. — Conchas de las especies de Hygromia conocidas anatômicamente. 1, H. cinctella (Peyrehorade, Pyrénées-

Atlantiques); 2, H. gofasi sp. nov. (Meritxell, Andorra); 3, H. limbata (Kakouetta, Pyrénées-Atlantiques). Todas,

x 2.65.

Aparato genital (figs. 7-12) : Gônada, conducto hermafrodita, glândula de la albûmina y

espermoviducto sin especiales caracteristicas. Parte masculina : Conducto deferente largo y

delgado. Flagelo corto y puntiagudo (1 = 1.5-2 mm). Epifalo muy largo, con grosor uniforme

y generalmente enrollado. Musculo retractor del pene largo y delgado. Pene cilindrico y mitad

de largo que el epifalo ; esta plegado sobre si mismo por causa de una fuerte vaina conjuntivo-

Figs. 7-12. — Hygromia gofasi sp. nov. : aparato genital y algunas de sus partes (Meritxell, Andorra). 7, parte distal

del aparato genital ; 8, papila penial y dos secciones transversales a diferentes niveles ; 9, vista lateral del complejo

del saco del dardo ; 10, interior de la vagina mostrando el cono vaginal (holotipo) ; 11, dardo ; 12, parte distal del

aparato genital de otro paratipo. Escala : 1 mm.

388 —

muscular existente entre la parte proximal del pene y la region atrial. En el interior del tercio

distal del pene se encuentra una papila penial cilindrica (fig. 8), de unos 3 mm de longitud y

con abertura apical ; en secciôn transversal muestra una pared gruesa con dos pequenas

lagunas y un canal central en forma de estrella. Parte femenina : Oviducto fibre de mediana

longitud, generalmente plegado. De su base parte un conducto tan grueso como el oviducto

fibre y de mediana longitud que desemboca en una bursa copulatrix muy larga y delgada, con

su parte basal mâs engrosada que la estilizada parte distal. Glândulas mucosas, 6 a 8 que

parten de cuatro puntos, dispuestas radialmente alrededor de la parte inicial de la vagina.

Vagina corta y muy engrosada, con dos sacos en uno de sus lados, el interno mâs grueso y

corto que el externo, el cual esta diferentemente orientado y algo arqueado sobre el interno

(fig. 9). El interior de la vagina esta ocupado casi totalmente por una estructura alargada,

cônica y adosada a la pared de la vagina en el lado donde estân situados los sacos (fig. 10); el

citado cono vaginal esta perforado en su extremo y generalmente doblado sobre si mismo ; en

el lado vaginal présenta una larga grieta que, cuando estâ abierta, muestra numerosos pliegues

en sus labios y un profundo surco en el centro, recorrido por un pliegue, donde desembocan

los sacos interno (= saco accesorio, carente de dardo) y externo (= saco del dardo),

respectivamente en los extremos superior e inferior de la grieta. Este surco, una vez rebasada la

salida del saco con dardo, se continüa por un conducto hasta el extremo apical del cono,

donde se abre a la vagina. En la parte basal del cono vaginal se aprecia un canal, que se dirige

hacia la base de las glândulas mucosas, y numerosos pequenos pliegues. El saco interno, de

paredes gruesas y musculosas, estâ vacio, mientras que el externo présenta un dardo

ligeramente retorcido y acanalado en toda su longitud (fig. 11 ). Finalmente existe un atrio

corto.

Râdula : Formula 25-26 + C + 25-26. Diente central con una fuerte plaça basal, un

grueso mesocono y dos minûsculos ectoconos. Primeros dientes latérales con un grueso

mesocono y un corto y grueso ectocono. Ultimos latérales con mesocono con una

protuberancia en el lado interno. Dientes marginales con mesocono de 2 6 3 puntas

proyectado sobre el ectocono del diente anterior y ectocono dividido de 2 a 5 cûspides

irregulares.

Derivatio nominis : La nueva especie esta dedicada a Serge Gofas, sin cuya ayuda y valiosas

sugerencias no hubiera sido posible la description del taxon.

Hygromia tassyi (Bourguignat, 1884)

Helix tassyi Bourguignat, 1884, Bull. Soc. Malac. France, 1 : 357.

Locus typicus : « La vallée de Vicdessos, sur les rochers humides des contreforts du pic du

Montcalm, au-dessus du Village d’Auzat (Ariège) ». Holotipo en colecciôn Bourguignat, Muséum

d'Histoire naturelle de Genève.

Redescripciôn

Concha (fig. 5) : Pequena (diâmetro = 9.8 mm; altura = 6.4 mm), globosa, algo

deprimida, convexo-redondeada por encima, casi aplanada en el âpice, con ombligo muy

estrecho y casi totalmente recubierto por el borde columelar; espira formada por 5 1/4 vueltas

poco convexas, de crecimiento lento y suturas poco profundas; ültima vuelta apenas mayor

— 389 —

Figs. 13-18. — Hygromia cinctella : aparato genital y algunas de sus partes (Peyrehorade, Pyrénées-Atlantiques). 13,

parte distal del aparato genital; 14, papila penial y dos secciones transversales a diferentes niveles; 15, vista

posterior del complejo del saco del dardo ; 16, secciôn longitudinal del complejo del saco del dardo ; 17, dardo ; 18,

interior de la vagina mostrando el cono vaginal. Escala : I mm.

- 390 —

que la anteültima, angulosa al principio, con una banda carénai blanquecina estrecha que

desaparece hacia la abertura. Abertura obllcua, ovalada, apenas descendente; peristoma

blanquecino, frâgil y no engrosado, con el borde columelar reflejado sobre el ombligo. Câscara

frâgil, translücida, de color olivaceo claro, con estriaciôn irregular poco marcada.

Posiciôn sistemâtica de Hygromia gofasi sp. nov. E H. tassyi

La concha de H. gofasi (figs. 2, 4) se diferencia de las otras especies de Hygromia (figs. 1,

3, 5) en la falta compléta de la banda y de la angulosidad carénai, présente siempre en H.

cinctella , frecuentemente en H. limbata y visible en el holotipo de H. tassyi. En comûn con H.

limbata, présenta una abertura con peristoma provisto de reborde interno ; la microescultura

de la concha (fig. 6), formada por crestas muy poco marcadas, parece asi mismo mâs similar a

la de H. limbata (Giusti y Manganelli, 1987 : pl. 8, figs. C-D). En lo que se refiere al tamano,

H. gofasi es notablemente mâs pequena que H. limbata (diâmetro : 12-17 mm, segûn Germain,

1930), aunque se aproxima a las dimensiones minimas citadas por Bofill et al. (1918) de

algunas localidades pirenaicas.

Las peculiaridades conquiolôgicas de H. tassyi la separan de las demâs especies del

género; no obstante, su validez sistemâtica queda pendiente hasta que sea posible estudiar

anatômicamente ejemplares topotipicos.

Anatômicamenle, las diferencias senaladas por Giusti y Manganelli (1987) entre los

subgéneros de Hygromia parecen claras : En Hygromia s. str. (figs. 13-18), el saco del dardo es

de tamano similar al accesorio y estâ provisto de un dardo retorcido, la bursa copulatrix es

oval-alargada con un conducto bastante largo, y el pene y epifalo son de longitud media,

mientras que en Riedelia (figs. 19-21), el saco del dardo es mâs esbelto y pequeno que el

accesorio y estâ provisto de un dardo arqueado, la bursa copulatrix es larga y delgada y con

conducto bastante corto, y finalmente el pene y epifalo son muy largos y delgados. Ademâs se

ha observado en H. limbata que el atrio estâ envuelto por una vaina que en uno de los lados

forma una cavidad tapizada por crestas o gruesas papilas (fig. 20), carâcter que no ha sido

observado en las otras dos especies del género investigadas anatômicamente, y que recuerda a

la cavidad o vaina présente en la region atrial de Monachoides (Schileyko, 1972, 1978).

Estas diferencias, sin embargo, no son tan marcadas si se tiene en cuenta el aparato

genital de H. gofasi. Este présenta algunas estructuras que recuerdan a las descritas para H.

cinctella , especialmente la forma y el tamano del saco del dardo, curvado sobre el saco

accesorio, la forma del dardo, ligeramente retorcido, y finalmente, la posiciôn de los sacos

cerca del atrio, mientras que, por el contrario, la estructura de la papila penial, alagarda y con

lagunas, y la gran longitud del epifalo respecto del pene, asi como la morfologia del cono

vaginal y de la bursa copulatrix indican una mayor relaciôn con H. limbata.

No obstante, varias de las caracteristicas que relacionan estas dos ultimas especies parecen

ser plesiomôrficas para Hygromia : una papila penial larga y cilindrica la presentan numerosos

géneros de Hygromiinae, mientras que una abertura larga en el cono vaginal (fig. 22), un

dardo con aristas desarrolladas y una bursa copulatrix alargada con un conducto corto

aparecen también en Zenobiella (Giusti y Manganelli, 1987) ; por el contrario, parecen ser

caracteristicas apomôrficas del género el corto flagelo frente a un epifalo muy largo y la

acanaladura a lo largo del dardo, originada posiblemente a partir de un ensanchamiento de

391 -

Figs. 19-23. — 19-21, Hygromia limbata : 19, aparato genital (Monte Altxueta, Navarra); 20, interior de la vagina

mostrando el cono vaginal y la vaina atrial (Kakouetta, Pyrénées-Atlantiques); 21, dardo (como la fig. 19); 22,

secciones esquemâticas longitudinales de la vagina mostrando la relaciôn entre los sacos y las estructuras

vaginales : izquierda, H. cinctella, centro, H. limbata , derecha, Zenobiella subrufescens (modificado de Giusti y

Manganelli, 1987); 23, partes evertidas del aparato genital de H. cinctella mostrando la posiciôn de los conductos

internos del aparato estimulador (modificado de Giusti y Manganelli, 1987). Escala : 1 mm.

— 392 —

dos aristas de las cuatro existentes en el dardo de Zenobiella. H. gofasi se encontraria en una

posiciôn intermedia entre Hygromia s. str. y Riedelia, por lo que cabe preguntarse hasta qué

punto tiene sentido la diferenciaciôn subgenérica.

Por otra parte, y al margen de lo anterior, la morfologia angulosa de la concha y la falta

de peristoma en H. cinctella recuerdan a ejemplares juveniles de H. limbata, como lo atestiguan

las determinaciones errôneas de H. cinctella que se comentan en el siguiente apartado;

igualmente, el largo conducto de la bursa copulatrix y la reducida longitud de la parte

masculina, en comparaciôn con los de H. limbata, parecen indicar un origen de H. cinctella a

partir de individuos no adultos de una especie ancestral de Hygromia que hubiesen alcanzado

prematuramente la madurez sexual. En este sentido, Gould (1977 : figs. 47-48) présenta la

formaciôn iterativa de morfos carenados originados por pedogénesis en Poecilozonites

bermudensis en la que, al igual que en H. limbata, las conchas juveniles son carenadas mientras

que las adultas sôlamente angulosas.

Revision bibliogrâfica de las especies de Hygromia

en la Peninsula Ibérica

Las citas referida a Hygromia cinctella del sur de Francia y noreste de Espana son

numerosas, pero la mayoria son menciones genéricas y no recogidas aqui; las localidades

concretas son muy escasas, y parte deben ser consideradas errôneas :

Fagot (1880) indica que gran parte de las determinaciones realizadas por Mermet (1843)

son errôneas y, en concreto, senala que la cita de H. cinctella de Parc de Pau (YN19) debe

referirse a conchas juveniles de H. limbata, indicando lo mismo para las de Nansouty (1872),

quien la citô de Flendaye (XP00) y Cambo-les-Bains (XP20); Germain (1930) parece seguir

este criterio, ya que no menciona la presencia de H. cinctella en el departamento de Pyrénées-

Atlantiques. Sin embargo, Watson (1919) refiere material de Ciboure (XP10) a H. cinctella,

presentando figuras de la concha y del aparato genital que confirman su identificaciôn y,

también, en cierto modo, las localidades citadas por Nansouty (1872), situadas a muy escasa

distancia y que, por este motivo, consideramos validas.

Por otra parte, Vilella (1965) cita H. cinctella de Areo (CH61), en el Pirineo de Lérida,

pero no H. limbata, especie profusamente citada de dicha region por Boeill y Haas (1920a);

en este sentido, Haas (1929) refiere a H. limbata la cita de H. cinctella de Graells (1846) para

« Alta Cataluna ». El examen de una concha de las recogidas por Vilella (1965) muestra una

microescultura tipica de H. limbata, por lo que la hemos referido a esta especie. En cuanto a la

cita de H. cinctella (Larraz y Campoy, 1980 ; Larraz et al., 1981) de Quinto Real (Navarra,

XN26), no es mencionada posteriormente por Larraz y Jordana (1984), quienes indirecta-

mente la consideran referida a H. limbata.

Por ültimo, citan H. cinctella André (1982, fig. 1 : Ganges : 3 km W, EJ56; Arboras : les

Frigoules, EJ34; Laroque, EJ56; Le Claux, EJ45; Cambo, EJ67 ; La Cadière, EJ66) y Perjesi

(1985 : Montpellier, EJ73).

En lo que respecta a H. limbata (ver Anexo I), sôlamente hemos encontrado dos citas

errôneas : el material citado como tal por Ojea y Anadon (1983) del Monte Naranco

(Asturias, TP60), una vez examinado, ha resultado ser Mengoana brigantina (Da Silva Mengo,

— 393

1867); por otro lado, Bofill y Haas (19206) comentan que la localidad de Vallvidrera (DF38),

de la colecciôn Salvanâ, debe ser considerada un error de catalogaciôn.

Respecto a Helix tassyi, como ya se ha comentado, fue considerada un sinônimo de H.

limbata por Bofill et al. (1918) pero no por Germain (1930), quien, basândose en la

descripciôn original, la considerô una especie valida. Las localidades citadas por Locard

(1894) y Germain (1930) no son mas que repeticiones mâs o menos complétas de la original

(CH72), pero Fagot (1890) anade otras dos : « Entre la cascade de l’Arse et le port de

Guillou » y « Vallée d’Aulus », ambas en CH63.

Distribuciôn geogrâfica de las especies del género Hygromia

H. gofasi (fig. 24)

Conocida hasta ahora ûnicamente de la localidad tipica, en Andorra.

— H. tassyi (fig. 24)

Conocida hasta ahora de la localidad tipica y de otras dos cercanas situadas al noroeste,

todas por encima de los 1500 m, en Ariège.

— H. cinctella (fig. 24)

Nuevas localidades : Peyrehorade (XP52, 80 m), 14.X.87, C. E. Prieto y R. Martin leg., 8 ej +

1 c; sobre zarzas y ortigas junto riachuelo.

Su area de distribuciôn comprende (Giusti y Manganelli, 1987) la Peninsula Itâlica,

Côrcega, Archipiélago Toscano, Sicilia y posiblemente Cerdena, de donde es citada por

Perjesi (1985), adamâs del sureste de Francia (Germain, 1930; Kerney et al., 1983). También

se encuentra en Viena (Austria), Torquay (Devon, Inglaterra), Dinard (Ille-et-Vilaine) y

Budapest (Biggs, 1958; Kerney et al., 1983; Perjesi, 1985) como introducciones.

En la zona de estudio présenta una distribuciôn fragmentada en dos subâreas. De un lado,

la region de Montpellier, continua con el ârea principal de distribuciôn (sureste de Francia e

Italia), y de otro las localidades citadas de Pyrénées-Atlantiques, las cuales parecen deberse a

una prospéra introducciôn. Segûn Giusti y Manganelli (1987), esta especie suele encontrarse

en areas hûmedas fuertemente humanizadas, lo que indica una susceptibilidad al transporte

pasivo, como lo apunta también su presencia en Budapest (Perjesi, 1985) y otras localidades.

Biggs (1958) sugiere que, de acuerdo con los datos de Moquin-Tandon (1855), podria haberse

extendido por el oeste de Francia durante el siglo pasado.

— H. limbata (fig. 25)

Nuevas localidades : Ver Anexo II.

Su ârea de distribuciôn comprende desde el noroeste de Francia (salvo la region de

Bretana) hasta el norte de la Peninsula Ibérica y algunas escasas localidades en el sur de

Inglaterra, donde, al parecer, ha sido introducida (Germain, 1930; Kerney et al., 1983;

Prieto, 1986).

En el ârea estudiada présenta una distribuciôn muy nitida : region pirenaica y

394

Figs. 24-25. — Areas de distribuciôn en la Peninsula Ibérica y S de Francia de las especies de Hygromia, sobre

cuadriculas UTM con puntos de 20km de lado. 24, H. gofasi sp. nov. (triângulo), H. tassyi (estrella) e H. einctella

(circulos) ; 25, H. limbata. Los simbolos vacios indican localidades bibliogrâficas, los llenos nuevas localidades y los

medio llenos, localidades bibliogrâficas y propias.

395 —

subpirenaica y Montes Vascos, desde el norte de Gerona hasta el centro de Cantabria. La

depresiôn del Ebro parece constituir el limite sur de distribuciôn de esta especie, ligada a

bosques hümedos. Las nuevas localidades confirman los datos previos y permiten precisar algo

mâs su distribuciôn. Asi, H. limbata aparece de forma continua en el norte peninsular,

desapareciendo paulatinamente hacia el oeste en la region central de Cantabria, donde parece

ser sustituida por M. brigantina. También falta del centro y este de Burgos, asi como de la

mitad sur de Alava y Navarra, salvo por su presencia en algunas localidades aisladas situadas

en lugares altos como las sierras de Cantabria y de Codés en Alava y Navarra ; las localidades

riojanas, en la Sierra de la Demanda, podrian constituir un enclave aislado. En Huesca, segûn

material propio, H. limbata ocupa ünicamente localidades de altitud superior a los 1000 m, y

hacia el este se restringe igualmente a las âreas montanosas faltando en el valle del Segre y en

el litoral catalan. En Cataluna pénétra hacia el sur siguiendo las estribaciones de la Sierra de

Montseny.

En la vertiente francesa de Pirineos parece una especie muy comün; mâs al norte

disminuye la densidad de localidades (con falta compléta de datos para Landes y mitad

occidental de Gers) ; en el extremo oriental de Pirineos, pénétra hacia Aude hasta los Montes

Corbières, faltando al norte (region de Carcassonne) y al sur (Canigou y valle del Tech). Una

actualizaciôn de la informaciôn corolôgica con recolecciones intensivas parece urgente, ya que

la mayor parte de las localidades del sur de Francia fueron citadas el siglo pasado.

IMPLICACIONES FUNCIONALES DEL APARATO ESTIMULADOR DE Hygromia

En H. cinctella, el saco interno ( = saco accesorio) desemboca en la parte basal interna de

un cono vaginal (fig. 16), frente a una abertura alargada que se abre al conducto vaginal,

cuyas paredes presentan numerosos pequenos pliegues que llegan hasta la desembocadura de

las glândulas mucosas (fig. 18); por otra parte, el saco externo (= saco del dardo) desemboca

en el interior de la parte media del cono vaginal, donde no hay otra abertura. En H. limbata y

H. gofasi la abertura es tan larga que sobrepasa el punto de desembocadura del saco del dardo

(figs. 10 y 20), pero funcionalmente es similar, ya que se encuentra tan fuertemente cerrada en

su parte inferior que a menudo résulta indistinguible su presencia.

Durante la côpula, el cono vaginal es evaginado al exterior junto con la papila penial

(Giusti y Manganelli, 1987) y el aparato estimulador puede entonces proyectar el dardo

(fig. 23). En este proceso, y dada la configuraciôn del aparato estimulador, la secreciôn de las

glândulas mucosas se puede expulsar por una de las dos vias posibles. La primera discurre por

la luz vaginal, y la secreciôn saldria al exterior junto a la base del cono vaginal, es decir, por

donde va a ser introducido el espermatôforo. La segunda discurre por el interior del cono

vaginal, a través de la abertura situada en su base, con salida por el orificio apical del cono

vaginal. Esto supone una via indirecta mâs elaborada ya que la secreciôn mucosa deberia

producirse antes de la côpula, ser conducida al interior del cono vaginal, almacenada en el

saco interno y finalmente proyectada al exterior, junto al dardo, por contracciôn de la

musculatura de los sacos.

Varios hechos inducen a considerar esta segunda via como mâs probable :

1. La secreciôn de las glândulas mucosas se comporta como una feromona, teniendo que

entrar en el sistema circulatorio del otro individuo, mediante el pinchazo del dardo como

— 396 —

vector, para que funcione como acortador (activador) de la côpula (Adamo y Chase, 1990). En

el caso de Hygromia, la inyecciôn de la secreciôn mucosa debe realizarse o bien por la

acanaladura présente en el dardo o, si no, debe depositarse lo mâs cerca posible de los

pinchazos producidos por el dardo; en cualquiera de los casos, la secreciôn debe pasar al

conducto interno del cono vaginal antes de la côpula. La secreciôn mucosa no parece

intervenir en la transferencia del espermatôforo (Adamo y Chase, 1990); efectivamente, la

côpula y la consiguiente transferencia del espermatôforo ocurren siempre, independientemente

de la estructura y composiciôn del aparato estimulador. Por tanto, debe desecharse la emisiôn

directa de la secreciôn mucosa por la luz vaginal en los géneros que presentan cono vaginal. En

relaciôn con esto, las glândulas mucosas persisten en grupos que han perdido el saco o los

sacos del dardo, pero no existen, sin embargo, géneros con sacos del dardo que carezcan de

glândulas anexas (salvo Circassina circassica (Mousson, 1863), segûn Schileyko (1991 : 190)).

La aplicaciôn tôpica del mucus, como indica Chung (1986, en Adamo y Chase, 1990) para

Helix , no tiene efecto en la eversiôn del genital por lo que, en los grupos sin saco del dardo, la

secreciôn mucosa debe tener otros mecanismos de actuaciôn.

2. La abertura basal del cono vaginal y el conducto existente entre la desembocadura de

los sacos carecerian de funciôn si la secreciôn glandular discurriese directamente por la luz

vaginal. Igualmente, el gran tamano y la fuerte musculatura del saco accesorio indican que se

trata de un ôrgano funcional ; en este sentido, no parece lôgica la gran variabilidad existente en

la forma, tamano y posiciôn del saco accesorio si se tratase de una estructura residual no

funcional, como sugieren Giusti y Manganelli (1989). Séria interesante la investigaciôn de la

composiciôn histoquimica de las sustancias no consolidadas que se suelen observar en el

interior del saco accesorio tras su disecciôn, para confirmar su origen en las glândulas

mucosas.

3. Los pliegues de la parte superior de la vagina, entre la desembocadura de las glândulas

mucosas y la abertura basal del cono vaginal, donde también estân présentes, parecen

estructuras destinadas a conducir las secreciones mucosas hasta el saco accesorio. Dichos

pliegues se encuentran también en géneros carentes de cono vaginal, y discurren entre la

inserciôn de las glândulas mucosas y la desembocadura de los sacos.

Implicaciones sistemâticas

En relaciôn con lo expuesto se encuentra el debate actualmente existente sobre la

interpretaciôn de las estructuras que forman el aparato estimulador de la familia Hygromiidae,

en el que se mantienen dos opiniones claramente enfrentadas, con diferentes implicaciones

filogenéticas y sistemâticas.

La posiciôn clâsica (Germain, 1930; Hesse, 1931) considéra que el saco interno, cuando

existen dos en el mismo lado de la vagina, es un saco del dardo residual. Mâs recientemente,

Schileyko (1978, 1991) y Giusti y Manganelli (1987, 1989), siguiendo esta interpretaciôn,

consideran que cuatro sacos del dardo, dos a cada lado de la vagina y provistos de dardos,

constituyen el estado plesiomôrfico del aparato estimulador de Hygromiidae, y que,

tempranamente, los sacos del dardo internos perdieron su funcionalidad quedando como sacos

residuales ; de esta estructura se derivarian los diferentes aparatos estimuladores présentes en

397 —

las subfamilias actuales. Como consecuencia, y utilizando también otros caractères, Schileyko

(1978) considéra la superfamilia Hygromioidea (con Hygromiidae ünicamente) independiente

de Helicoidea (con Helicidae, Bradybaenidae y otras), cuyo aparato estimulador primitivo

tendria una estructura radial mültiple, de Sphincterochiloidea, con un primitivo aparato

estimulador con sarcobelum, y de Helicodontoidea, con aparato estimulador compuesto por

un pequeno saco sin dardo situado en la base de la glândula mucosa unica.

La otra posiciôn es mâs reciente y ha sido propuesta y desarrollada por Nordsieck

(1987), quien considéra que el aparato estimulador plesiomôrfico de Hygromiidae estaria

constituido por dos sacos del dardo, uno a cada lado de la vagina, con sus correspondientes

sacos accesorios y haces de glândulas mucosas en posiciôn superior; los sacos accesorios

tendrian una funciôn de acumulaciôn de la secreciôn de las glândulas mucosas y de la

subsecuente eyecciôn durante la côpula. Dicho autor considéra que Hygromiidae forma un

grupo monofilético con Helicidae y Bradybaenidae y que la superfamilia Helicoidea

comprende, ademâs de las citadas, a Xanthonychidae y Sphincterochilidae.

En nuestra opinion, la hipôtesis elaborada por Schileyko (1978, 1991), carece de pruebas

que la avalen puestos que aün no se ha descrito ninguna especie de Hygromiidae con dos pares

de sacos provistos de dardos, y porque los sacos carentes de dardo, caso de estar présentes,

nunca se encuentran en la posiciôn inferior. La explicaciôn dada por Schileyko (1991 : 190) a

estas objeciones no nos parece tan obvia. La segunda hipôtesis, por el contrario, puede

sustentarse en otros datos :

1. La emisiôn de la secreciôn mucosa se efectüa de diversas formas en las familias

mencionadas, pero siempre ocurre junto al punto de actuaciôn del dardo o del sarcobelo : en

Sphincterochilidae desemboca en la base del apéndice situado en el extremo apical del aparato

estimulador atrial (Forcart, 1972); en Xanthonychidae parece haber gran variabilidad

(Nordsieck, 1987), con glândulas desembocando tanto sobre el saco del dardo ( Helmintho-

glypta, Cepolis ) como en su base (Trichodiscina, Xanthonyx)', en Bradybaenidae desemboca

directamente en un reservorio comunicado e implantado sobre el saco del dardo (Schileyko,

1978; Nordsieck, 1987); fmalmente, en Helicidae, las glândulas presentan troncos musculosos

y desembocan directamente en la base del saco del dardo, donde la secreciôn es conducida

inmediatamente por el dardo (Adamo y Chase, 1990).

2. En la familia Hygromiidae, las glândulas mucosas desembocan generalmente en la

vagina, pero existen algunas exceptiones : en Ponentina, género de posiciôn sistemâtica incierta

y que podria constituir una subfamilia propia, como propone Schileyko (1991), desembocan

en los sacos accesorios; en CaracolUna, perteneciente segûn Nordsieck (1987) a la subfamilia

Ciliellinae, la ünica glândula mucosa estâ implantada sobre la vagina, pero estâ comunicada,

mediante un conducto que discurre por la pared de la vagina, con un largo apéndice ( = saco

accesorio) insertado en el saco del dardo (Prieto et al., en prensa). Finalmente, y como ya se

ha visto, en Hygromia se da una relaciôn funcional del saco accesorio con las glândulas

mucosas. Se aprecia, por tanto, una amplia variabilidad en la estructura del saco accesorio, de

dificil explicaciôn si se tratase de un ôrgano residual carente de funciôn.

3. En la subfamilia Cochlicellinae (Hygromiidae) no existen sacos con dardo ni glândulas

mucosas sobre la vagina ; el aparato estimulador es un largo apéndice, ramificado en

Cochlicella barbara (L., 1758), formado por un tronco grueso y por una region glandular

situada en su âpice. De acuerdo con los datos anteriores, este apéndice no séria mas que un

398

saco accesorio muy modificado sobre el que se insertan una o varias glândulas mucosas.

Recientemente, Schileyko (1991) considéra que Cochlicella pertenece a una familia indépen¬

dante dentro de Helicoidea.

4. Tampoco existen sacos con dardo en la tribu Monachini (Monachinae), presentando

apéndices y glândulas mucosas, con pérdidas de diverso grado; una exception podria ser

Monacha cartusicma (O. F. Miiller, 1774), donde Giusti y Manganelli (1987) describen un

apéndice inferior (= saco externo degenerado y sin dardo) y un diverticulo superior

sacciforme (= saco interno o accesorio). La situaciôn es diferente en la tribu Euomphaliini

(Monachinae), donde no existen sacos del dardo pero si unas largas estructuras vaginales que

han sido consideradas tradicionalmente sacos del dardo degenerados : las glândulas mucosas

desembocan directamente sobre la vagina y a cierta distancia de estos apéndices.

En conclusion, es dificilmente asumible en nuestra opinion que los sacos accesorios (o

sacos internos) sean sacos del dardo degenerados ya que presentan una funciôn bien definida,

la de almacenar, y evacuar durante la côpula, la secreciôn producida en las glândulas mucosas.

Agradecimientos

Este trabajo ha sido financiado en parte por el Proyecto de Investigaciôn X-86.044 del Departamento

de Educaciôn, Universidades e Investigaciôn del Gobierno Vasco. Los autores quieren agradecer a Serge

Gofas (Paris) sus valiosas criticas sobre el manuscrito, y a Yves Finet (Genève) su amabilidad por el

envio del material tipico de H tassyi.

REFERENCIAS BIBLIOGRÂFICAS

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That Decrease Courtship Duration. J. exp. Zool., 255 : 80-87.

André, J., 1982. — Les peuplements de mollusques terrestres des formations végétales à Quercus

pubescens Willd. du Montpelliérais. Premiers résultats. Malacologia, 22 (1-2) : 483-488.

Biggs, H. E. J., 1958. — Notes on Hygromia cinctella (Draparnaud). J. Conch., 24 (5) : 177-178.

Bofill, A., y F. Haas, 1920a. - Estudi sobre la malacologia de les Vails Pirenaiques. Vail del Noguera

Pallaresa. Treb. Mus. Cienc. nat. Barcelona, 3 (10) : 105-172 + 3 pl.

Bofill, A., y F. Haas, 19206. — Estudi sobre la malacologia de les Valls Pirenaiques. Conca del

Llobregat. Treb. Mus. Cienc, nat. Barcelona, 3 (13): 381-831 + 4 pl.

Bofill, A., F. Haas y J. B. Aguilar-Amat, 1918. — Fauna malacologica del Pirineu català. I. Estudi

sobre la fauna malacolôgica de la Vall de l’Essera. Treb. Inst, calai. Hist, nat., Barcelona, 1 : 9-

110+4 pl.

Bourguignat, J. R., 1884. — Hélice nouvelle des montagnes de l’Ariège. Bull. Soc. Malac. Fr., 1 : 357-

358.

Fagot, P., 1880. Histoire malacologique des Pyrénées françaises. VI. Basses-Pyrénées. Bull. Soc. Hist,

nat. Toulouse, 14 : 286-307.

1890. — Histoire malacologique des Pyrénées françaises et espagnoles. Bull. Soc. Ramond, 25 (4) :

215-244.

— 399 —

Forcart, L., 1972. — Systematische Stellung und Unterteilung der Gattung Spliincterochila Ancey. Arch.

Moll., 102 (4-6) : 147-167.

Germain, L., 1930. — Faune de France. 21. Mollusques terrestres et fluviatiles. Lechevalier Ed., Paris.

477 pp. + 13 pl.

Giusti, F., y G. Manganelli, 1987. — Notulae malacologicae, XXXVF On some Flygromiidae

(Gastropoda : Helicoidea) living in Sardinia and in Corsica. (Studies on the Sardinian and

Corsican Malacofauna VI). Boll. Malacologico, Milano, 23 (5-8) : 123-206.

Giusti, F., y G. Manganelli, 1989. - Notulae malacologicae, XLIV. A new Hygromiidae from the

Tyrrhenian islands of Capraia and Sardinia with notes on the genera Xeromicra and Xerotricha

(Pulmonata : Helicoidea) (Studies on the Sardinian and Corsican malacofauna, VIII). Boll.

Malacologico, Milano, 25 (1-4) : 23-62.

Gould, S. J., 1977. Ontogeny and phylogeny. The Belknap Press of Harvard University Press Ed.,

Cambridge. 501 pp.

Graells, M. P., 1846. — Catâlogo de los moluscos terrestres y de agua dulce observados en Espana, y

descripciôn y notas de algunas especies nuevas o poco conocidas del mismo pais. Madrid.

Haas, F., 1929. — Fauna malacolôgica terrestre y de agua dulce de Cataluna. Treb. Mus. Cienc. nat.

Barcelona, 13 : 1-491.

Hesse, P., 1931. — Zur Anatomie und Systematik palaearktischer Stylommatophoren. Zoologica, 31

(81) : 1-118 + 16 pl.

Kerney, M. P., R. A. D. Cameron y J. H. Jungbluth, 1983. — Die Landschnecken Nord- und

Mitteleuropas. Paul Parey Ed., Hamburg u. Berlin. 384 pp. + 24 pl.

Larraz, M., M. Bech y A. Campoy, 1981. — Estudio de algunas especies de moluscos del Macizo de

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Larraz. M., y A. Campoy, 1980. — Estudio faunistico del macizo de Quinto Real. II. Moluscos

(Mollusca). Publ. Biol. Univ. Navarra , Pamplona, 3 : 1-19.

Larraz, M., y R. Jordana, 1984. — Moluscos terrestres de Navarra (Mollusca : Gastropoda) y

descripciôn de Xeroplexa blancae n. sp. (F. Helicidae). Publ. Biol. Univ. Navarra , Pamplona, 11:1-

65.

Locard, A., 1894. - Conchyliologie française. Les coquilles terrestres de France. Description des

familles, genres et espèces. J. B. Baillière et fils. Ed., Lyon et Paris. 370 pp.

Mermet, C., 1843. — Histoire des Mollusques terrestres et fluviatiles vivant dans les Pyrénées-

Occidentales. Bull. Soc. Sci. Lett. Arts, Pau : 145-240.

Moquin-Tandon, A., 1855. — Histoire Naturelle des Mollusques terrestres et fluviatiles de la France.

T. I : vii + 416 pp., t. II : 646 pp., atlas : 92 pp. + 54 pl. J. B. Baillière Ed., Paris.

Nansouty, C., 1872. Catalogue des Mollusques terrestres et fluviatiles des trois départements des

Basses-Pyrénées, des Hautes-Pyrénées et des Landes. Bull. Soc. Hist. nat. Toulouse, 6 : 76-82.

Nordsieck, H., 1987. Revision des Systems der Helicoidea (Gastropoda : Stylommatophora). Arch.

Moll., 118 (1/3) : 9-50.

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Monte Naranco (Oviedo, Asturias). Bol. Cienc. nat. IDEA, 32 : 69-90.

Perjesi, G., 1985. — Quelques contributions à la connaissance et distribution hongroise et européenne de

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Prieto, C. E., 1986. — Estudio sistemâtico y biogeogrâfico de los Helicidae sensu Zilch, 1959-60

(Gastropoda : Pulmonata : Stylommatophora) del Pais Vasco y regiones adyacentes. Tesis

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Prieto, C. E., A. I. Puente, K. Altonaga y B. J. Gomez. — Genital morphology of Caracollina lenticula

(Michaud, 1831), with a new proposal of classification of helicodontoid genera (Pulmonata :

Hygromioidea). Malacologia, 35. (En prensa)

— 400 —

Richardson, L., 1980. — Helicidae : Catalog of species. Mise. Publ. Dep. Malac. Acad. Nat. Sci.

Philadelphia, 3 : iii + 1-356 (part. 1) and iii + 357-697 (part. 2).

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(Pulmonata : Helicidae). Zool. Zh., 5! : 1129-1141. (En ruso).

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(Pulmonata). Arch. Moll., 120 (4/6) : 187-236.

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Barcelona, 2 (1) : 23-30.

Watson, H., 1919. — Notes on Hvgromia limbata (Drap.). Proc, malac. Soc. London, 13 : 120-132 +

2 pi.

ANEXO I

Recopilaciôn bibliogràfica para Hygromia ( Riedelia ) limbata (Drap., 1805)

Metodologîa : Se han recogido unicamente los trabajos con citas lo suficientemente concretas como

para poder ser representadas en coordenadas UTM ; todas las restantes (paises, provincias o

departamentos) han sido omitidas. Sôlamente se indica el epiteto especifico cuando este difiere del

actualmente vâlido. En cada localidad se indica entre paréntesis el departamento o provincia y sus

coordenadas UTM. Para las provincias espanolas se utilizan las letras de las matriculas provinciales y

para los departamentos franceses las siguientes : AR, Ariège; AU, Aude; GS, Gers; HG, Haute-

Garonne; HP, Hautes-Pyrénées; PA, Pyrénées-Atlantiques; PO, Pyrénées-Orientales; TN, Tarn.

Potiez y Michaud, 1838, Gal. Moll., cat. méthod. : Barèges (HP, BH65). Dupuy, 1843, Essay Mol.

terr. fluv. : Auch (GS, CJ03); Gimont (GS, CJ23); Lectoure (GS, CJ16); Eauze (GS, BJ56); Bivés (GS,

CJ25). Mermet, 1843, Hist. Moll. terr. fluv. Pyr.-Occ. : /. y cinctella : Parc (PA, YN19). Grateloup y

Raulin, 1855, Cat. moll. terr. fluv. : Ravin d’Ayré (HP, BH65). Moquin-Tandon, 1855, Hist. nat. Moll,

terr. fluv. France, t. II : La Preste (PO, DG59) ; Ax (AR, DH03) ; Luchon (HG, CH04) ; Barèges (HP,

BH65) ; Saint-Pé (HP, YN37); Blagnac (HG, CJ73); Muret (HG, CJ61). Mabille, 1858, J. Conchyl., 7 :

Saint-Jean-de-Luz (PA, XP00). Mabille, 1865, J. Conchyl., 13 : Bayonne, sur les bords de l’Adour (PA,

XP21). Massot, 1872, Bull. Soc. agric. scient, litt. Pyr.-Orient., 19 : Arles-sur-Tech (PO, DH70);

Serralongue (PO, DG69) ; Sorède (PO, DH90) ; Le Boulou (PO, DH80) ; Caudiès (PO, DH44) ; La Preste

(PO, DG59). Nansouty, 1872, Bull. Soc. Hist. nat. Toulouse, 6 : Bayonne (PA, XP21); Bagnères-de-

Bigorre (HP, BH67); Tarbes (HP, BH69). Fagot, 1873, Bull. Soc. Hist. nat. Toulouse, 7 : Torrent d’Aulus

(AR, CH64). Fagot, 1875, Bull. Soc. Hist. nat. Toulouse, 9: Toulouse: Pech-David (HG, CJ72);

Toulouse : rive gauche de la Garonne (HG, CJ72); Toulouse : prairie de Portet (HG, CJ72); bords du

Touch, entre Saint-Martin et Saint-Michel (HG, CJ62) ; Villemur (HG, CJ75) ; Fourquevaux (HG, CJ81).

Fagot y Nansouty, 1875, Bull. Soc. Ramond, 10 : Barèges (HP, BH65); Bagnères (HP, BH67); Saint-Pé

(HP, YN37) ; Pic d’Ayré (HP, BH65). Fischer, 1876, J. Conchyl., 24 : Vallée de Cauterets (HP, YN35);

Cirque de Gavarnie (HP, YN43). Fagot, 1877, Bull. Soc. Hist. nat. Toulouse, 11 :Petites Pyrénées (HG,

CH47). Folin y Berillon, 1877a, Bull. Soc. Borda, 2 (1) : Plateau d’Iraty (PA, XN56) ; Nivelle d’Arneguy

(PA, XN47). Folin y Berillon, 1877 b, Bull. Soc. Sci. Arts Bayonne : Bramepan (PA, XP21); /. Sarratina

y /. albina : Bramepan (PA, XP21). Fagot, 1878, Bull. Soc. Hist. nat. Toulouse, 12 : Petites Pyrénées (HG,

CH37). Dupuy, 1879, Bull. Soc. Hist. nat. Toulouse, 13 : La Preste (PO, DG59); Montagne du Bouchaner

(PO). Fagot, 1880a, Bull. Soc. agric. scient, litt. Pyr.-Orient., 24 : Torrent du Garbet (AR, CH64) ; /.

Sarratina : Vallée d’Aulus (AR, CH63). Fagot, 18806, Bull. Soc. Hist. nat. Toulouse, 14 : Ax (AR,

DH03) ; Vallée d’Aulus (AR, CH63); La Bastide-de-Sérou (AR, CH76). Fagot, 1880c, Bull. Soc. Hist,

nat. Toulouse, 14 : Plateau d’Iraty (PA, XN56); Vallée de la Nivelle d’Arneguy (PA, XN47). Fagot,

1882a, Bull Soc. Hist. nat. Toulouse, 16 : Vallée de Barèges (HP, BH65); Vallée de Cauterets (HP,

— 401

YN35). Fagot, 18826, Bull. Soc. Hist. nat. Toulouse, 16 : Pic du Gar (HG, CH 15). Locard, 1882, Prod.

Malac. Fr. : odeca : Hendaye (PA, XP00); Bayonne (PA, XP21); Hylonomia : Lourdes (HP, YN47); /.

inumbilicata : La Preste (PO, DG59). Bofill, 1884, Crôn. Cient., Barcelona, 7 (162) : Ribas (GE, DG38);

entre los establecimientos de Parramon y de Montagut (GE, DG38) ; Camprodôn (GE, DG48) ; La Preste

(PO, DG59); Vilaller (L, CH10). Bourguignat, 1884, Bull. Soc. Malac. Fr., 1 : /. inumbilicata : La Preste

(PO, DG59). Gourdon, 1887, Bull. Soc. Ramond, 22 : hylonomia : Azet (HP, BH84); entre Saint-Lary et

le Ruadet (HP, BH74); Val de Moudang (HP, BH71); odeca : entre Saint-Lary et le Ruadet (HP, BH74).

Fagot, 1887a, Crôn. Cient., Barcelona, 10 (212) : hylonomia : Desde el Hospicio de Venasque à Campo

(HU, BH90); Lourdes (HP, YN47); Castejôn de Sos (HU, BH90); odeca : Castejôn de Sos (HU, BH90).

Fagot, 18876, Crôn. Cient., Barcelona, 10 (222) : odeca : Valle de Arân (L, CH13); Toulouse (HG,

CJ72); hylonomia : Valle de Arân (L, CH 13); /. : Castres (TN, DJ32). Salvana, 1888, An. Soc. Esp. Hist,

nat., 17 : hylonomia : Castellfollit (GE, DG67) ; Santa Magdalena de Puigsacâu (GE, DG67). Fagot,

1889, Crôn. Cient., Barcelona, 12 : hylonomia y odeca : Valle de Ezca (NA, XN63); Valle de Salazar (NA,

XN53). Gourdon, 1889, Bull. Soc. Malac. Fr., 6 : hylonomia : Région de las Paules (HU, CH00); Pentes

occidentales de la Sierra de Santa-Lucia (HU, CHÔO) ; Haute région de ITsabena (HU, CH00). Fagot,

1890, Crôn. Cient., Barcelona, 13 (298) : hylonomia : Parte media entre Fiscal y el hospicio de Bucharo

(HU, YN31). Bofill, 1891, Crôn. Cient., Barcelona, 14 (318) : Llavorsi, junto al Hostal del Rey (L,

CH50); Viella (L, CH 13); Betrén (L, CH22); Escunyan (L, CH22); Artias (L, CH22); Artigas de Line

(L, CH 12); Montana Pumarola (L, CH 13); Montana Piusa (L, CH 13). Fagot, 1896, Bull. Soc. Étud.

scient. Aude, 7 : hylonomia : Mont Alaric (AU, DH67); /. : Montagne-Noire (AU, DJ50); odeca : Forêt

des Fanges (AU, DH44). Maluquer, 1904, Bol. R. Soc. Esp. Hist, nat., 4 : hylonomia : Castellar d’en

Huch (B, DG 18). Fagot, 1905, Bull. Inst. Catal. Hist, nat., 9 : hylonomia : entre Saint Julià et Urgell (L,

CG79). Fagot, 1907, Bol. Soc. Arag. Cienc. nat., 6 (8-10) : hylonomia : Villaler (L, CH10); de l'hospice de

Vénasque à Campo (HU, BH90); entre Fiscal et l’hospice de Boucharo (HU, YN31); Las Paules (HU,

CH00); Pentes occidentales de la sierra Santa Lucia (HU, CH00): Panticosa (HU, YN23); odaeca :

Castejôn de Sos (HU, BH90); Astos de Vénasque (HU, BH92). Bofill, 1909, Act. Mem. I Congr. Nat

esp., Zaragoza : hylonomia : Vilaller (L, CH10); Font del Colom (L, CG16); Pont de Montanyana (HU,

CG06) ; odeca : entre Pont de Montanyana y La Agustina (HU, CG06) ; Castejôn de Sos (HU, BH90).

Maluquer, 1912, Butll. Inst. Catal. Hist, nat., 9 (4) : Vall de Ribas (GE, DG38). Aguilar-Amat, 1915,

Butll. Inst. Catal. Hist, nat., 15 : hylonomia : Camprodon (GE, DG48) ; Ribas (GE, DG38). Bofill, 1917,

Junta Cienc. nat. Barcelona : hylonomia : Camprodôn, passeig de la Font Nova (GE, DG48) ; Camprodôn

(GE, DG48); Pobla de Segur (L, CG37); odeca '. Artiga, vall d’Aràn (L, CH 12). Bofill, Haas y

Aguilar-Amat, 1918, Treb. Inst. Catal. Hist, nat., Barcelona, 1 : l. odeca : Congostos del Run (HU,

BH90); Castejôn de Sôs (HU, BH90); Benasque (HU, BH92); entre Benasque i aiguabarreig de

Vallhiberna (HU, CH02); entre el aiguabarreig de Vallhiberna i Banys de Benasque (HU, CH02); Banys

de Benasque (HU, CH02); Hospici de Benasque (HU, CH02); entre el pla dels Estanys i la Renclusa

(HU, CH02). Watson, 1919, Proc. Malac. Soc. London, 13 : Pau (PA, YN19); Salies-de-Béarn (PA,

XP61); Argelès (HP, BH77); Ciboure (PA, XP10). Bofill y Haas, 1920a, Treb. Mus. Cienc. nat.

Barcelona, 2 : l. odeca : entre La Agustina i Pont de Montanyana (L, CG 16); Font del Colom, de Pont de

Montanyana (L, CG16); Caldes de Bohi (L, CH21); Vilaller (L, CH10); Senet (L, CH11). Bofill y

Haas, 19206, Treb. Mus. Cienc. nat. Barcelona, 3 (10) : l. odeca : Pobla de Segur, en l’horta (L, CG37);

Pobla de Segur, cami de la Riba (L, CG37) ; Collegats (L, CG38) ; Llavorsi (L, CH50) ; entre Esterri i Isil

(L, CH42); entre Isil i Escala Alta (L, CH42). Bofill y FIaas, 1920c, Treb. Mus. Cienc. nat. Barcelona, 3

(12) : /. odeca : entre Seu d’Urgell i Sant Julià de Lôria (AN, CG79); Sant Julià de Lôria (AN, CH70).

Bofill y Haas, 19204, Treb. Mus. Cient. nat. Barcelona, 3 (13) : /. odeca : Pobla de Lillet (B, DG17).

Bofill y Haas, 1921, Treb. Mus. Cienc. nat. Barcelona, 3 (15) : /. odeca : Vall d’Aran (L, CH13); Vall del

Jueu (L, CH 13); Artiga de Lin (L, CH 12); Alta vall del Jueu, o sigui Pumerola (L, CH 13); Muntanya de

La Piusa (L, CH13); Viella (L, CH13); Vall del riu Nere (L, CH12); Betrén (L, CH22); Escunyau (L,

CH22); Arties (L, CH22); entre Arties i Salardû (L, CH22); Pujant al Port de la Bonaygua (L, CH32).

Bofill, Haas y Aguilar-Amat, 1921, Treb. Mus. Cienc. nat. Barcelona, 3 (14) : /. odeca : Girona (GE,

DG84) ; Vidrà (GE, DG46); Ripoll (GE, DG37); Gombreny, font de la Pedragosa (B, DG27);

Montgrony (B, DG27); Vall de Ribes (GE, DG38); Ribes (GE, DG38); Queralps (GE, DG38);

Camprodon (GE, DG48); Serra de Navà, prop Camprodon (GE, DG48); Setcases (GE, DG49);

Castellfullit (GE, DG67) ; Olot (GE, DG57) ; Santa Magdalena de Puigsacalm (GE, DG46) ; Collsacabra,

prop Olot (GE, DG46); Pla Traver, prop Olot (GE, DG57); Lladô (GE, DG87). Aguilar-Amat, 1927,

— 402 —

Butll. Inst. Catal. Hist, nat., 7 (6) : l. odeca : Montesquiu (B, DG36); Llaers, Bufadors de Babi (GE,

DG36); Bellmunt (B, DG46); Ciuret (GE, DG46) ; Pla Traver (GE, DG57). Aguilar-Amat, 1929, Butll

Inst. Catal. Hist, nat., 9 (6) : edeca (sic) : San Juan de las Abadesas (GE, DG47); Rocabruna (GE,

DG58). Haas, 1929, Mem. R. Soc. Esp. Hist, nat., 15 : odeca : Andoain (SS, WN78). Germain, 1930,

Faune France : Saint-Jean-de-Luz (PA, XP00). O. Zarate y O. Zarate, 1949, Bol. R. Soc. Esp. Hist, nat.,

47 : Bilbao, Pena de Orduna (BI, VN95) ; Guefies (BI, VN98) ; Santurce (BI, VN99) ; Zarauz (SS, WN69) ;

Zumaya (SS, WN69); Macizo del Gorbea : Villaro (BI, WN17); Santuario de Arânzazu (SS, WN45);

Monte Alonah (SS, WN46); Vergara (SS, WN47); Balneario de Alzola (SS, WN48); Deva (SS, WN59);

Zumârraga-Aizpuruchu (SS, WN57); Cestona (SS, WN68); Zarauz-Guetaria (SS, WN69); San

Sebastian : Parque Cristina Enea (SS, WN89); Valle del Baztân (NA, XN18); Roncesvalles (NA, XN36);

Ermita de San Miguel in excelsis (NA, WN85); /. hylonomia : Valle del Ezca (NA, XN52); Valle del

Salazar (NA, XN42) ; /. odeca : Valle del Ezca (NA, XN52) ; Valle del Salazar (NA, XN42) ; San

Sebastian (SS, WN89). Vilella, 1965, Mise. Zool., Barcelona, 2 : cinctella : Areo (L, CH61).

Gittenberger, 1968, Bol. Soc. Hist. nat. Baléares, 14 : Défilé de Pierre-Lys (AU, DH34). Altimira y

Balcells, 1972, Pirineos, Jaca, 104 : odeca : El Boalar (HU, XN91); San Juan de la Pena : Monte Pano

(HU, XN90) ; San Juan de la Pena : monasterio viejo (HU, XN90) ; Santa Cruz de la Serôs : El Cubilar

(HU, XN91) ; San Juan de la Pena : Collada de El Maqui (HU, XN80) ; Aranones (HU, YN03) ; Selva de

Oza (HU, XN84); Zuriza (HU, XN74); Barranco de Bujaruelo (HU, YN33). Schileyko, 1972, Zool.

Zhurnal., 51 (8) (en ruso) : Moulis (AR, CH45); Saint-Girons (AR, CH46) ; Castillon : Monrojo (HP,

CH35). Sacchi, 1979, Boll. Mus. Civ. Venezia, 30 : Jaca, fondovalle del Rio Aragon (HU, YN01); Prati a

sud della città di Jaca (HU, XN91). Fernandez, 1980, Bol. R. Soc. Esp. Hist. nat. (Biol.), 78 : odeca :

Collsacabra (B, DG46). Marcuzzi y Biondi, 1980, Bull. Cent. Étud. Rech. scient., Biarritz, 13 (1) :

Bayonne (PA, XP21). Larraz y Campoy, 1980, Publ. Biol. Univ. Navarra, Pamplona, 3 : cinctella :

Macizo de Quinto Real (NA, XN26). Altonaga y Gomez, 1981, Elhuyar, San Sebastian, 7 (4) : Iso (NA,

XN42); Usun (NA, XN42); Arbaiungo arroila (NA, XN42). Larraz, Bech y Campoy, 1981, Munibe,

San Sebastian, 33 (1-2) : cinctella : Macizo de Quinto Real (NA, XN26). Bech y Fernandez, 1982, La

Veu de Tona, 30 : odeca : Tona (B, DG33). Larraz y Jordana, 1984, Publ. Biol. Univ. Navarra,

Pamplona, 11 : Iribas (NA, WN86); Echauri (NA, WN93); Urriza (NA, WN95); Beunza (NA, XN05);

Aralar (NA, WN86) ; Leurza (NA, XN06) ; Urbasa (NA, WN64) ; Orhy (NA, XN66) ; Ezcurra (NA,

WN97) ; Santesteban (NA, XN07) ; Minchate (NA, XN65) ; Lôquiz (NA, WN63) ; Zugarramurdi (NA,

XN19); El Perdôn (NA, XN03); Irurzun (NA, WN95); Uztarroz (NA, XN65) ; Orbaiceta (NA, XN46);

Loiti (NA, XN32) ; Izaga (NA, XN23) ; Oroquieta (NA, XN06) ; Ituren-Zubieta (NA, XN07) ; Aoiz (NA,

XN33) ; Irati (NA, XN56) ; Quinto Real (NA, XN26) ; Elizondo (NA, XN27) ; Roncesvalles (NA, XN36).

Fernandez, 1985, Bol. R. Soc. Esp. Hist. nat. (Biol.), 80 (3-4) (1982) : Font de l’Atalaya, St. Boi de

Lluçanès (B, DG25); Font de les Coves, Prats de Lluçanès (B, DG 15). Ramos y Aparicio, 1985, Malac.

Rev., 18 : Los Pandos (S, VN27); Santander, Cobanera city district (S, VP31). Giusti y Manganelli,

1987, Boll. Malac., Milano, 23 (5-8) : Macizo de Gorbea, S. of Arraba (BI, WN16). Ojea, Rallo y

Iturrondobeitia, 1987, Kobie, Bilbao, 16 : entre Gôrliz, Arminza y Urdüliz (BI, WP00); Orduna (VI,

VN95).

ANEXO II

Lista de localidades de Hygromia (Riedelia) limbata (Drap., 1805)

Las fechas de recolecciôn, los recolectores y el material recogido se han omitido y las coordenadas

UTM se han abreviado. Todo el material estudiado se encuentra en la colecciôn de Malacologia de la

UPV/EHU.

Alava : Altube, WN15; Angosto, VN94; Ailés, VN86; Aramayona : Ibarra, WN36; Atauri, WN43 ;

Bajauri, WN32; Délica : canon rio Nerviôn, WN05; Fuente Los Chorros, WN23; Gurendes, VN94;

Ibarra/Mondragôn : 2 km, WN36; Murguia : rio Bayas, WN15; Orduna : Pico del Fraile, VN95 ; Osma :

Valderono, VN94; Ribera, VN84; Santa Cruz de Campezo, WN52; Sarria : puente Blanco, WN15;

- 403 —

Sierra Salvada, VN96; Subijana : desfiladero, WN04; Valderejo, VN84; Zârate, WN15. Burgos :

Bârcenas, VN57; Espinosa de los Monteras, VN56; Estacas de Trueba, VN47; Hayal de Santiago,

WN05; Horadada, La : sedim.?, VN63; Mercadillo de Mena, VN77 ; Montes de Orduiïa : Txarlazo,

VN95 ; Peiïa de Orduna, VN95 ; Quintana Entreprenas : sedim, VN74 ; San Zadornil, YN84 ; Siones,

VN76; Villabasil, VN76; Villafria, VN84; Villalba de Losa : Txolope, VN95; Villasana de Mena, VN77;

Villasante de Montija/Colina, VN66. Cantabria : Agüera, VN79; Alceda, VN28; Arredondo, VN59;

Bustablado, VN49; Cotillo, VN18; Entrambasaguas, VP40; Hazas/Asôn, VN58; Isla, VP51 ; Llaguno,

VN79; Pena Cabarga, VP30; Puente Viesgo, VN29; Pujayo, VN17; San Român, VP31 ; Sel de la Pena,

VN27; Sierra de Ibio, VN09; Valle Asôn, VN58; Vega de Pas : Candolias, VN37; Villacarriedo, VN38.

Gers: Beaulieu, CJ03; Masseube/Auch, CJ01 ; Miélan/Tillac, BJ81 ; Mirande, BJ92. Guipuzcoa :

Aitzgorri : 2km S, WN55; Aitzgorri : Campa de Urbia, WN55; Aizarna : 3 km, WN68; Albistur,

WN77; Alkiza, WN78; Alto de Itziar, WN59; Aralar : Oidui, WN76; Arantzazu, WN45; Aritzalde,

WN55; Arzallus, WN68; Ataun : San Martin, WN66; Bedayo, WN76; Bengoetxea, WN56; Cerain,

WN56; Cestona, WN68; Hernialde, WN77; Motrico, WN59; Ojarbi, WN66; Onate, WN46; Otzaurte,

WN57; Pena Madariaga, WN58; Régil, WN67 ; San Miguel de Artadi, WN69; San Sebastian : Urgull,

Alza y Gladys Enea, WN89; Tolosa, WN77. Haute-Garonne : Astau, BH93; Superbagnères, CH03.

Hautes-Pyrénées: Bagnères-de-Bigorre/Gerde, BH67; Bareilles, BH95; Betpouey, BH55; Cadéac/

Gouaux, BH85; Cauterets : N, YN35; Ost, YN36; Pont de Prat, BH83; Pragnères, BH54; Prat/Lahitte,

BH87 ; Sarrancolin, BH86 ; Saint-Lézer, BJ60 ; Saint-Pé-de-Bigorre, YN37 ; Tournay, BH78 ; Vialette, La,

BH66. Huesca : Ansô : 3 km N, XN73 ; Bielsa : embalse de Pineta, BH72 ; Bujaruelo, YN32 ; Candanchü,

YN03; Castarnes : cruce, CH10; Formigal, YN13; Obarra, CG09; Panticosa, YN23 ; Piedrafita de Jaca,

YN13; Pineta : parador, BH62; Plan de Escün, Garganta, BH71; Plan : puente de la Fonde, BH82;

Pueyo de Jaca, YN23; Salient de Gâllego, YN13; San Juan de la Pena, y monasterio viejo, XN90; Selva

de Oza : Boca del Infierno, XN84 ; Sigués : puente rio Ezca, XN62 ; Siresa, XN83 ; Urdués : 1 km, XN83 ;

Villanüa, YN02. La Rioja : Ezcaray, VM98 ; Leiva, VN90; Monte Tolono, junto Labastida, WN11;

Posadas, VM97; San Millân de la Cogolla, WM 18; Villanueva de Cameras, WN26. Navarra : Alii :

aired, cueva Akelar, WN96; Aralar : Altxueta y Casa Forestal, WN85; Arteta, WN94; Atondo, WN94;

Baraibar, WN86 ; Ciordia, WN64 ; Elizondo, XN27 ; Endarlaza, XN09 ; Etxalar, XN18 ; Foz de Arbayün,

XN42; Foz de Minchate, XN65; Huarte Araquil, WN84; Irati, XN56; Iribas : rio Ercilla, WN86;

Iribas : nacedero rio Ercilla, WN85; Irurzun : Monte Erga, WN95; Isaba, XN64; Ispegui, WN28 ;

Madoz, WN95; Monreal, XN22; Nuestra Senora del Camino, XN63; Ochagavia, XN55; Olazagutia,

WN64 ; Orbaiceta, XN45 ; Puerto de Otsondo, XN28 ; Rincôn de Belagua, XN75 ; Roncesvalles, XN36 ;

Santesteban, XN07 ; Unzué, XN12; Urbasa : km 28, WN64; Urdax, XN29; Urzainki : 1 km N, XN64;

Usateguieta, WN97 ; Ustarroz, XN65 ; Usün, XN42 ; Valle del Roncal : entrada, XN62 ; Vera de Bidasoa,

XN09; Yanci, XN08. Pyrénées-Atlantiques: Arette, XN87; Arthez-de-Béarn, XP91; Arthez-d’Asson,

YN27 ; Arudy, YN07 ; Atarratze, XN77 ; Atherey, XN77 ; Aydius, YN06 ; Barkoxe, XN88 ; Bedous,

XN96; Bidarrai, XN39; Bioux-Artigues, YN04; Bosque de Sansanet, XN94; Cambô, XP20; Camou-

Cihigue, XN77; Castet, YN17; Col d’Osquich, XN68; Corne/Ger, YN39; Corolotz, XP40; Chibaucoa,

XP10; Donibane Garazi, XN48; Eaux-Bonnes, YN16; Eaux-Chaudes, YN05; Escot, XN97 ; Gabas,

YN05; Gelos, YN19; Gorges de Kakouetta, XN76; Gourette, YN15; Holkarte : Gorges de H.-Oladubi,

XN66; Irisarry, XN49; Issor, XN97 ; Isturitz-Oxocelaya, XP40; Ithurraldia, XN48; Itsasu, XN29;

Larrau : puerto, XN66; Leorlas/Urdax, XN29; Lescun, XN95; Lons, YP10; Louhossoa, XN39;

Mauleon, XN78; Muskildi, XN68; Peyrehorade, XP52; Pic de Gillers, XN86; Portalet : fuerte, YN14;

Puerto de Escale : N, XN94; Saint-Jean-le-Vieux, XN48; Sare, XNI9; Sainte-Engrâce, XN86; Sainte-

Engrâce : presa, XN76; Saint-Martin, XP60; Suhare, XN67; Urdos : central eléctrica, XN95; Urgazieta,

XP31 ; Ustaritz, XP20; Zelai, XP30. Vizcaya : Acorda, WP20; Aldeacueva, VN68; Anboto : Campa de

Larrano y aired. Galtzaikoba, WN37 ; Arcentales : La Toba, VN89 ; Areta/Bengoechea, WN07 ;

Arminza, WP00; Aspilza, WN49; Atxarte, WN37; Axpe-Busturia, WP20; Basinagre : aired, cueva La

Mora, VN79; Bérriz, WN38 ; Bilbao : Altamira, Arabella y Txurdinaga, WN09; Cadena, La : Pico del

Moro, Ventalaperra y aired, cueva Teleférico, VN68 ; Calera del Prado, La, VN67 ; Canala, WP20;

Ceânuri, WN27; Ceberio : Ermitabarri, WN17; Ciérvana, VN99; Dima : entrada cueva Barronbarro II,

WN27 ; Ereno, WP30 ; Galdames : aired, cueva 6.G.74, aired, cueva Los Cuervos y montes, VN99 ;

Gardata, WP30; Gorbea : Aldaminape, Arraba, Itxina, Lekanda, Ojo Atxular, Paraiso de Arraba, Paso

de Aldape, Paso de Mandabide, Rio Padrobaso, Rio Zubizola y Yondegorta, WN16; Iruzubieta, WN38 ;

Jaureguia/Ibarra, WN07 ; Lamindano, WN27 ; Lauquiniz, WN09 ; Lejona : Universidad, WN09 ;

— 404 —

Lendono de Arriba, VN96 ; Lequeitio, WP40 ; Marquina, WN49 ; Nachitua, WP30 ; Orduna : subida a la

Virgen, VN96; Pagasarri : 2 km del refugio y San Roque, WN08; Portuondo, WP20; Regato, El, y

pantano superior, VN99; San Pedro de Atxerre, WP20; San Pedro de Galdames, VN98; Santa Agueda,

VN98; Tellitu, VN98; Traslavina : apeadero, VN88; Treto, VN68; Trucios : Barranco de Laguanaz,

VN89; Ubidea, WN26; Untzillaitz, WN27 ; Urkizu, y aired, cueva Otxas y aired, cueva Usumaltxe,

WN18; Yurre, WN17; Zabalandi : hayedo, WN37; Zaramillo : aired, mina. VN98; Zolarte, WN39.

Bull. Mus. natl. Hist, nat., Paris, 4 e sér., 14 , 1992,

section A, n° 2 : 405-441.

Antarctic and Subantarctic echinoids

from ‘Marion Dufresne’ expeditions MD03, MD04, MD08

and from the ‘Polarstern’ expedition Epos III

by Chantal De Ridder, Bruno David and Alberto Larrain

Abstract. The Subantarctic and Antarctic MD03, MD04, MD08 and Epos III expeditions

collected regular and irregular echinoids from the continental shelf around Marion and Prince Edward

islands (MD08), Crozet islands (MD03, MD08), Kerguelen islands (MD03, MD04), and the Weddell Sea

(Epos III). The collection comprises 31 species belonging to 6 families. Affinities and taxonomic position

of 18 species or subspecies are discussed : Aporocidaris antarctica, Ctenocidaris nutrix nutrix, C. nutrix

longispina, C. perrieri, C. speciosa, C. spinosa, Homalocidaris gigantea, Notocidaris mortenseni, N.

gaussensis, Kamptosoma asterias, Sterechinus diadema, Plexechinus planus, P. aff. cinctus, Pourtalesia aff.

hispida, Amphipneustes rostratus, Brachysternaster chesheri, Parapneusles abaloides and Delopatagus

brucei. Geographical and bathymetrical distributions for all species are investigated and tabulated.

Résumé. — Les échinides réguliers et irréguliers récoltés lors des expéditions subantarctiques et

antarctiques MD03, MD04, MD08 et Epos III sont déterminés. Les récoltes ont été effectuées sur le

plateau continental autour des îles Marion et Prince Edward (MD08), Crozet (MD03, MD08), Kerguelen

(MD03, MD04), et dans la mer de Weddell (Epos III). La collection comprend 31 espèces appartenant à

6 familles. Les affinités et la position taxonomique de 18 espèces ou sous-espèces sont discutées :

Aporocidaris antarctica, Ctenocidaris nutrix nutrix, C. nutrix longispina, C. perrieri, C. speciosa, C, spinosa,

Homalocidaris gigantea, Notocidaris mortenseni, N. gaussensis, Kamptosoma asterias, Sterechinus diadema,

Plexechinus planus, P. aff. cinctus, Pourtalesia aff. hispida, Amphipneustes rostratus, Brachysternaster

chesheri, Parapneustes abatoides and Delopatagus brucei. Les distributions géographique et bathymétrique

de toutes les espèces sont détaillées.

C. De Ridder, Laboratoire de Biologie marine, Université Libre de Bruxelles, Belgium.

B. David, Paléontologie analytique, URA CNRS 157, Université de Bourgogne, France.

A. Larrain, Laboraiorio de Zoologia, Universidad de Concepcion, Chile.

Introduction

Bionomical investigations have been made in the Antarctic and Subantarctic regions by

several recent expeditions (fig. 1). The MS “ Marion-Dufresne ” expeditions MD03, MD04,

MD08, organized by the “Terres Australes et Antarctiques Françaises” (TAAF), investigated

the continental shelf and slope of some Subantarctic islands, namely Kerguelen (MD03 and

MD04 in 1974 and 1975, respectively), Crozet (MD03 and MD08 in 1974 and 1979,

respectively), Marion and Prince Edward (MD08 in 1979). Two additional sets of data were

obtained for Kerguelen (Golfe du Morbihan et Golfe des Baleiniers) by the “Japonaise”

406 —

collections Ker72 and Ker74. The MS “ Polarstern ” expedition Epos III studied the Weddell

Sea. This last expedition was sponsored by the European Science Foundation and by the

“ Alfred Wegener Institüt ” (AWI) for polar and marine research ; the material was sorted by

the “Centre National de Tri et d’Océanographie Biologique” (CENTOB, IFREMER). One of

the aims of these expeditions was a quantitative and qualitative inventory of the benthos.

Details of the program, stations, sampling methods and environmental (physical and chemical)

conditions are given by Hureau (1976) for MD03, by Guille (1977a) for MD04, Ker72 and

Ker74, by Arnaud and Hureau (1979) for MD08, by Arntz et al. (1990) for Epos III. The

study area is mapped in figure 1. The echinoid collections are deposited at the Muséum

national d'Histoire naturelle in Paris.

Fig. 1. — Areas prospected during the expeditions MD03, MD04, MD08, Ker72-74, and Epos III.

RESULTS

31 species of echinoids were collected in the Antarctic and Subantarctic regions during the

MD03, MD04, MD08, “Japonaise” Ker72 and Ker74, and Epos III expeditions. They belong

to 6 families : Cidaridae, Echinothuriidae, Echinidae, Urechinidae, Pourtalesiidae and Schizas-

teridae. The species and their collecting stations are listed for each expedition (see tables 1-5);

their geographical (table 6) and bathymetric (fig. 5) distributions are also summarized. Species

presenting taxonomic difficulties, or those rarely collected and in need of further description

and illustration are discussed individually below. For the other species listed, please refer to

Mortensen (19286, 1935, 1943, 19506, 1951) for more information. Brachysternaster chesheri,

Plexechinus planus and Urechinus mortenseni were described subsequent to Mortensen’s

monograph, see Larrain (1985), Mironov (1978) and David & Mooi (1990), respectively.

— 407

Table 1. — Inventories of the collected species and lists of stations of expedition MD03 at Kerguelen

and Crozet islands (asterisks indicate that a part of the sample corresponds to broken specimens or

fragments).

Station Long.

Lat.

Depth

Number

of specimens

ClDARIDAE

Aporocidaris antarctica

St.

65°39'9 E

50°49'1 S

3240 m

Ctenocidaris nutrix nutrix

St.

70°44'7 E

49°30'7 S

115m

St.

70°47T E

49°33'2S

130m

St.

71°51'7E

49°25'4S

650-620 m

St.

75°38'4E

52°12'7 S

560-525 m

St.

64°57'9 E

49°48'4S

250 m

St.

64°50'6 E

49°45'8 S

262 m

St.

66°04'0 E

47°24'9 S

585 m

St.

70°51'1 E

48°58'5 S

105-90 m

St.

70°01’9E

49°59'2 S

158 m

St.

69°48'7 E

50°10'7S

195m

Echinothuriidae

Kamptosoma asterias

St.

69°35'7 E

55°49'5S

4200-4225 m

Echinidae

Sterechinus neumayeri

St.

70°47T E

49°33'2S

130m

St.

73°42'0 E

52°58'0S

123 m

St.

64°57'9 E

49°48'4 S

250 m

St.

64°50'6E

49°45'8 S

262 m

St.

68°07TE

47°42'2S

243 m

St.

70°55'4 E

48°29'7 S

360-345 m

21*

St.

70°51'1 E

48°58'5 S

105-90 m

94*

St.

70°01'9 E

49°59'2 S

158 m

St.

69°48'7 E

50°10'7 S

195 m

19*

St.

51°59'0 E

46°24'0 S

180m

St.

51°58'3 E

46°23'3 S

165 m

St.

51°29'0E

46°18T S

400 m

St.

50°50'2 E

46°02'3 S

187m

St.

50°32'8 E

45°57'2S

110m

Urf.chinidae

Plexechinus aff. cinctus

St.

66°04'0 E

47°24'9 S

585 m

- 408

POURTALESIIDAE

Pourtalesia cf. hispida

St. 12

69°35'7 E

55°49'5 S

4200-4225 m

1 *

St. 13

65°39'9 E

50°49T S

3240 m

6 *

SCHIZASTERIDAE

Abatus cordatus

St. 7

75°38'4E

52°12'7 S

560-525 m

St. 8

73°42'0E

52°58'0S

123 m

St. 8

73°38'0E

52°59'4S

90 m

St. 10

72°50T E

53°06'7 S

255 m

1 *

St. 17

66°04'0 E

47°24'9 S

585 m

1 *

Brisaster kerguelensis

St. 3

71°51'7E

49°25'4 S

650-620 m

16*

St. 6

71°35'8 E

50°37'9 S

565 m

1 *

St. 7

75°38'4 E

52°12'7 S

560-525 m

1 *

St. 17

66°04'0 E

47°24'9 S

585 m

1 *

St. 18

68°07T E

47°42'2 S

243 m

Table 2. — Inventories of the collected species and lists of stations of expedition MD04 at Kerguelen

islands (the precise depths of stations 105 to 107 are unknown).

Station Long. Lat. Depth „

& of specimens

ClDARIDAE

Ctenocidaris nutrix nutrix

St. 2

70°22'2 E

49°29'3 S

44 m

St. 3

70°33'2E

49°28'8 S

75m

St. 4

70°40'5 E

49°29'8 S

96 m

St. 5

70°56'0 E

49°30'0 S

147 m

4 *

St. 5

70°54'5 E

49°30'6S

140 m

St. 7

70°57'0 E

49°32'1 S

149-155 m

St. 14

69°44'6 E

49°44'4 S

103 m

St. 15

69°47'2 E

49°54'8 S

120 m

St. 16

69°49'2 E

50°02'7 S

166 m

St. 21

69°18'3 E

49°41'4S

110 m

1 *

St. 23

68°48'5 E

49°55'5 S

155m

St. 24

68°29'0E

50°04'0 S

195m

St. 25

68°17'2E

50°08'8 S

255 m

St. 26

68°28'3 E

50°03'4 S

192-198m

St. 26

68°25'0E

50°05'8 S

207 m

50*

St. 34

68°10'7E

49°27'4S

185m

St. 35

67°53T E

49°28'0S

191m

St. 37

67°19'9E

49°26'5 S

301m

St. 44

68°03'5 E

49°04'0 S

175-192m

St. 45

67°30'4E

49°00'3 S

206 m

— 409 -

St. 47

67°07'9 E

48°59'1 S

315m

St. 51

68°45'1 E

48°44'0 S

95 m

St. 52

68°31'2E

48°37'2S

125m

St. 57

67°32'5 E

48°07'0 S

365 m

St. 65

69°04'0 E

48°01'0 S

177 m

St. 101

70°45'6E

49°03'4 S

84 m

St. 102

70°50'8 E

48°56'6S

95 m

St. 108

70°41'3E

49°03'4 S

76m

St. 113

70°19'8 E

49°51'0S

145 m

rad.

St. 114

70°24'4 E

49°54'5 S

168 m

St. 116

70°34'6 E

50°02'0 S

346 m

St. 118

70°28'7 E

49°58'6S

245-185 m

St. 119

70°19'0E

49°49'9 S

131 m

Echinidae

Sterechinus neumayeri

St. 3

70°33'2 E

49°28'8 S

75m

St. 5

70°54'5 E

49°30'6 S

140 m

St. 8

69°38'3 E

49°31'2S

21 m

St. 8

69°38'3 E

49°31'2S

22 m

St. 9

69°39'4 E

49°32'2 S

110m

St. 10

69°40'8 E

49°33'2S

49 m

St. 14

69°44'6 E

49°44'4 S

103 m

St. 15

69°47'2 E

49°54'8 S

120 m

St. 23

68°48'5 E

49°55'5 S

155 m

St. 24

68°29'0 E

50°04'0 S

195m

St. 26

68°25'0 E

50°05'8 S

207 m

37*

St. 27

69°14'0 E

49°32'9 S

176-170m

St. 47

67°07'9 E

48°59'1 S

315m

St. 48

67°17'6E

49°00'4 S

239 m

St. 52

68°31'2E

48°37'2S

125 m

St. 59

68°38'6E

48°41'4S

104 m

St. 62

69° 11'6E

48°40'1 S

75 m

St. 62

69°11'3E

48°40'6 S

61 m

St. 70

68°56'5 E

47°42'2 S

204 m

St. 72

69°12'0E

48°46'6S

57 m

St. 74

69°01'1 E

49°02'3 S

30 m

St. 75

69°08'0 E

48°58'1 S

211m

St. 76

69°08'0 E

48°54'6S

125-89 m

St. 77

69°10'5 E

48°51'3S

190m

St. 78

69°12'3 E

48°45'7 S

46-54 m

St. 79

69°21'3 E

49°04'0 S

37 m

St. 84

69°56'5 E

49°08'3 S

50 m

St. 88

69°59'3 E

48°54'6S

87 m

St. 90

70°09'0 E

48°20'9 S

128m

St. 91

70°14'0E

48°02'0 S

151 m

St. 93

70°15'7 E

47°44'8 S

164-162 m

St. 108

70°41'3 E

49°03'4S

76 m

St. 113

70°21'2E

49°50'2S

147 m

St. 113

70°19'8 E

49°51'0S

145m

frag.

St. 114

70°24'4 E

49°54'5 S

168 m

St. 118

70°28'7 E

49°58'6S

245-185 m

St. 119

70°19'0E

49°49'9 S

131 m

— 410 -

POURT ALESIID AE

Pourtalesia sp.

St.

68°25'0 E

50°05'8 S

207 m

St.

67°32'5 E

48°07'0 S

SCHIZASTERIDAE

Abatus cordatus

365 m

frag.

St.

70°54'5E

49°30'6S

140 m

St.

69°38'3 E

49°31'2 S

21 m

St.

69°38'3 E

49°31'2S

22 m

St.

69°39'4E

49°32'2S

110m

St.

69°40'8 E

49°33'2 S

58 m

St.

69 “40'8 E

49°33'2S

49 m

St.

69°40'3E

49°39'8 S

36 m

St.

69°43'3 E

49°41'3 S

72 m

St.

69°20'4 E

49°35'4S

21 m

22*

St.

69°20'5 E

49°35'2 S

18 m

St.

69°20'5 E

49°35'2 S

19m

St.

69°20'5E

49°36'0S

67 m

14*

St.

69°20'7 E

49°36'1 S

70 m

St.

68°48'5 E

49°55'5 S

155 m

St.

68°50'l E

49°27'7 S

35 m

St.

68°46'8 E

49°27'4 S

63 m

15*

St.

68°46'5 E

49°27'3 S

68 m

St.

68°47'5 E

49°09'3 S

140 m

St.

68°52'2E

48°48'4S

60 m

St.

68°52'2E

48°48'2 S

65 m

St.

68°31'2E

48°37'2S

125 m

St.

67°53'1 E

48°19'7 S

185m

St.

69°02'2 E

48°41'0 S

18m

St.

69°02'2 E

48°41'0S

17m

10*

St.

69°03'5 E

48°40'5 S

51 m

St.

69“03'5 E

48°40'4 S

48 m

St.

69°04'0 E

49°06'3 S

35 m

St.

69°04'0 E

49°06'3 S

30 m

St.

69 o 01'l E

49°02'3 S

31 m

St.

69°01 '1 E

49°02'3 S

30 m

St.

69°08'0 E

48°54'6 S

125-89 m

St.

69°21'3 E

49“04'0 S

43 m

St.

69°21'3 E

49°04'0 S

37 m

St.

69°3 1 ' 1 E

48°55'4S

209-305m

St.

69°55'6 E

49°10'9 S

24 m

73*

St.

69°58'0 E

49°02'9 S

95 m

St.

70°09'0 E

48°20'9 S

128 m

St.

100

70°40'5 E

49°03'6 S

74 m

St.

110

70°34'0 E

49°10'0S

18 m

17*

St.

110

70°34'0 E

49°10'0S

22 m

38*

St.

113

70°19'8 E

49°51'0 S

145 m

frag.

St.

121

70°08'1 E

49°41'8 S

16-17 m

— 411

Brisaster kerguelensis

St.

68°25'0 E

50°05'8 S

207 m

St.

68°58'5 E

47°41'5 S

200 m

St.

68°56'5 E

47°42'2S

204 m

St.

69°08'0 E

48°54'6S

125-89 m

St.

70°04'7 E

48°38'1 S

105m

St.

70°06'0E

48°38'0S

105 m

St.

70°09'0E

48°19'3 S

128 m

St.

70°15'7E

47°44'8 S

164 m

St.

70°15'8 E

47°44'9 S

164 m

St.

70°15'7E

47°44'8 S

164-162 m

St.

70°23'8 E

47°26'5S

170m

33*

St.

70°27'5 E

47°09'7 S

188m

St.

70°30'2 E

46°47'7 S

1218m

St.

105

71°06'5 E

48°43'9S

frag.

St.

106

71°06'5 E

48°43'5 S

St.

107

71 ° 18'5 E

48°32'3 S

frag.

St.

115

70°29T E

49°58'0S

234 m

Table 3. — Inventories of the collected species and lists of stations of expedition MD08 at Marion,

Prince Edward and Crozet islands.

Station

Long. Lat.

Depth

Number

of specimens

Echinidae

Sterechinus neumayeri

St. 9

51°50'5E

46°22'8 S

75-104m

St. 9

51°49'6E

46°10'8 S

120-150 m

St. 9

51°54'3E

46°22'4 S

150-160m

St. 9

51°52'3E

46°19'8 S

150-340 m

St. 11

37°53'9E

46°52'2 S

115-120m

St. 12

37°54'1 E

46°55'7 S

103 m

St. 13

37°55'6E

46°56'3 S

120m

St. 15

38°00'0E

46°57'7 S

185-210m

St. 15

37°59'9 E

46°57'7 S

204 m

St. 16

37°59T E

46°50'2 S

138-142 m

St. 17

37°53'8 E

46°52'1 S

112m

St. 17

37°53'5 E

46°52'5 S

110 m

St. 18

37°56'2E

46°49'8 S

140 m

St. 18

37°56'4E

46°49'8 S

138m

St. 19

38°03'7E

46°45'9 S

190 m

St. 20

38°03'5 E

46°47'2 S

180m

St. 21

37°52'9 E

46°52'9 S

50 m

St. 21

37°52'8 E

46°53'3 S

50 m

St. 22

37°51'9 E

46°52'4S

31 m

St. 23

38°0T3 E

46°57'9 S

250-460m

St. 25

37°56'6 E

46°45'3 S

185-232m

121

St. 26

38°00'6 E

46°50'6S

135-145m

St. 28

37°57'2 E

46°43'5 S

246-285 m

— 412

St. 31

37°46'6E

46°59'5 S

185 m

St. 32

37°46'8 E

46°59'0S

83-100 m

St. 33

37°51'5E

46°52'2 S

45 m

St. 34

37°51'2E

46°50'2 S

115m

St. 34

37°51'2E

46°50'2S

110m

St. 35

38°00'3 E

46°39'7 S

53m

St. 36

38°06'7 E

46°40'7 S

570-315 m

St. 36

38°07'2E

46°40'9S

570-375 m

St. 42

51°34'9 E

46°21'4S

172-220m

St. 48

50°37'1 E

46°05'0 S

200-140 m

St. 50

50°37'8 E

45°51'5S

150 m

St. 53

50°20'6E

46°07'5 S

110m

St. 66

49°13'3 E

46°15'3 S

500-562m

St. 72

50°32'0 E

46°23'4 S

187-155 m

St. 73

50°37'8 E

46°24'3 S

263-412m

St. 74

50°47'8 E

46°17'8 S

290 m

St. 75

51°52'9 E

46°19'9 S

155-257 m

St. 75

51°52'0E

46°21'0S

145-135 m

St. 78

51°58'1 E

46°23'7 S

142-170 m

St. 79

51°53'8E

46°24'6 S

100 m

SCHIZASTERIDAE

Brisaster kerguelensis

St. 9

51°51'2E

46°22'9 S

125m

St. 40

51°33'9E

46°21'1 S

190m

St. 43

5riroE

46°18'5 S

1400-1500 m

13*

St. 44

51°14'0E

46°18'0S

1500 m

St. 46

50°44'7 E

46°10'6 S

375-390 m

10*

St. 57

50°05'3 E

45°46'2S

195-200 m

St. 59

49°59'3 E

45°59'9S

210-217m

St. 60

49°48'2E

46°02'7 S

245-250 m

St. 67

49°37'4E

46°16'8 S

277-280 m

St. 70

50°28'4E

46°46'6 S

1350-1440 m

St. 71

50°39'0E

46°37'5 S

268-270 m

St. 72

50°32'0E

46°23'4S

187-155m

Tripylaster philippi

St. 18

37°56'2 E

46°49'8 S

140 m

St. 28

37°58'4 E

46°42'6 S

257-280 m

St. 31

37°46'6E

46°59'5 S

185m

— 413 —

Table 4. — Inventories of the collected species and lists of stations of expeditions “Japonaise” 1972

& 1974 at Kerguelen islands.

Station

Depth

Number

of specimens

ClDARIDAE

Ctenocidaris nutrix

nutrix

Golfe du Morbihan (7 stations)

23-270 m

13*

Echinidae

Sterechinus neumayeri

Off Ratmanoff (1 station)

250-270 m

Golfe du Morbihan (1 station)

46 m

Golfe des Baleiniers (2 stations)

34-38 m

SCHIZASTERIDAE

Abatus cordatus

Golfe du Morbihan (82 stations)

6-175 m

94*

Golfe des Baleiniers (14 stations)

1-50 m

45*

Table 5. — Inventories of the collected species and lists of stations of expedition Epos III in the

Weddell Sea.

Station Long. Lat.

Depth

Number

of specimens

ClDARIDAE

Ctenocidaris nutrix longispina

St. 229

26°16'7 W

75°15'7 S

498 m

St. 235

27°34'7 W

75°09T S

404-407 m

St. 241

28°00'3 W

75°02'9 S

451-453 m

St. 256

27°36'4 W

75°10'9 S

399-382 m

St. 257

27°59T W

75°08'2 S

460-457 m

St. 270

20°45T W

73°21'3S

294-305 m

St. 275

12°34'7 W

71°39'5 S

301-330 m

Ctenocidaris perrieri

St.

217

46°58T W

60°37'6 S

232-239m

St.

224

13°04'2 W

71°15'8 S

185-187 m

St.

229

26°13'3 W

74°14'8 S

500-506m

St.

248

29°31'3W

74°39'9 S

593-602 m

St.

271

20°59'4 W

73°17'0S

352-399 m

St.

273

21°03'9W

73°34'8 S

193-197 m

St.

275

12°34'7 W

71°39'5 S

301-330m

St.

284

13°14'0 W

71°12'0 S

402-412 m

— 414

Ctenocidaris cf. rugosa

St.

217

46°58'1 W

60°37'6S

232-239 m

St.

250

29°39'9 W

74°35'1 S

799-810 m

Ctenocidaris speciosa

St.

217

46°58'1 W

60°37'6S

232-239 m

St.

226

25°58'3 W

75°15'9S

569-574 m

St.

229

26°16'7 W

75°15'7S

498 m

St.

248

29°31'3W

74°39'9 S

593-602m

St.

249

29°38'2 W

74°37'4S

701-708 m

St.

250

29°39’9 W

74°35'1 S

799-810 m

St.

261

29°35'5 W

74°36'5 S

798-810 m

15*

St.

269

19°49'4 W

72°54'7 S

602-617 m

Ctenocidaris spinosa

St.

274

12°09'4 W

71°38'8S

196-212 m

St.

275

12°34'7 W

71°39'5 S

301-330m

St.

281

12°21 '1 W

71°39'0S

389-423 m

Ctenocidaris sp.

St.

217

46°58'1 W

60°37'6S

232-239 m

St.

258

29°36'6 W

74°40'2 S

484-509 m

Homalocidaris gigantea

St.

217

46°58'1 W

60°37'6 S

232-239 m

St.

235

27°34'7 W

75°09'1 S

404-407 m

St.

258

29°36'6 W

74°40'2S

484-509 m

St.

271

20°59'4 W

73°17'0S

352-399 m

St.

270

20°45'1 W

73°21'3 S

294-305 m

St.

275

12°34'7 W

71°39'5 S

301-330 m

St.

291

12°33'5 W

71°06'1 S

499-515 m

Homalocidaris cf. gigantea

St.

248

29°31'3W

74°39'9 S

593-602m

Notocidaris gaussensis

St.

252

29°41'9W

74°28'2S

1153-1223 m

Notocidaris mortenseni

St.

226

25°53'5 W

75°17'1 S

593-624m

St.

226

25°58'3 W

75°15'9S

569-574m

St.

248

29°31'3 W

74°39'9S

593-602 m

St.

249

29°42'5 W

74°36'2S

699-712m

St.

290

12°34'0 W

71°05'9S

522-531 m

St.

291

12°33'5 W

71°06'1 S

499-515 m

Echinidae

Sterechinus agassizi

St.

312

00°06'3 W

54°43'9 S

471-320 m

Sterechinus antarcticus

St.

217

46°58'1 W

60°37'6 S

232-239 m

St.

224

13°04'2 W

71 0 15'8 S

185-187 m

— 415 —

St. 226

25°58 , 3 W

75°15'9S

569-574m

St. 229

26°12'5 W

75°14'9S

500-509m

St. 229

26°16'7 W

75°15'7S

498 m

St. 230

26°59'4 W

75°14'2S

270-280 m

St. 230

26°38'9 W

75°14'5 S

275-279 m

St. 235

27°34'7 W

75°09'1 S

404-407 m

St. 241

27°59'5 W

75°07'1 S

457-462 m

St. 241

28°00'3 W

75°02'9 S

451-453 m

St. 245

29°41'6W

74°39'7 S

483-484 m

St. 249

29°42'5 W

74°36'2 S

699-712m

St. 249

29°38'2 W

74°37'4S

701-708 m

St. 250

29°39'9 W

74°35'1 S

799-810m

St. 250

29°35'6 W

74°36'3 S

794-805 m

St. 252

29°41'9W

74°28'2 S

1153-1223 m

St. 253

29°41'4W

74°09'5 S

1996-2012 m

St. 256

27°36'4 W

75°10'9S

382-399 m

1 *

St. 258

29°36'6 W

74°40'2 S

484-509 m

St. 259

29°16'8 W

74°40'2 S

587-611 m

St. 261

29°35'5 W

74°36'5 S

798-810 m

St. 269

19°49'4 W

72°54'7 S

602-617 m

St. 270

20°45'1 W

73°21'3 S

294-305 m

St. 272

21°33'6W

73°26'9S

406-409 m

St. 273

2r03'9W

73°34'8 S

193-197 m

261

St. 274

12°09'4 W

71°38'8 S

196-212 m

St. 275

12°34'7 W

71°39'5 S

301-330 m

St. 281

12°21'1 W

71°39'5S

402-450 m

St. 282

12°27'4 W

71 °31 '7 S

609-575 m

St. 284

13°14'0 W

71°12'0S

402-412 m

St. 289

13°27'9 W

71°12'0S

672-677m

St. 290

12°34'0 W

71°05'9S

522-531 m

St. 291

12°33'5 W

71W2S

499-515m

St. 293

12°53'8 W

71°06'2S

771-793m

Urechinidae

Plexechinus nordenskjoldi

St.

217

46°56'1 W

60°37'6S

232-239m

St.

252

29°41'9W

74°28'2S

1153-1223 m

St.

261

29°35'5 W

74°36'5 S

798-810 m

St.

289

13°27'9 W

71°12'0S

672-677m

St.

291

12°33'5 W

71°06'2S

499-515m

Plexechinus planus

St.

252

29°41'9W

74°28'2S

1153-1223 m

st:

295

13°48'1 W

71°08'8 S

2037-2025 m

Urechinus mortenseni

St.

249

29°38'2 W

74°37'4S

701-708 m

St.

252

29°41'9W

74°28'2 S

1153-1223 m

Urechinus wyvilli

St.

253

29°41'4 W

74°09'5S

1996-2012 m

St.

295

13°48'1 W

71°08'8 S

2037-2025 m

— 416 —

POURTALESIIDAE

Pourtalesia aff. hispida

St. 252 29°41'9 W 74“28'2S 1153-1223 m 7

SCHIZASTERIDAE

Abatus cavernosus

St. 217

46°56'1 W

60°37'6 S

232-239 m

Amphipneustes bifidus

St. 258

29°36'6 W

74°40'2 S

484-509 m

St. 272

21°33’6W

73°26'9S

406-409 m

St. 275

12°34'7 W

71°39'5S

301 -330 m

St. 281

12°21'1 W

71°39'5 S

402-450 m

St. 284

13°14'0 W

71°12'0S

402-412 m

St. 290

12°34'0 W

71°05'9 S

522-531m

Amphipneustes lorioli

St. 211

55°20'1 W

60°59'8 S

182-213 m

St. 217

46°56'1 W

60°37'6S

232-239 m

12 *

St. 235

27°33'2 W

75°08'9S

399-404 m

St. 235

27°34'7 W

75°09'1 S

404-407 m

St. 241

28W3 W

75°02'9 S

451-453 m

St. 250

29°39'9 W

74°35'1 S

799-810m

St. 253

29°41'4 W

74°09'5S

1996-2012 m

St. 256

27°36'4 W

75°10'9 S

382-399 m

St. 261

29°35'5 W

74°36'5 S

798-810 m

St. 273

21°03'9 W

73°34'8 S

193-197 m

Amphipneustes rostratus

St. 235

27°34'7 W

75°09'1 S

404-407 m

St. 248

29°31'3W

74°39'9 S

593-602 m

St. 249

29°42'5 W

74°36'2S

699-712m

St. 249

29°38'2 W

74°37'4S

701-708m

St. 250

29°39'9 W

74°35'1 S

799-810 m

St. 252

29°41'9W

74°28'2S

1153-1223 m

St. 261

29°35'5 W

74°36'5 S

798-810 m

St. 272

21°33'6 W

73°26'9S

406-409 m

St. 290

12°34'0 W

71°05'9 S

522-531m

Amphipneustes similis

St. 211

55°20'1 W

60°59'8 S

182-213 m

St. 217

46°56'1 W

60°37'6S

232-239 m

St. 235

27°34'7 W

75°09'1 S

404-407 m

St. 241

27°59'5 W

75°07'1 S

457-462 m

Brachysternaster ehesheri

St. 217

46°56'1 W

60°37'6S

232-239 m

2 *

St. 235

27°34'7 W

75°09'1 S

404-407 m

St. 241

28°00'3 W

75°02'9 S

451-453 m

St. 250

29°35'6 W

74°36'3 S

794-805 m

St. 252

29 0 41'9 W

74°28'2S

1153-1223 m

St. 256

27°36'4 W

75°10'9S

382-399 m

St. 261

29°35'5 W

74°36'5 S

798-810 m

— 417

Delopatagus brucei

St. 253

29°41'4W

74°09'5 S

1996-2012m

Parapneustes abatoides

St. 211

55°20'1 W

60°59'8 S

182-213 m

St. 217

46°56'1 W

60°37'6S

232-239m

St. 248

29°31'3 W

74°39'9 S

593-602m

St. 249

29°38'2 W

74°37'4S

701-708m

St. 250

29°39'9 W

74°35'1 S

799-810 m

St. 250

29°35'6 W

74°36'3 S

794-805 m '

St. 261

29°35'5 W

74°36'5 S

798-810 m

Taxonomic comments

The affinities and taxonomic position of 18 species or subspecies : Aporocidaris antarctica,

Ctenocidaris nutrix nutrix, C. nutrix longispina, C. perrieri, C. speciosa, C. spinosa,

Homalocidaris gigantea, Notocidaris mortenseni, N. gaussensis, Kamptosoma asterias, Sterechi-

nus diadema, Plexechinus planus, P. aff. cinctus, Pourtalesia aff. hispida, Amphipneustes

rostratus, Brachysternaster chesheri, Parapneustes abatoides and Delopatagus brucei are

discussed.

Aporocidaris antarctica Mortensen, 1909

Aporocidaris antarctica Mortensen, 1909 : 25, pi. 3 figs 5-7, pi. 5 figs 2, 9-11, pi. 7 figs 4-5, pi. 10

figs 6, 9, pi. 11 figs 10, pi. 13 figs 3, 6, pi. 14 figs 1, 16, 17, pi. 15 figs 8, 12-13, 16, 24-28,

pi. 16 fig. 15; Mortensen, 19286 : 116.

This species was known only from the 12 specimens collected by the ‘Deutsche Südpolar

Expedition' at 2725-3486m depth (Mortensen, 1909) and supposedly by some other material

from previous collections (Mortensen, 19286). The specimens from the MD03 expedition

extend the known geographical distribution of this species, for they were collected in the same

quadrant of the Antarctic Sea, but far to the north, close to the Antarctic convergence. Work

in progress (A.L.) on this species shows that its systematic status is precarious.

CTENOCIDARIS Mortensen, 1910

This genus comprises 7 species which appear closely related to each other. They differ

mainly in the shape and ornamentation of the oral primary spines, in the length and

ornamentation of the coronal primary spines, and, in some species, in the arrangement of the

apical plates (Mortensen, 19286). Differences and similarities between C. nutrix nutrix and C.

nutrix longispina, as well as between C. perrieri, C. speciosa and C. spinosa are discussed below.

418

Ctenocidaris nutrix nutrix (Wyville Thomson, 1876)

Cidaris nutrix Wyville Thomson, 1876 : 62.

Stereocidaris nutrix; Mortensen, 1903 : 25, 29, 173, pi. 10 figs 3-4, 12, 14, 24.

Eurocidaris nutrix; Mortensen, 1909 : 30, pi. 3 fig. 9, pi. 4 figs 5-6, pi. 6 figs 2, 4-9, 11-

12, pi. 10 figs 7, 11, pi. 11 fig. 12, pi. 13 fig. 7, pi. 15 figs 17, 20-23.

Ctenocidaris (Eurocidaris) nutrix; Mortensen, 19286 : 128.

Ctenocidaris nutrix longispina (Mortensen, 1928a)

(PI. I, 1-3)

Eurocidaris nutrix var. longispina Mortensen, 1928a : 67.

Ctenocidaris ( Eurocidaris) nutrix var. longispina; Mortensen, 19286 : 129, pi. 57 fig. 8.

The original diagnostic character (length of the primary coronal spines) for these two

subspecies is unreliable. Later, Mortensen (19286) found differences in the position of the

ocular plates (all insert in C. nutrix longispina, while they are usually exsert in C. nutrix nutrix).

Our identification of the specimens from Epos III is based on this latter characteristic (pi. I, 2).

However, the distinction between the two subspecies is weakly grounded (as already noticed by

Clark, 1925), and it may be necessary to reconsider their status.

Ctenocidaris perrieri Koehler, 1912a

(PI. II, 1-3)

Ctenocidaris perrieri Koehler, 1912a : 161 ; Kcehler, 19126 : 150, pi. 12 figs 4-8, pi. 13 figs 2-8,

pi. 14 figs 9-14, pi. 15 figs 1-10; Mortensen, 19286 : 123, pi. 69 fig. 23

Ctenocidaris speciosa Mortensen, 1910

(PI. Ill, 1-3)

Ctenocidaris speciosa Mortensen, 1910 : 4, pis 1-2, pi. 3 figs 1-3, pi. 8; Mortensen, 19286 : 122.

Ctenocidaris spinosa (Koehler, 1926)

(PI. IV, 1-2)

Notocidaris spinosa Koehler, 1926 : 14, pi. 97 figs 1-6, pi. 98 figs 1-7, pi. 99 figs 1-3, pi. 112 fig. 7,

pi. 114 fig. 7, pi. 119 fig. 6.

Ctenocidaris spinosa; Mortensen, 19286 : 124, pi. 12 fig. 13, pi. 77 figs 10-12.

C. spinosa was previously known only from the ‘Aurora’ specimens. Mortensen (19286)

stated that C. perrieri is probably the nearest related to C. speciosa and that both are very close

to C. spinosa. We distinguish these three species on the basis of size and spinulation of the

coronal primary spines, the shape and ornamentation of the oral primary spines, the

— 419

tuberculation close to the median interradial suture, and the color of the test. C. spinosa

possesses densely and strongly thorny primary coronal spines (pi. IV, 1); denticules are sharp,

arranged in ca. 8 longitudinal series that may fuse into ridges. Oral primaries are spear-shaped

and bear sharp, lined spinules, these spinules sometimes fused into two lateral wings (pi. IV,

2). A supplementary character, not mentioned by Mortensen (19286), is noted : there is a

conspicuous naked area on both sides of the interradial suture. The color is typically brownish

purple. C. perrieri differs from C. spinosa in having slender coronal primaries which show a

less regular arrangement of their spinules (lack of ridges), blunter spinules on the oral

primaries (pi. II, 3), tuberculation which reaches the interradial suture (lack of naked areas),

and a yellowish color. C. speciosa has finely serrated coronal primaries (pi. Ill, 1-2), flattened

oral primaries bearing blunt, coarse spinules (pi. Ill, 3). The median interradial area and the

color of the specimen^ are similar to those of C. perrieri.

Homalocidaris gigantea (Clark, 1925)

(PI. IV, 3-4)

Austrocidaris gigantea Clark, 1925 : 28, pi. 3 figs 1-2.

Homalocidaris gigantea; Mortensen, 19286 : 137, pi. 11 fig. 6, pi. 77 fig. 14, pi. 83 fig. 23; Mor¬

tensen, 1950a : 297, pi. 7 figs 4-6.

This species was only known by two specimens sampled by the ‘Discovery’ near Victoria

Land in the Ross Sea at 180 m depth (Clark, 1925) and by two specimens sampled by the

BANZAR expedition in the Bellingshausen Sea off Palmer Archipelago (Mortensen, 1950a).

The third record corresponds to the 15 specimens collected during the Epos III expedition in

the Weddell Sea. These specimens fit closely the description given by Clark (1925) and

completed by Mortensen (19286). Their simultaneous occurrence in two distinct quadrants

indicate that the distribution of the species is probably circum-Antarctic.

NOTOCIDARIS Mortensen, 1909

Notocidaris mortenseni (Koehler, 1900)

Goniocidaris mortenseni Koehler, 1900 : 816; Kcehler, 1901 : 5, pi. 1 fig. 1 pi. 2, fig. 11, pi. 3 fig. 17,

pi. 4 fig. 29, pi. 5 fig. 30.

Stereocidaris mortenseni; Mortensen, 1903 : 27, 29, pi. 8 fig. 34.

Notocidaris mortensi; Mortensen, 1909 : 21, pi. 3 figs 1, 8, 10, pi. 14 figs 3, 6; Mortensen, 19286 :

131, pi. 11 figs 13-15, pi. 68 fig. 15.

Notocidaris gaussensis Mortensen, 1909

(PI. V, 1-2)

Notocidaris gaussensis Mortensen, 1909 : 18, pi. 1, pi. 2 figs 1-2, pi. 5 figs 13-16, 19-21, pi. 7 fig. 2,

pi. 10 figs 5, 8, pi. 11 fig. 3, pi. 13 fig. 1, pi. 14 figs 2, 4, 10, 15, pi. 15 fig. 10, pi. 18 figs 9-11,

14, 17-18; Mortensen, 19286 : 134.

— 420 —

The features of the upper primary spines given by Mortensen (1928 b) to separate TV.

mortenseni from TV. gaussensis are confusing because the ornamentation of these spines varies.

These species differ markedly in their upper and oral primaries. TV. gaussensis has wingless

upper primaries that are usually smooth all along the shaft and sometimes distally flattened

(pi. V, 1). Oral primaries are spear-shaped, slightly curved, and smooth (pi. V, 2). TV.

mortenseni has upper primaries bearing large, coarse spinules that may fuse together into wing¬

like extensions. Oral primaries are keeled (two opposite keels), triangularly spear-shaped,

straight, and serrated at their basis. Some variations exist; one TV. mortenseni (among the

8 specimens of station 248) has simple upper primaries and gently curved oral primaries,

widened centrally, and more or less diamond shaped.

Kamptosoma asterias (A. Agassiz, 1881)

Phormosoma asterias A. Agassiz, 1881 : 104, pi. 12a figs 7-9.

Kamptosoma asterias-, Mortensen, 1903 : 60, 177, pi. 11 fig. 18, pi. 12 figs 12, 32, pi. 13 figs 9, 15,

21, pi. 14 fig. 29; Mortensen, 1935; 157, pi. 3 figs 5-8, pi. 76 figs 17-19.

Eight specimens were collected during the MD03 expedition. They constitute the second

record of this deep-sea species, and extend its geographical distribution to the South Indian

Ocean. The ‘ Challenger’ material originated from the Central Pacific Ocean, and off the coast

of Chile.

Sterechinus diadema (Studer, 1876)

Echinus diadema Studer, 1876 : 456.

Sterechinus margaritaceus ; Mortensen, 1903 : 101, 105, 177, pi. 19 figs 3, 20, 33.

Sterechinus diadema', Dôderlein, 1903-1906 : 219, 225, pi. 27 fig. 5, pi. 35 fig. 1, pi. 47 figs 8, 10c;

Mortensen, 1943 : 102, pi. 13 figs 3-4, pi. 19 figs 1-5, pi. 20 figs 4-5, pi. 56 figs 1-3.

S. diadema was dredged during the MD03, MD04, MD08 and ‘Japonaise’ expeditions

around Marion, Crozet, Kerguelen and Heard islands. The specimens were identified on the

basis of the diagnostic features given by Mortensen (1943). Mots of these features, observed

in our specimens, vary in the direction of S. neumayeri. The general shape of the test varies

from subconical to regularly hemispherical ; the color of the cleaned test varies from whitish to

brownish ; the tube feet spicules are numerous or scarse ; the outer corners of the valves of the

globiferous pedicellariae may be produced. The question, whether S. neumayeri is really a

distinct species from S. diadema, has been debated by Clark (1925) and Mortensen (1943).

Clark (1925) considered them to be a single species, while Mortensen (1943) concluded that

they have to be maintained as distinct, even thought he recognized that “ none of these

characters are absolutely constant” (p. 108). The range of variation shown in the present

collection leads us to suspect that S. diadema and S. neumayeri are synonymous. A decision

should be delayed until complementary non-morphological (i.e. molecular) arguments could

be added to the discussion.

— 421 —

Plexechinus planus (Mironov, 1978)

Urechinus planus Mironov, 1978 : 216, pi. 1 figs 7, 8, pi. 2 figs 1, 2, 5, 6, pi. 3 figs 2, 4, 9.

The specimens from the Epos III collection are similar to those collected off South

Tasmania during the 16th cruise of the R/V “D.M. Mendeleyev” (Mironov, 1978). However,

considering the characteristics of the Epos III specimens and Mironov’s original description,

it is preferable to refer the species to the genus Plexechinus instead of Urechinus (fig. 2). The

genera of Urechinidae are primarily based on the simultaneous occurrence of a subanal

fasciole and an anal snout, and on the supra- or inframarginal position of the periproct. In

fact, this distinction is rather confusing. The characters used for the distinction participate to

progressive ontogenetic changes and are part of a morphological continuum between small

species (i.e. Plexechinus spp.) presenting an anal snout, a conspicuous fasciole and a

supramarginal periproct, and larger species (Urechinus spp.) lacking anal snout and fasciole,

and presenting an inframarginal periproct. The limits fixed for each genus are arbitrary and

unreliable and should be reconsidered, taking into account features other than those directly

involved in ontogeny. The architecture of the plastronal area provides a more accurate generic

distinction. Adults of Plexechinus generally display a discontinuous interambulacrum 5 that is

interrupted by a pair of ambulacral plates joining on the midline, and the labrum is elongated ;

Fig. 2. — Plexechinus planus

— 422 -

occasionally interambulacrum 5 may be continuous, but with a narrow boundary between

labrum and sternum (fig. 2b). Urechinus exhibits a classical plate pattern with a fully

continuous interambulacrum 5. U. aoteanus McKnight (1976), reported as the only Urechinus

species to present a discontinuous pattern, should be referred to Plexechinus. The tubercula-

tion adds further arguments to this distinction : miliary tubercles form a regular dense coating,

very apparent on the apical side in Plexechinus, while they are more scarcely distributed in

Urechinus. Nevertheless even using these characters, the generic assignment remains ambi¬

guous for some species, e.g. the brooding form P. nordenskjoldi (David & Mooi, 1990).

Further large scale studies involving both ontogenetic and cladistic analyses are needed to

clarify the relationships within the family.

Plexechinus aff. cinctus A. Agassiz, 1898

Plexechinus cinctus A. Agassiz, 1898 : 78, pi. 8 figs 3, 4; A. Agassiz, 1904 : 150, pi. 55 figs 3-5,

pi. 58 figs 1-4, pi. 59, pi. 60 figs 1-3; Mortensen, 19506 : 119.

One broken specimen of MD03 from the Kerguelen region shows very puzzling

characteristics and cannot be related with certainty to a known species. It is about 40 mm in

length and its color is white purplish. Its general shape is elongated, with a triangularly

grooved frontal ambulacrum resembling to some extent that of some extinct Holaster. A

conspicuous subanal fasciole surrounds a smooth rostrum. The apical system is widely disjunct

with separated bivium and trivium, and two gonopores open into a single genital plate. The

interambulacrum 5 is interrupted by one pair of ambulacral plates between the labrum and the

sternum. The miliary tuberculation forms a dense coating on the apical side. All those

characters, excepts the sharp edged ambulacrum III. fit rather well the description of P.

cinctus. This species is known only by two specimens from the Gulf of California at 1235 m

depth, but it is the only one to which the MD03 specimen may be related although it has been

found at a much shallower depth (585 m).

Pourtalesia aff. hispida A. Agassiz, 1879

Pourtalesia hispida A. Agassiz, 1879 : 204, pi. 205 figs 1-8, pi. 121 fig. 3; A. Agassiz, 1881 : 136,

pi. 22 figs 6-19, pi. 39 figs 34, 36, pi. 41 figs 47, 48. Mortensen, 19506 : 149.

Specimens from Epos III resemble the two species of Pourtalesia which exhibit a short,

but not elevated subanal rostrum (i.e. P. aurorae and P. hispida). Although they do not really

fit either of these two species descriptions, they seem closer to P. hispida than to P. aurorae.

The features shared with P. hispida are the vaulted lateral profile, the elongated general shape,

and the serrated primary spines. On the other hand, the primary spines are not lined in regular

horizontal rows and the ambital outline does not show parallel margins (they are curved as in

P. aurorae). The position of the apex differs from the two above species ; it is less anterior in

the Epos III specimens. Owing to the relatively limited knowledge of the Antarctic species of

Pourtalesia it is preferable to avoid describing a new species until more material becomes

available (P. aurorae is based on 8 specimens described by Kcehler, 1926, and some fragments

noted by Mironov, 1978; P. hispida is known from two type specimens, since destroyed.

— 423

described by A. Agassiz, 1879, and from the specimen described by Kcehler, 1929). We refer

the Epos III specimens to P. aff. hispida. The geographic distribution is rather different, the

previously known specimens of P. hispida being reported from the South Indian Ocean (South

Heard island).

Amphipneustes rostratus (Kcehler, 1926)

Antipneustes rostratus Koehler. 1926 : 70, pi. 114 figs 1-6, pi. 115 figs 1, 3, 4, 6, pi. 116 figs 1-6,

pi. 117 figs 1, 2, 6, 9, pi. 124 fig. 1.

Amphipneustes rostratus ; Mortensen, 1951 : 268.

This species shows a wide range of individual variation and it was until now known only

from a few specimens. A. rostratus is easily recognizable by its very large globiferous

pedicellariae whose location remains detectable on naked tests by black spots. The posterior

end of the test presents some variation as it may be vertically truncated with a marginal

periproct, or rounded with an almost inframarginal periproct. The posterior interambulacrum

may be depressed above the periproct. The ambital outline is usually more or less heart-

shaped, but a few specimens have an almost oval ambitus. The sternum varies in width : it is

wide and triangular in rounded specimens and narrow with parallel borders in more elongate

specimens. The apical surface is covered by small tubercles densely distributed. Although

Amphipneustes is characterized by the lack of fascioles, some of the Epos III A. rostratus may

show a marginal fasciole, and one specimen has a short portion of a peripetalous fasciole.

Brachysternaster chesheri Larrain, 1985

Brachysternaster chesheri Larrain,, 1985 : 121, figs 1-3.

The numerous specimens of Brachysternaster collected during Epos III expedition allow

us to add some comments about the range of variation of this species. All the Epos III

specimens fit closely to Larrain’s description of the type and the two paratypes in the general

shape of the test and the plate architecture. However, two “forms” can be distinguished :

(1) large (ca. 75 mm in length) purplish specimens with scarce, evenly distributed primary

tubercles; (2) smaller (ca. 55mm in length) yellowish specimens with a more dense canopy of

primaries. Both forms show on the apical side numerous scars which result from the loss of

primary tubercles (similar to those observed in other irregular echinoids, David &

Néraudeau, 1989). Statistical comparisons of some shape parameters show no morphological

differences between the two forms.

Parapneustes abatoides (Clark, 1925)

(PI. V, 3-4)

Pericosmus abatoides H„ L. Clark, 1925 : 199, pi. 11 figs 4-6.

Tripylus ( Parapneustes ) abatoides ; Mortensen, 1951 : 279.

Kcehler (19126) created the genus Parapneustes for two new species, P. cordatus and P.

reductus, without proposing a type species. On the basis of the two specimens available (i.e. the

— 424

two holotypes) Kœhler noted that P. cordatus possesses only a peripetalous fasciole, while P.

reductus possesses both a peripetalous and a marginal fasciole. Clark (1925) described a new

species, Pericosmus abatoides, which also possesses a peripetalous and a marginal fasciole.

Later, he referred the species to the Schizasteridae, stating that “ it is probably related to

Abatus and will ultimately have to be made the type of a new genus” (1932 : 218). Finally,

Mortensen (1951) studied specimens of Parapneustes cordatus collected by the “Discovery”,

and reported the occurrence of a latero-subanal fasciole (not observed by Kœhler on the type

specimen). He then referred cordatus to Tripylus (Parapneustes ), restricting Parapneustes as a

subgenus. He also placed Kœhler’s and Clark’s species ( reductus and abatoides, respectively)

in Tripylus (Parapneustes ). He based his decision on a reinterpretation of the fascioles,

Fig. 3. — Parapneustes abatoides.

considering that both Kœhler and Clark’s “marginal fasciole” was in fact the latero-

subanal fasciole. Mortensen had drastically revised Kœhler and Clark’s descriptions

without having any specimen in hand. The Epos III specimens perfectly fit the species P.

abatoides (fig. 3). They corroborate Clark’s description and cost doubt on Mortensen’s

interpretations. They possess a complete marginal fasciole and a peripetalous fasciole which

— 425

never' crosses the anterior ambulacrum (fig. 3a). In some specimens, the peripetalous fasciole

turns backwards for a more or less short distance, thus appearing double on the anterior

interambulacra (a characteristic already quoted by Clark). Similarly, the illustrations of the

species reductus given by Koehler clearly show the presence of a marginal fasciole. Owing to

these observations it is preferable to refer reductus and abatoides to Parapneustes and to retain

cordatus in Tripylus. The proposed taxonomic position for P. abatoides is reinforced by the

length of the latero-anterior petals, which reach the peripetalous fasciole. In complete revision

of the brooding schizasterids, we would suggest that : (1) the genus Parapneustes is valid, and

includes P. abatoides and P. reductus ; (2) the genus Tripylus includes T. cordatus, T. excavatus

and T. beatriceae; (3) the genus Tripylus could be close to Abatus , because of both possess a

latero-subanal fasciole.

Delopatagus aff. brucei Kœhler, 1907

Delopatagus brucei Kœhler, 1907 : 147; Kœhler, 1908 : 622, pi. 15 figs 130-135; Mortensen, 19506 :

252.

The morphological characters of the two broken specimens collected during the Epos III

Expedition are those given by Kœhler in 1908. The Epos III specimens show a minor

difference — their latero-posterior petals are not shorter than the anterior ones. This is why we

identify them as D. aff. brucei. Recent RNA-sequencing studies reveal that the Epos III

specimens of Delopatagus are very close to Amphipneustes (Féral & Derelle, 1991). These data

must be taken into account in reconsidering the taxonomic position of the genus Delopatagus

as far as the Asterostomatidae constitutes an heterogenous polyphyletic group (Fisher, 1966).

We suggest that Delopatagus belongs to the Schizasteridae, close to Amphipneustes. Like

Amphipneustes, Delopatagus has no fascioles. Moreover, additional specimens held at the

Smithsonian Institution (USNM El 1063, El 1274, El 1275, El 1286) have depressed petals that

house juveniles. This indicates that D. brucei is a brooding species. This is strong evidence in

supporting the idea that Delopatagus belongs in the Schizasteridae, the only brooding family in

the spatangoids.

DISCUSSION

1. Geographical distribution

Two circumpolar regions, the Antarctic and the Subantarctic Regions are involved here.

The Antarctic Region corresponds to an area extending from the shore of the Antarctic

Continent to the Antarctic Convergence (fig. 4) ; it includes a large series of islands, namely,

the South Shetlands, South Orkneys, the South Sandwich, South Georgia and Bouvet islands.

As defined by Pawson (1969), the Subantarctic Region covers a vast oceanic area south of the

Subtropical Convergence (except that the limits of this region on the two sides of South

America are not yet defined), and the shallow waters of the tip of South America (fig. 4) ; it

includes Kerguelen, Heard and Macquarie Islands but not the southern of New Zealand

although this lies within the limits of the Subtropical Convergence. Both regions are

426 —

3 0' O’ 30’

— 427 —

subdivided into four geographical quadrants : the Weddell, the Enderby, the Victoria and the

Ross quadrants that respectively correspond to an American, an African, an Australian and a

Pacific zone; these quadrants are identified for convenience; they have no biological

significance. The biogeographic divisions used further in this discusion are those proposed by

Pawson (1969) : the Magellanic Subregion or Province, the Tristan da Cunha District and the

Kerguelen Subregion or Province, for the Subantarctic region; the Continental or High

Antarctic Subregion or Province, the extension of Continental Subregion of Province, the

Scotia Subregion and the South Georgia District, for the Antarctic Region.

As already mentioned by Pawson (1969) and by Dell (1972), over 50 families of

echinoids are known but only six of them, namely, the Cidaridae, the Echinidae, the

Arbaciidae, the Urechinidae, the Pourtalesiidae, and the Schizasteridae, occur in the Antarctic-

Subantarctic Regions. A seventh family, the Echinothuriidae, can be added to this list, as

specimens of Kamptosoma asterias were collected south of Heard Island during the MD03

Expedition. Very characteristic are the absence of the vast assemblage of regular non-cidaroid

echinoids (apart from two genera, Sterechinus and Kamptosoma), and the diversity of two

families, the Schizasteridae and the Cidaridae (within which all the Antarctic-Subantarctic

species belong to one subfamily, the Ctenocidarinae) (Pawson, 1969). The geographic

distributions of the species collected are summarized in Table 6. There are several new range

extensions. Wide latitudinal extensions, i.e., from one zone to another, are observed for five

species : Kamptosoma asterias which extends from the Temperate to the Subantarctic Zone,

Ctenocidaris nutrix longispina, Urechinus wyvilli, Plexechinus planus, and Brisaster kerguelensis

which extend from the Subantarctic to the Antarctic Zone. Longitudinal extensions are

observed within the Antarctic Zone, the Subantarctic Zone or both simultaneously. Within the

Antarctic Zone, four species previously unreported in the Weddell Quadrant were collected in

the Weddell Sea : Amphipneustes rostratus (known from the Victoria Quadrant), Homalocida-

ris gigantea (known from the Ross and the Victoria Quadrants), Pourtalesia hispida (known

from the Victoria and Enderby Quadrants), Amphipneustes bifidus (known from the Enderby

Quadrant), and Parapneustes abatoides (known from the Ross Quadrant). Nine other species

('Ctenocidaris speciosa, Notocidaris gaussensis, Notocidaris mortenseni, Sterechinus antarcticus,

Plexechinus nordenskjoldi, Abatus cavernosus, Amphipneustes lorioli, Amphipneustes similis and

Brachysternaster chesheri ), already reported in the Weddell Quadrant in the Bellingshausen

Sea or along the Antarctic peninsula are now known to occur in the east part of the Weddell

Sea. Within the Subantarctic Zone, two species extend longitudinally : in the Enderby

Quadrant, Brisaster kerguelensis, known from Kerguelen and Bouvet Islands, reaches the

Crozet and Heard Islands ; Tripylaster philippi, known in the Weddell Quadrant, extends to the

Enderby Quadrant (Marion and Prince Edward Islands). One species, Sterechinus neumayeri,

known in both Antarctic and Subantarctic Zones from three Quadrants extends in both Zones

simultaneously to the fourth Quadrant (Enderby Quadrant).

— 428 -

Table 6. — Geographical distribution of the collected species (expanded areas, corresponding to this

paper, are in bold-fact types).

Species

Antarctic (AZ),

Subantarctic (SAZ)

or Temperate (TZ)

zones

Localities

(W.Q. = Weddel quadrant.

E.Q. = Enderby quadrant

V.Q. = Victoria quadrant,

R.Q. = Ross quadrant)

Data sources

Aporocidaris an-

tarctica

SAZ + AZ

E.Q. + V.Q. (off Elizabeth to

Queen Mary Lands, Kergue¬

len Isl.)

Bell 1908, 1917; Kœhler

1912a, 6; Mortensen 19286;

Pawson 1969

Clenocidaris nutrix

SAZ + AZ

E.Q. (off Antarctic coast, Ker¬

guelen, Crozet, Heard Isl.)

Agassiz 1881 ; Dôderlein 1903-

06; Guille 19776; Kœhler,

1912 a, b. 1917; Mortensen

1903, 1909, 19286; Pawson,

1969; Studer 1876, 1880;

Wyv. Thompson 1876, 1877

Ctenocidaris nutrix

longispina

SAZ

E.Q. (Heard Isl.) + W.Q.

(Weddel Sea)

Mortensen 1928a, 6

Ctenocidaris per-

rieri

W.Q. (South Shetlands Isl., Pal¬

mer Arch..Bellingshausen Sea,

Weddell Sea) + V.Q. (Balle-

ny Isl.) + R.Q. (Ross Sea)

Bell 1908, 1917; Kœhler

1912a, 6; Mortensen 1925,

19286; Pawson, 1969; Fell

1976

Ctenocidaris spe-

ciosa

SAZ + AZ

V.Q. (Coulman, Balleny Isl.)

+ W.Q. (off Graham Land,

Palmer Arch., South Georgia

South Orkneys, South Shet¬

lands Isl., Shag Rocks, off Tier-

ra del Fuego, Weddell Sea)

Bernasconi 1953; Kœhler

1926; Mortensen 1910, 1928a,

6, 1936; Pawson 1969; Fell

1976

Ctenocidaris spino-

V.Q. (off Queen Mary Land)

+ W.Q. (Weddell Sea)

Kœhler 1926; Mortensen

19286; Pawson 1969; Fell

1976

Homalocidaris gi-

gantea

R.Q. (Ross Sea) + V.Q. (off

Victoria Land) + W.Q. (Wed¬

del Sea)

Clark 1925; Me Knight 1976;

Mortensen 19286, 1950a; Paw-

son 1969

Notocidaris gaus-

sensis

R.Q. + W.Q. (South Shet¬

lands Isl., Bellingshausen Sea,

Weddell Sea)

Kœhler 19126; Mortensen

1909, 19286, 1950a; Pawson

1969; Fell 1976

Notocidaris mor-

tenseni

E.Q. (off Kemp Land to Wil-

hem II Land) + W.Q. (South

Shetlands Isl., Weddell Sea)

Bernasconi 1953; Dôderlein

1903-06; Kœhler 1900, 1901 ;

Mortensen 1909, 19286; Paw¬

son 1969; Fell 1976

Kamptosoma aste-

rias

TZ + AZ

off coast of Chile (33°31'S) +

E.Q. (South Heard Isl.)

A. Agassiz 1881, 1904; Mor¬

tensen 1903, 1935

Sterechinus agas-

sizi

SAZ + AZ

W.Q. (South Georgia, Falk-

lands Isl.), South Atlantic (Ame¬

rican coast up to 46°14'S)

Agassiz 1872-74; Bernasconi

1953; Kœhler 19126, Meiss¬

ner 1900; Mortensen 1909,

1943; Pawson 1969

— 429 -

Sterechinus antarc-

ticus

W.Q. (South Georgia, South

Shetlands Isl., Palmer Arch.,

off Graham Land, Weddell Sea)

+ V.Q. (Balleny Isl.) + E.Q.

(Kemp Land to Mac-Robert-

son Land)

Bernasconi 1953; Kœhler

1901, 19126, 1926; Me Knight

1976; Mortensen 1903, 1909,

1936, 1943, 1950a; Pawson

1969

Sterechinus neuma-

yeri

SAZ + AZ

V.Q. (off Terre Adélie, Balle¬

ny Isl.) + W.Q. (Palmer Arch.,

South Orkneys, South Shet¬

lands, South Georgia, South

Patagonia Isl.) + R.Q. (Ross

Sea) + E.Q. (Prince Edward,

Marion, Crozet, Kerguelen Isl.)

Arnaud 1965 ; Bernasconi

1953; Dôderlein 1903-06;

Grieg 1929a, 6; Kœhler 1908,

1912b, 1926; Me Knight 1976;

Mortensen 1903, 1909, 1910,

1925, 1936, 1943, 1950a; Paw-

son 1969

Plexechinus planus

SAZ + AZ

V. Q. (44°06'S-145°56'E) +

W. Q. (Weddell Sea)

Mironov 1978

Plexechinus nor-

denskjoldi

E.Q. (off Enderby to Mac-

Robertson Lands) W.Q. (South

Georgia Isl., Antarctic, Wed¬

dell Sea)

Bernasconi 1953; Kœhler

19126; Mortensen 1905, 1909,

1910, 1936, 1950a

Urechinus wyvilli

SAZ + AZ

Subantarctic Sea (E.Q., V.Q.,

R.Q., W.Q.) + off Pacific

coast of Chile (up to 33° S) +

W.Q. (Weddell Sea)

A. Agassiz 1879, 1881 ; Kœh¬

ler 1908; Mortensen 1907,

1909, 19506; USNM collec¬

tions

Urechinus morten-

seni

W.Q. (off Graham Land)

David & Mooi 1990

Pourtalesia hispida

SAZ + AZ

E.Q. (extreme South of Indian

ocean) + V.Q. (off Queen Mary

Land) + W.Q. (Weddell Sea)

A. Agassiz 1881; Kœhler

19126, 1926; Mortensen 1907,

1909, 19506

Abatus cavernosus

SAZ + AZ

W.Q. (South America 36° S to

South Georgia, Palmer Arch.,

Weddell Sea) + V.Q. Terre

Adélie) + E.Q. (Kerguelen Isl.,

Heard Isl.)

Agassiz 1881 ; Bernasconi

1953; Dôderlein 1903-06;

Grieg 1929a, 6, Kœhler 1908,

1912b, 1926; Meissner 1900;

Mortensen 1909, 1910, 1936,

1950a, 1951; Pawson 1969;

Philippi 1845; Studer 1876,

1880

Abatus cordatus

SAZ

E.Q. (Kerguelen Isl.)

A. Agassiz 1881; Cherbon-

nier & Guille 1975; Dôder-

lein 1903-06; Guille 19776;

Kœhler 19126, 1917; Mor¬

tensen 1909, 1936, 1950a, 1951;

Pawson 1969; Smith 1879;

Studer 1876, 1880; Verrill

1876

Amphipneustes bi-

fidus

E.Q. (Enderby Land, Kemp

Land) + W.Q. (Weddell Sea)

Mortensen 1950a; Pawson

1969

Amphipneustes lo-

rioli

W.Q. (Palmer Arch., Belling¬

shausen Sea, Weddell Sea) +

V.Q. (between Queen Mary and

Wilkes Lands)

Bernasconi 1953; Kœhler

1900, 1901, 1912a, 6; Mor¬

tensen 1909, 1910, 1936, 1950a,

1951 ; Pawson 1969

— 430

Amphipneustes ros-

tratus

V.Q. (off Queen Mary Land to

Terre Adélie) + W.Q. (Wed¬

dell Sea)

Mortensen 1951; Pawson

1969

Amphipneustes si¬

milis

W.Q. (Palmer Arch., Weddell

Sea)

Bernasconi 1953; Mortensen

1936, 1951 ; Pawson 1969

Brachysternaster

chesheri

W.Q. (South Shetlands Isl.,

Weddell Sea)

Larrain 1985

Brisaster kergue-

lensis

SAZ + AZ

E.Q. (Kerguelen, Bouvet, Cro-

zet, Heard Isl.)

Dôderlein 1903-06; Morten¬

sen 1950a, 1951 ; Pawson 1969

Delopatagus brucei

W.Q. (South Georgia Isl., Wed¬

dell Sea)

Kcehler 1907, 1908, 19126;

Mortensen 1909, 19506

Parapneustes

abatoides

R.Q. (Ross Sea) + W.Q. (Wed¬

dell Sea)

Clark 1925; Mortensen 1951

Tripylaster philippi

SAZ + AZ

South America 35°S (Rio de

la Plata) to the Fuegian coast

+ W.Q. (South Georgia Isl.)

+ E.Q. (Prince Edward, Ma¬

rion Isl.)

Bernasconi 1953; Dôderlein

1903-06; Kcehler 19126; Meiss¬

ner 1900; Mortensen 1907,

1909, 1910, 1936, 1951. 1952;

Pawson 1969; Studer 1880

Three major patterns of distribution can now be identified among the echinoid genera :

1 — A circumpolar distribution in the Antarctic Zone only for six genera ( Homalocida-

ris, Notocidaris, Amphipneustes, Brachysternaster, Parapneustes, Delopatagus).

2 — A Circumpolar distribution in the Antarctic Zone, but with representatives in the

Magellanic and in the Kerguelen Provinces ( Ctenocidaris, Sterechinus), or with representatives

in the above mentioned Provinces and in the southern coastal waters of America for two other

genera ( Abatus which occurs up to 36° S off Argentina, and Tripylaster which occurs up to

4T50S off Chile and up to 35°S off Argentina).

3 — A circumpolar distribution in the Antarctic and Subantarctic Zones with represen¬

tatives in more northern areas : five genera ( Aporocidaris, Brisaster, Pourtalesia, Plexechinus,

Urechinus. These four last genera are deep-sea forms).

A deep-sea occurrence in the Subantarctic Zone is observed for Kamptosoma , a genus

already known from more northern areas.

According to Pawson (1969), fifteen genera ( Ctenocidaris, Rhynchocidaris, Homalocidaris,

Aporocidaris, Notocidaris, Sterechinus, Abatus, Amphipneustes, Brisaster, Tripylus, Tripylaster,

Delopatagus, Urechinus, Pourtalesia and Plexechinus) have been collected in the Antarctic

Zone. The total is now seventeen genera, with Brachysternaster described in 1985 by Larrain

and with Parapneustes revalidated in the present work. Two of the genera mentioned by

Pawson (1969), i.e. Rhynchocidaris and Tripylus, were not collected during the expeditions

reported here. Of the seventeen genera now known to occur in the Antarctic Zone, seven (see

pattern 1 + Rhynchocidaris) are restricted to the Antarctic Zone, five (see pattern 2 +

Tripylus) are restricted to the Antarctic-Subantarctic Zones and five occur elsewhere in the

world. The proportion of endemic genera in the Antarctic Zone calculated from our data is

higher than that mentioned by Dell (1972) (41 % versus 25%).

431

Fig. 5. — Bathymetrical distribution of the collected species (regular echinoids).

S. neumayeri

— 432 —

Fig. 6. — Bathymetrical distribution of the collected species (irregular echinoids).

433

2. Bathymetrical distribution

The continental shelf around Antarctica is narrow, except in the two embayments of the

Ross Sea and the Weddell Sea (Dell, 1972). Its outer limit generally lies between 400 and

600 m deep, but it reaches 800 m in the Ross Sea. The continental slope ends at depths of

3000 m. From there three main basins are arranged around the continent : an Atlantic-Indian-

Antarctic basin, an Eastern Indian-Antarctic basin and a Pacific-Antarctic basin. The northern

limits of each basin correspond to major ridges (crests located at depths less than 3000 m)

arranged in a more or less circumpolar fashion (Dell, 1972). Figures 5 and 6 summarize the

bathymetrical distribution of the species collected and displays a comparison between the

previously known bathymetric distributions and the distributions recorded in the present

work. We can expand downward the bathymetric range of several species. Two species

(Ctenocidaris nutrix longispina, and Amphipneustes bifidus) reach the outer edge of the

continental shelf in the Weddell Sea. Two other species reach the epibathyal zone ( Ctenocidaris

nutrix nutrix in the Kerguelen area, and Parapneustes abatoides in the Weddell Sea). The range

of five species is expanded from the continental shell to the bathyal zone : Notocidaris

gaussensis, Plexechinus nordenskjoldi, Amphipneustes rostratus, and Brachysternaster chesheri

in the Weddell Sea; Brisaster kerguelensis from the MD expeditions. One species, Amphipneus¬

tes lorioli, previously known to occur down to 600 m, reaches more than 2000 m in the Weddell

Sea.

Acknowledgements

Data presented here were collected during the European Polastern Study (Epos III) sponsored by the

European Science Foundation and the Alfred Wegener Institute for Polar and Marine Research. The

material was sorted by the Centre national d'Océanographie Biologique (CENTOB, IFREMER, Brest)

and W. Arntz chief of the Epos III cruise. We thank D. L. Pawson for his generous help in the

correction of the manuscript, J. H array for photographic assistance, and M. Klinkert for technical

support.

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437 -

Plate I.

Ctenocidaris nutrix longispina : apical view (1), oral view (2), lateral view (3).

Plate II. — Ctenocidaris perrieri : apical view (I), oral view (2), peri-oral area (3).

1cm

Plate III. — Ctenocidaris speciosa : apical view (1), oral view (2), peri-oral area (3).

c m

Plate IV. — Ctenocidaris spinosa ; oral view (1), peri

oral view (4)).

i-oral area (2). Homalocidaris giganlea : apical view (3),

apical view (3).

Notocidaris gaussensis : apical view (1), peri-oral area (:

Bull. Mus. natl. Hist, nat., Paris, 4‘ sér., 14, 1992,

section A, n° 2 : 443-448.

Neovermilia anoperculata , nouvelle espèce bathyale

de Nouvelle-Calédonie (Polychaeta, Serpulidae)

par Jean-Paul Lechapt

Résumé. — Neovermilia anoperculata sp. nov. est décrite à partir du matériel récolté au cours de la

campagne « Biocal ». Le principal caractère distinguant les individus observés des autres espèces du genre

est l’absence d’opercule.

Abstract. — Neovermilia anoperculata sp. nov. is described from material collected during the bathy-

abyssal cruise “ Biocal ” off New Caledonia (Pacific Ocean). The chief distinguish character of these

specimens is the lack of operculum.

J.-P. Lechapt, Laboratoire maritime de Dinard (MNHN), 17, avenue George V, 35801 Dinard, BP 28.

La campagne « Biocal » a eu lieu en 1985, à bord du « Jean Charcot », au large de la

Nouvelle-Calédonie. Parmi les Serpulidae récoltés, nous avons pu identifier quelques individus

appartenant au genre Neovermilia défini par Day (1961). Ce genre possède des soies

thoraciques simples, capillaires, semblables à celles du genre Vermiliopsis, mais il n’y a pas de

soies en faux du type « Apomatus ». L’absence d’opercule chez tous les spécimens examinés est

considérée comme un caractère spécifique et nous a conduit à décrire cette nouvelle forme

bathyale.

Le matériel-type est déposé au Muséum national d’Histoire naturelle, Paris (MNHN).

Neovermilia anoperculata n. sp.

Matériel examiné : Station DW 51 (31/08/85), 23°05'S-167°44'E-167°45'E, 680-700 m, 2 individus

(holotype et un spécimen incomplet); station CP 108 (09/09/85), 22°02'S-167°05'E-167°06'E, 335m.

10 individus (paratypes).

Description

L’holotype de la station DW 51 (MNHN UC 163) mesure 10 mm de longueur, dont 4 mm

pour le panache branchial. Celui-ci est constitué de 33 filaments (16 d’un côté, 17 de l’autre)

dont les extrémités s’enroulent sur elles-mêmes ce qui leur donne un aspect renflé. Il n’y a pas

d’opercule. La membrane thoracique dépasse le 7 e et dernier sétigère. L’abdomen comprend 30

à 40 sétigères (fig. 1).

- 444 —

Fig. 1. — Neovermilia anoperculata sp. nov. : individu entier, face ventrale.

Les soies du premier sétigère thoracique sont toutes capillaires et nettement frangées de

petites soies (pi. I, 1-2). Les soies des segments thoraciques suivants sont finement denticulées

(pi. I, 3-4); elles sont lisses à leur base, les denticulations n’apparaissant qu’aux 2/5 de leur

longueur et sur un seul côté de la soie ce qui leur confère une apparence limbée à faible

grossissement. Il n’y a pas de soies en faux du type « Apomatus ».

Les uncini thoraciques présentent une rangée simple de 5 dents (pi. Il, 1); les rangées

d’uncini se rejoignent presque à la face ventrale des derniers segments thoraciques (fig. 1).

Les segments abdominaux possèdent des soies géniculées et denticulées (pi. II, 2) et des

uncini présentant vers l’avant 4 à 6 dents disposées en une seule rangée et vers l’apex une

double rangée de 2 à 3 dents (pi. II, 3).

Les tubes sont blancs, lisses, solides, les plus gros ayant 3 mm de diamètre, ceux-ci

présentant quelques bourrelets plus ou moins saillants à l’extrémité antérieure (pi. III, 1-2).

Les dix paratypes de la station CP 108 (MNHN BOCAL A915) mesurent de 1,2 mm à

5 mm de longueur, le panache branchial non compris. Aucun ne porte d’opercule. Les

paratypes possèdent les mêmes types de soies et d’uncini que l’holotype. L’individu incomplet

de la station DW 51 n’est pas inclus dans la série des types.

445 -

Remarques

Les espèces de Neovermilia décrites jusqu’à présent possèdent un opercule : N. capensis

Day, 1961, de l’Afrique du Sud (Day, 1967); N. falcigera (Roule, 1898), de l’Atlantique

(Southward, 1963) et de l’océan Indien, présent au Plio-Pléistocène en Méditerranée

(Zibrowius et Hove, 1987); N. sphaeropomatus de Nouvelle-Zélande (Stull, 1979) et N.

globula (Dew, 1959) du sud-ouest de l’Australie. Neovermilia anoperculata s’en distingue donc

par l'absence d’opercule.

Remerciements

Je remercie J. Le Lannic du Centre Commun de Microscopie Électronique à Balayage de

l'Université de Rennes I et Y. Gruet du Laboratoire de Biologie Marine de l'Université de Nantes pour

les photos des tubes au MEB.

RÉFÉRENCES BIBLIOGRAPHIQUES

Day, J. H., 1961. — The polychaete fauna of South Africa. Part 6. Sedentary species dredged off Cape

coasts with a few records from the shore. J. Linn. Soc. Lond., Zool., 44 : 463-560.

1967. — A monograph on the Polychaeta of Southern Africa. Trustees British Museum Natural

History, Publ. no. 656 : 878 pp.

Dew, B., 1959. Serpulidae (Polychaeta) from Australia. Rec. Austr. Mus., 25 (2) : 19-56.

Roule, L., 1898. Notice préliminaire sur les espèces d’Annélides recueillies dans les explorations sous-

marines du « Travailleur » et du « Talisman ». Bull. Mus. Hist, nat., Paris, 4 : 190-195.

Southward, E. C., 1963. — Some new and little-known serpulid polychaetes from the continental slope.

J. mar. biol. 4m. U.K.. 43 : 573-587.

Stull, J., 1979. — Some benthic polychaetes from New Zealand. New Zealand oceanogr. Inst. Rec., 4

(5) : 25-43.

Zibrowius, H., et H. A. Hove, 1987. — Neovermilia falcigera (Roule, 1898) a deep- and cold-water

serpulid polychaete common in the Mediterranean Plio-Pleistocene. Bull. biol. Soc. Wash.. 7 : 259-

271.

— 446 —

Pl. I. — Neovermilia anoperculata sp. nov. : 1, soies du premier sétigère; 2, détail des soies du 1 er sétigère;

3, soies thoraciques ; 4, détail des soies thoraciques.

447

Pl. II.

Neovermilia anoperculata sp. nov. : 1, uncini thoraciques; 2, soies abdominales; 3, uncini abdominaux.

- 448 —

Pl. III. — Neovermilia imoperculata sp. nov. : 1-2, parties antérieures du tube.

Bull. Mus. natl. Hist, nat., Paris, 4 e sér., 14, 1992,

section A, n° 2 : 449-455.

Neotonchinae de la Baie de Morlaix

(Nematoda, Chromadorida)

par Nicole Gourbault et Magda Vincx

Résumé. Six espèces d’Ethmolaimidae ont été identifiées en Manche occidentale (Baie de

Morlaix), dont une nouvelle, Comesa platti sp. n. Portant à onze le nombre d’espèces de ce genre, cette

dernière est caractérisée par la taille très réduite des soies séphaliques, la position antérieure des amphides,

l'absence de différenciation latérale et les papilles précloacales au nombre de 9 à 11.

Abstract. Six species of the family Ethmolaimidae, including the new species Comesa platti sp. n.,

are identified from the Western part of the Channel (Baie de Morlaix). Within the genus Comesa, which

has eleven species at present, the new species is characterized by its short cephalic setae, the anterior

position of the amphids, the absence of lateral differentiation and the presence of 9-11 precloacal

supplements.

Key-words — Nématodes marins, Comesa, Manche.

N. Gourbault, Muséum national d’Histoire naturelle, URA 699 CNRS. Biologie des Invertébrés marins, 57, rue

Cuvier, F.75231 Paris cedex 05, France.

M. Vincx, University of Gent, Zoology Institute, Marine Biology Section, K. L. Ledeganckstraat 35, B.9000 Gent,

Belgium.

Introduction

Un suivi écologique des peuplements de nématodes marins de la Baie de Morlaix portant

sur plusieurs années (Gourbault, 1981, 1987) a permis la récolte de nombreux spécimens de la

sous-famille des Neotonchinae. Les espèces identifiées appartiennent aux deux genres

Neotonchus Cobb, 1933 et Comesa Gerlach, 1956, taxons toujours signalés dans la littérature

par un très faible nombre d’individus et dont la première révision a été effectuée par Wieser et

Hopper (1966) ; nous devons les plus récentes à Platt (1982, et 1985 sur ce même matériel de

la Baie de Morlaix).

Deux espèces de Neotonchus sont présentes : N. meeki Warwick, 1971 et N. boucheri Platt,

1982 décrites respectivement de la Mer du Nord (Northumberland) et de la Manche Ouest

(Pierre Noire, Morlaix). Les espèces de Comesa sont représentées par l’espèce-type, C.

corcunda Gerlach, 1956 et aussi par C. interrupta et C. votadiini (Warwick, 1971) encore

signalée en Mer du Nord (Heip, Herman & Vincx, 1983).

Mais l’espèce dominante est nouvelle; elle peuple l'ensemble du chenal de la Baie de

Morlaix avec toutefois une plus nette abondance aux stations moyennes, plus envasées, alors

que la seconde espèce en rang d’abondance, N. meeki, s’observe essentiellement dans la partie

sableuse, en aval du chenal.

- 450 -

Matériel et méthodes

Récoltes, tris et montages ont été effectués de façon classique et à présent standardisée

pour ce groupe (Vincx & Gourbault, 1988). Les spécimens-types ont été déposés dans les

collections nationales du Muséum national d’Histoire naturelle (MNHN) et du Zoology

Institute, Gent (RUG).

Famille Ethmolaimidae Filipjev et Stekhoven, 1941

Sous-famille Neotonchinae Wieser et Hopper, 1966

Genre COMESA Gerlach, 1956

[Syn. Neotonchoides Platt, 1982]

Comesa platti sp. n.

(Fig. 1)

Matériel-type : Holotype ç?l, lame BN 143 (MNHN); paratypes BN 144-155 (MNHN) et n° 10262-

10263 (RUG).

Localités : Baie de Morlaix, tout au long du chenal, essentiellement en amont (—15 m) mais aussi au

large (st. 7, cf. Gourbault, 1981).

Habitat : Marin, dans le sédiment sublittoral fin (50 < Md < 240 pim) et envasé (20 < % pélites <

50).

Étymologie : Espèce amicalement dédiée au Dr. Howard Platt, Department of the Environment,

Belfast, Northern Ireland, en reconnaissance de son travail de révision des Ethmolaimidae et en

remerciement pour l’intérêt qu’il a porté à ce matériel.

Mesures (longueurs en pim, moyennes et écart-types) :

Holotype c?l : ~ ^ ^ 620 680; a = 32,3; b = 7,5; c = 11,3; c' = 3,3.

O 17 zl 1 O

Paratypes : mâles (n = 26) : nb papilles précloacales = 10 + 1; L = 700 + 40; a = 29,9 ±

2,2; b = 7,9 ± 0,5; c = 11,8 ± 0,9.

Paratype dl : 19 75 ° pf 665 ; a = 26 ' 5 ; b = 7,8 ; c = 10,2; V = 49,6.

Femelles (n = 31) : V = 49,5 ± 1,4; L = 670 ± 54; a = 25,8 ± 3,2; b = 7,7 ± 0,5;

c = 10,2 ± 0,8.

Juvénile : I~ l 5 . ^ 560; a = 35; b = 7,5; c = 9,3.

o lo 10 1 j

Description

Mâles

Corps cylindrique avec atténuation plus nette dans la région postérieure que dans la partie

antérieure où elle est faible et confère un aspect carré à la tête. Cuticule à rangées transversales

resserrées (dix pour 5 [im) de très fines ponctuations arrondies et homogènes, débutant en

arrière des soies céphaliques et atteignant l’extrémité caudale; absence de différenciation

latérale (fig. IA).

Six minuscules papilles labiales internes peu visibles, six soies labiales externes et quatre

soies céphaliques papilliformes (lp.m); une paire de courtes soies subcéphaliques (1,5 p.m)

latéro-dorsales situées à 4-5 urn en arrière de l’amphide. Amphide spiralée à 2 1/2 tours, en

position assez antérieure, sa partie médiane atteignant le niveau des soies céphaliques, et de

4 |xm de largeur, soit 45 % du diamètre correspondant de la tête.

Cavité buccale moyennement développée avec petite dent dorsale pointue et deux paires

de denticules ventraux. Pharynx long (90p.m) et cylindrique avec un court bulbe terminal

ovoïde (17 x 14fj.m); cardia développé (9(xm). Anneau nerveux à 55 % de la longueur du

pharynx. Glande excrétrice ventrale volumineuse ouvrant par un très petit pore ventral, situé

au niveau des soies céphaliques, suivi d’une longue (24 x 4[xm) ampoule très antérieure

(fig. IB). Intestin à longues cellules dans sa partie antérieure.

Queue typique de Neotonchinae, légèrement recourbée ventralement (fig. IG).

Mâle diorchique à testicules en tandem, antérieur droit, court, épais, débutant à une

centaine de jj.m en arrière de la base du pharynx et placé le plus souvent à la gauche du tube

digestif ; testicule postérieur toujours moins développé, réfléchi, ce qui peut donner l’impres¬

sion que les testicules sont opposés (fig. 1C). Longues vésicules séminales à spermatozoïdes

globuleux, très granuleux (10-12 jim). Vas deferens à cellules granuleuses également, mais les

granulations sont plus petites et de taille hétérogène en général, à l’exception de deux zones :

juste en avant de la première papille précloacale, et aussi avant le « clear patch » au niveau des

3-4 e papilles.

Spicules pairs, coudés dans leur tiers postérieur, à pointe effilée et capitulum légèrement

évasé, long de 24-25 jim, soit 1,5 fois la longueur du diamètre corporel au niveau de l’anus.

Gubernaculum (17-18 pan) en deux lames minces à partie proximale effilée et distale à peine

recourbée, s’écartant des spicules en arrière de la courbure. Une soie préanale (3 jxm) à une

dizaine de p.m en avant du pore cloacal précède la série des papilles précloacales situées à égale

distance les unes des autres, soit 12;xm, et au nombre de neuf à onze généralement (douze

papilles chez deux des mâles). Ces cupules à ouverture circulaire présentent en outre l'étroit

bourrelet longitudinal articulé caractéristique du groupe (fig. 1G-H).

Femelles

Elles diffèrent essentiellement des mâles par la morphologie de la queue (c' = 3,6 au lieu

de 3,3).

Didelphes, à ovaires opposés et réfléchis; vagin entouré d’une forte musculature et

accompagné de deux petites glandes sphériques granuleuses. Chambre utérine impaire peu

•• — Comesa platti sp. n. Holotype cjl : A, partie antérieure en vue latérale superficielle et B, en coupe optique

sagittale, C, habitus. Paratype femelle $1 : D, système reproducteur, E, partie antérieure en coupe optique et F,

partie postérieure. G, appareil copulateur et queue du Jl. H, vue ventrale de la partie postérieure d'un paratype

mâle au niveau des papilles cloacales.

453

développée et spermathèques renfermant de gros spermatozoïdes analogues à ceux des

vésicules mâles, en nombre relativement réduit du fait de leur grande taille. Présence de

corpuscules globuleux réfringents au départ des oviductes (fig. 1D).

Juvéniles à habitus semblable à celui des adultes.

Diagnose différentielle : La nouvelle espèce, Comesa platti sp. n., est caractérisée par la taille très

réduite des soies céphaliques, la morphologie de l’amphide et le nombre de papilles précloacales ; pas de

différenciation latérale de la cuticule. Ces traits la rapprochent essentiellement de C. interrupta ; chez cette

dernière espèce, les spicules sont légèrement plus longs (27-28 um) mais de forme nettement différente, le

gubernaculum est moins développé, et les papilles précloacales sont plus petites. L’ornementation

cuticulaire consiste encore en ponctuations plus espacées chez la nouvelle espèce.

Comesa votadinii (Warwick, 1971)

(Fig. 2)

Neotonchus votadinii Warwick, 1971 : 105-106, fig. 6 (ljJ, 1Ç).

C. votadinii ; Platt, 1985 : 148, fig. 9.

Matériel étudié : 10dd, 2ÇÇ, 1 juv., lames AN 659-662, 665-667 (MNHN) et n° 10264-10265

(RUG).

Localités : Baie de Morlaix, tout au long du chenal.

Habitat : Marin, dans le sédiment fin à moyen (55 < Md < 650 p.m) et envasé (11 < % pélites <

50) du chenal.

Mesures (longueurs en gm) :

Mâles : cJl : ? ^ ^’ Q -790; a = 27,2; b = 6,8; c = 9,9; c' = 3. — (n = 9) : nb :

papilles précloacales 14 (13-15); L = 765 (650-830); a = 27,0 (21-33,2); b = 6,9 (6,5-7,6); c =

10,4 (9,4-11,8); long, spicules = 34 (31-38).

Femelles : $1 : ~ 790; a = 22,5; b = 7,6; c = 11,6; V = 50,6. — $2; L =

870; a = 23,1; b = 7,0; c = 9,5; V = 51,1.

Remarques

Cette espèce, décrite sur deux individus et dont quelques exemplaires du chenal ont été

confrontés au spécimen-type par Platt (1985), est bien caractérisée par l’amincissement de

l’extrémité antérieure et le rapprochement des deux dernières couronnes de papilles labiales

externes et soies céphaliques, mais aussi par la largeur de l’amphide occupant 60% du

diamètre céphalique à ce niveau. La paire de soies subcéphaliques est située en arrière de

l’amphide. La ponctuation consiste en points assez gros et espacés (10 rangs pour 10 [im) et

comme chez C. platti, aucune différenciation latérale n’existe. Le bulbe pharyngien présente

également une forme en losange caractéristique.

Le système copulateur est bien identifiable, spicules pairs et arqués à capitulum marqué,

gubernaculum en lames (fig. 2D).

455 —

En revanche, les femelles sont assez difficiles à différencier de celles de C. platti.

Cependant, l’amphide est ici proportionnellement plus petite, la queue plus trapue (c' = 2,5 au

lieu de 3,6), les spermatozoïdes contenus dans futérus sont de taille deux fois moindre (4-5 jam

au lieu de 10-12p.m) et il n’existe pas de corpuscules réfringents dans l’oviducte.

Le nouveau taxon porte à onze le nombre d’espèces de Comesa décrites à ce jour : C.

corcunda Gerlach, 1956, C. cuanensis (Platt, 1982), C. cupulata (Vitiello, 1970), C. interrupta

(Warwick, 1971), C. melotrida (Wieser et Hopper, 1966), C. platti sp. n., C. pseudocorcunda

(Vitiello, 1971), C. vida (Warwick, 1971), C. vitielloi (Platt, 1982), C. votadinii (Warwick, 1971)

et C. warwicki (Platt, 1982).

RÉFÉRENCES

Cobb, N. A., 1933. — New nemic genera and species, with taxonomie notes. (Ed. by Margaret V. Cobb.)

J. Pcirasit., 20 (2) : 81-94.

Filipjev, F, & J. H. Schuurmans Stekhoven, 1941. A manual of agricultural helminthology. Leiden

(E. Brill) : 1-878.

Gerlach, S., 1956. Diagnosen neuer Nematoden aus der Kieler Bucht. Kieler Meeresforsch., 12 : 85-

109.

Gourbault, N., 1981. — Les peuplements de Nématodes du chenal de la Baie de Morlaix (Premières

données). Cah. Biol, mar., 22 (1) : 65-82.

1987. - Long-term Monitoring of Marine Nematodes Assemblages in the Morlaix Estuary

(France) Following the Amoco Cadiz Oil Spill. Estuar. Coast Shelf Sci., 24 : 657-670.

Heip, C., R. Herman & M. Vincx, 1983. — Subtidal meiofauna of the North Sea : A review. Biol. J.

Dodonaea, 51 : 116-170.

Platt, H. M., 1982. — Revision of the Ethmolaimidae (Nematoda : Chromadorida). Bull. Br. Mus. nat.

Hist., (Zool.), 43 (4) : 185-252.

1985. - Further observations on the Ethmolaimidae (Nematoda : Chromadorida). J. Nat. Hist.,

19 : 139-149.

Vincx, M., & N. Gourbault, 1989. — Two new species of Morlaixia gen. n. (Nematoda, Diplopeltidae)

with a subterminal ventral mouth. Bull. Mus. natn. Hist, nat., Paris, 4 e sér., 10 , 1988, sect. A, (4) :

711-718.

Vitiello, P., 1970. - Nématodes libres marins des vases profondes du Golfe du Lion. IL Chromadorida.

Téthys, 2 (2) : 449-500.

1971. — Nématodes nouveaux des vases terrigènes côtières des côtes provençales. Téthys, 2 (4) :

859-876.

Warwick, R. M., 1971. — The Cyatholaimidae (Nematoda, Chromadoroidea) off the coast of

Northumberland. Cah. Biol, mar., 12 : 95-110.

Wieser, W., & B. Hopper, 1966. The Neotonchinae, new subfamily (Cyatholaimidae : Nematoda),

with an analysis of its genera, Neotonchus Cobb, 1933 and Gomphionema new genus. Can. J. Zool.,

44 : 519-532.

Bull. Mus. natl. Hist, nat., Paris, 4 e sér., 14, 1992,

section A, n° 2 : 457-472.

Un genre oublié d’Atractosomatinae des Alpes italo-suisses,

Bomogona Cook, 1895 : statut, contenu, chorologie

(Diplopoda, Craspedosomatida)

par Ariane Pedroli-Christen et Jean-Paul Mauriès

Résumé. — La redécouverte fortuite des échantillons-types à’ Atractosoma lombardicum Brôlemann,

1892, espèce-type du genre oublié Bomogona Cook, 1895, au Muséum national d’Histoire naturelle de

Paris, permet une mise à jour nomenclaturale qui vient à point nommé compléter une révision

systématique et chorologique s’appuyant sur d’abondantes récoltes effectuées récemment dans le Valais et

le Tessin. Des taxons traditionnellement et confusément considérés comme appartenant aux genres ou

sous-genres Atractosoma Fanzago, 1886, Ceratosoma Verhoeff, 1897, Triakontazona Verhoeff, 1897,

Linmalpium Verhoeff, 1921, Asandalum Attems, 1949 et plus récemment aux genres Ochogona Cook, 1895

et Omithogona Cook, 1896, géographiquement cantonnés au sud de la Suisse et au nord-ouest de l’Italie,

appartiennent en fait à un seul genre, Bomogona Cook, 1895, et à deux espèces : Bomogona lombardica

(Brôlemann, 1892) [syn. nov. : Ceratosoma luganensis et luganensis ruscorum Verhoeff, 1921, Ceratosoma

fonds Verhoeff, 1932]; Bomogona ( Ornithogona ) helvetica (Verhoeff, 1894) [syn. nov. : Atractosoma

helveticum dentatum Faës, 1902, Ceratosoma verbani Verhoeff, 1910, et Dorasoma quercuum Verhoeff,

1932],

Abstract. — The revision of the type of Atractosoma lombardicum , type-species of the forgotten

genus Bomogona Cook, 1895, in collection at the Muséum national d’FIistoire naturelle of Paris, and the

analysis of abundant material recently collected in Switzerland, allowed a nomenclatorial, systematic and

chorological revision of the taxa successively and confusedly called Atractosoma Fanzago, 1886,

Ceratosoma Verhoeff, 1897, Triakontazona Verhoeff, 1897, Limnalpium Verhoeff, 1921, Asandalum

Attems, 1949, Ochogona Cook, 1895 and Ornithogona Cook, 1896. These are revised to a single genus,

Bomogona Cook, 1895, and two species : Bomogona lombardica (Brôlemann, 1892) [syn. nov. :

Ceratosoma luganensis et luganensis ruscorum Verhoeff, 1921, Ceratosoma fonds Verhoeff, 1932];

Bomogona (Ornithogona) helvetica (Verhoeff, 1894) [syn. nov. : Atractosoma helveticum dentatum Faës,

1902, Ceratosoma verbani Verhoeff, 1910, and Dorasoma quercuum Verhoeff, 1932]. These species are

distributed in the southern part of Switzerland and in the north-west of Italy.

A. Pedroli-Christen, Musée d’Histoire naturelle, CH-2000 Neuchâtel.

J.-P. Mauriès, Laboratoire de Zoologie (Arthropodes), Muséum national d'Histoire naturelle, 61, rue Buffon, F-75005

Paris.

Introduction

Les nombreux articles qui traitent de certaines espèces de Diplopodes Craspedosomides

de Suisse et du nord de l’Italie autrefois classées dans les genres Euceratosoma Verhoeff, 1897

(alias Ceratosoma Verhoeff, 1897) ou Atractosoma, et plus récemment dans les genres

Ornithogona Cook, 1896, Ochogona Cook, 1895, Triakontazona Verhoeff, 1897, Linmalpium

458 —

Verhoeff, 1921, Dorasoma Verhoeff, 1932 et Asandalum Attems, 1949 font ressortir une

certaine confusion et des contradictions qui rendent nécessaire une clarification des problèmes

nomenclaturaux et taxonomiques afférant à ces taxons.

C’est pourquoi nous avons procédé, d’une part, à une approche historique des données et,

d’autre part, à la comparaison des récoltes effectuées par l’un de nous (A. P.) avec les matériels

types.

Dans le cadre volontairement limité de cette note, ne seront considérés ici que des

Atractosomatinae ayant été classés dans les taxons de rang générique énumérés ci-dessus.

Nous verrons plus loin qu’ils appartiennent en fait à un seul genre, géographiquement localisé

à l’ensemble formé par le Valais, le Tessin, l’Aoste, le Piémont et la Lombardie (avec une

pointe avancée méridionale vers le Nord-Appenin).

Matériel et méthodes

L’un de nous (A. P.), au cours de ces dernières années, a récolté personnellement ou

rassemblé pour identification (dans le cadre d’études pluridisciplinaires), en Suisse, et plus

particulièrement dans le Valais et le Tessin, par chasse à vue et par piégeage (Barber),

240 exemplaires adultes d’Atractosomatinae se rattachant aux taxons évoqués ci-dessus. Cet

important matériel, récolté dans 20 stations pour la plupart inédites, a été comparé, pour

identification, avec les figures et descriptions des auteurs, mais aussi avec les matériels des

collections ci-après :

Collection Verhoeff, de la Staatssammlung de Munich : Ceratosoma luganensis Verhoeff, 1921 :

1 mâle, 1 femelle de Borgotaro, 1 mâle de Torre Pellice, 1 mâle de Toron (Como), 1 femelle de Campo di

Fiori (Varese), 2 mâles de Ceres; Ceratosoma luganensis ruscorum Verhoeff, 1921 : 1 mâle, 2 femelles de

Como; Ceratosoma verbani Verhoeff, 1910 : 1 mâle, 1 femelle de Bellinzona; Dorasoma helveticum

(Verhoeff, 1894) : 16 mâles, 6 femelles de Stalden (850 et 900 m) et 1 mâle, 9 femelles de Zermatt

(1750m); Dorasoma serratum Verhoeff, 1932 : 1 mâle, 2 femelles d’Aoste; Dorasoma quercuum Verhoeff,

1932 : 1 mâle d’Ivrea; Ceratosoma larii Verhoeff, 1921 : 1 mâle, 3 femelles de Bellano.

Collection du Muséum national d’Histoire naturelle de Paris : Les échantillons originaux ayant

servi à la description de Atractosoma lombardicum Brôlemann, 1892 ont été retrouvés à la faveur de

rangements entrepris récemment. Des 10 individus (6 mâles et 4 femelles) cités par l’auteur de la localité

originale (environs de Varese), n’ont été retrouvés que 4 mâles, 3 exemplaires sans partie antérieure et une

femelle préadulte. Du matériel cité par Brôlemann dans sa deuxième note sur la Lombardie en 1895, ont

pu être examinés : 3 exemplaires dont 1 mâle de Erba (Como), 11 jeunes de Lecco (Como), 1 femelle du

Monte Resegone (Como), 1 femelle du Val Ganna (Varese).

— Collection Faës du Muséum d’Histoire naturelle de Lausanne : Atractosoma helveticum dentatum ,

représenté par un mâle disséqué aux gonopodes malheureusement perdus.

Autres matériels : Quelques échantillons étudiés par l'un de nous (J.-P. M.), appartenant à des

localités inédites, figurent dans ce travail ; ils proviennent, soit d'inédits provenant des collections du

Muséum national d’Histoire naturelle de Paris, soit de récoltes effectuées par Desmond Kime (Bruxelles)

ou rassemblées par Marco Valle (Musée de Bergamo).

I. Historique

Brôlemann (1892 : 108, fig. 6) décrit Atractosoma lombardicum sur 6 mâles et 4 femelles

récoltés en deux localités des environs de Varese (Vedano-Olona et Gavirate). Cette espèce,

— 459 -

bien que citée une deuxième fois par Brôlemann (1895), qui donne de nouvelles localités

lombardes (Val Ganna, Erbe, Lecco, Monte Resegone, Comune) va rester, probablement en

raison de l’insuffisante clarté des dessins des gonopodes, complètement ignorée de la quasi¬

totalité des auteurs.

Ainsi, Verhoeff (1894) n’y fait aucune allusion et ne la compare pas à son Atractosoma

helveticum (p. 286, fig. 1-3), décrit sur un mâle récolté à Zermatt.

Par contre, Cook (1895 : 2) estime sans doute la description de l’espèce de Brôlemann

suffisante puisqu’il la désigne, certainement sans en avoir vu un seul échantillon, comme type

d’un nouveau genre Bomogona. Création qu’il effectue en même temps que plusieurs autres

(dont Ochogona pour Atractosoma pusillum Verhoeff, 1893), sur la base des seules descriptions

d’espèces qui en l’occurrence tiennent lieu de diagnose. De la même façon il crée, un peu plus

tard (Cook, 1896 : 8), Ornithogona , pour Atractosoma helveticum Verhoeff, 1894.

De son côté, Verhoeff (1897 : 131), ignorant les travaux de son collègue américain, dont

on sait que la diffusion a été très confidentielle, inclut cette dernière espèce, dont il est

l’inventeur, dans un nouveau genre Triakontazona (dans lequel il classe aussi pusillum). Dans le

même travail, à la même page, il crée un autre genre, Ceratosoma (type apfelbecki n. sp.) qui

englobera plus tard (Verhoeff, 1899 : 140-141) Triakontazona relégué au rang de sous-genre 1 .

Faës (1902 : 83, fig. 27-30), probablement non informé de ces péripéties, continue à

utiliser le nom de genre Atractosoma et décrit du Valais (Ardon et Mauvoisin) une nouvelle

forme, dentatum, qu’il considère comme sous-espèce de A. helveticum et qui se distingue, selon

lui, par la présence, à l’apex des syncoxites des gonopodes, d’une structure en lamelle

denticulée non signalée dans la description du type par Verhoeff, (1894).

Verhoeff (1910 : 314, fig. 124-127) décrit sur un seul mâle, de Laveno (Lac Majeur),

Ceratosoma (Triakontazona ) verbani qui ressemble beaucoup à helveticum tant par sa

morphologie externe que par sa structure gonopodiale; il signale de petites différences aux

cheirites et aux syncoxites.

Verhoeff (1921 : 27-29, fig. 20-26) décrit trois taxons dont l’un est pratiquement

sympatrique de l’espèce de Brôlemann : Ceratosoma larii , récoltée à Bellano et à Rovinato,

près de Lecco (lac de Corne), ne sera jamais plus citée dans la littérature hormis dans des listes

(Attems, 1949; Strasser et Minelli, 1984); Ceratosoma luganensis, récoltée en Suisse à

Melide, près de Lugano (Tessin), avec une sous-espèce C. /. ruscorum, récoltée en territoire

italien à Como, sera par contre retrouvée et citée plusieurs fois par la suite.

Dans la même note, Verhoeff classe ces taxons, avec C. helveticum (incluant son nouveau

syn. dentatum Faës) et C. verbani, dans un nouveau sous-genre de Ceratosoma : Limnalpiun. Il

apporte quelques précisions sur la structure gonopodiale de C. verbani (fig. 27) dont il a récolté

cinq mâles et cinq femelles à Bellinzona (Tessin) : il signale au coxosternite des paragonopodes

des prolongements paramédians qui sont absents chez C. helveticum.

Attems (1927 : 105), à l’occasion de la description de deux espèces d’Autriche et de

Yougoslavie, valide le sous-genre Limnalpium Verhoeff, 1921 en désignant comme espèce-

type : A. helveticum', il lui conserve le même contenu que Verhoeff (1921) : verbani,

helveticum, larii, luganense.

Verhoeff (1932 : 604-606, fig. 15-20) crée un nouveau genre Dorasoma pour deux espèces

1. Pour remplacer Ceratosoma, nom deux fois préoccupé, ont été proposés d'une part Ceratosomana Strand, 192S

et d'autre part Euceratosoma Verhoeff, 1897 (validé par Jeekel, 1971).

460 -

nouvelles récoltées en Val d’Aoste : D. serralum (Aoste) et D. quercuum (Ivrea, près du Lac

Sirio). Pour son inventeur, ce genre se distingue de Limnalpium, dont il est très proche, par la

présence d’une lame dentée sur les syncoxites des gonopodes. Dans ce même travail, il décrit

(p. 607, fig. 21-23) une nouvelle espèce récoltée à Torre Pellice (Piémont) : C. (Limnalpium )

fonds.

Verhoeff (1936a : 206-207), s’appuyant sur de nouvelles récoltes effectuées dans le Haut-

Valais (p. 214 : Zermatt, vallée de Saas à Stalden, Visp), décèle pour la première fois chez C.

( L .) helvedcum la lame dentée des syncoxites gonopodiaux déjà décrite et figurée par Faës

(1902) pour sa forme dentatum : il considère ce caractère comme très important et

caractéristique du genre Dorasoma qu’il avait créé en 1932 pour les deux « espèces » quercuum

et serratum, auxquelles il ajoute helvedcum.

Verhoeff (1936Z> : 404), à la faveur de nouvelles récoltes effectuées au Piémont (Felsen

près Ceres, Ala di Stura, Pinerolo, Barge) et dans le Nord-Appenin (Borgotaro), s’aperçoit que

son C. (L.) fonds est en fait synonyme de C. (L.) luganensis Verhoeff, 1921.

Dans la liste des taxons est-alpins donnée par Attems (1949 : 137)), apparaît un nouveau

nom de genre, Asandalum , créé probablement avec l’intention louable (mais inutile puisqu’il

existait Euceratosoma Verhoeff, 1899) de remplacer Ceratosoma (nom deux fois préoccupé!).

Parmi les 27 taxons regroupés par Attems sous ce nom de genre, nous retrouvons luganensis,

verbani, quercuum et larii.

Strasser (1978 : 151) signale dans la plaine du Piémont Dorasoma helvedcum (Verh.,

1894) pr. quercuum Verh., 1932 (Castelleto Ticino); pour lui, D. serratum et D. quercuum ne

sont pas des espèces. Il signale également dans la même région (Lombardore), mais aussi dans

les Alpes Graies (Torre del Colle), la présence de Triakontazona ( Limnalpium ) luganense

Verhoeff, 1921.

Hoffman (1979 : 125) trouve injustifié le long oubli dans lequel est restée l’espèce-type de

Bomogona, Atractosoma lombardicum, et précise qu’il ne peut, avant toute révision, se

prononcer clairement sur la place de Bomogona parmi les autres taxons de rang générique de la

sous-famille des Atractosominae.

Ceci explique pourquoi dans la liste des Diplopodes d’Italie de Strasser et Minelli

(1984) où sont adoptées, au niveau des genres, les options nomenclaturales proposées par

Hoffman (1979), Bomogona lombardicum n’apparaît pas. Les autres taxons qui nous

intéressent ici sont classés, l’un ( helvedca ) dans le genre Ornithogona, les autres ( verbani,

luganensis et larii) dans le genre Ochogona.

Kurnik (1896) décrit les caractères de la femelle à.'Ochogona luganensis sur du matériel

provenant de la collection Verhoeff (Staatssamml. München); il s’agit de spécimens signalés

par Verhoeff (1936) du Nord-Apennin (Borgotaro) sous le nom de Ceratosoma (Limnalpium)

luganensis.

La seule revue de cette bibliographie, avant même tout examen de matériel, permet de

dresser (ci-après) une liste provisoire de cinq groupes de citations et/ou mentions de taxons

manifestement synonymes. Ceux qui ne sont que des combinaisons de noms sont indiqués par

un astérisque.

1 — Atractosoma lombardicum Brôlemann, 1892

Atractosoma lombardicum Brôlemann, 1895

* Bomogona lombardica Cook, 1895

* Bomogona lombardicum Hoffman, 1979

— 461 —

2 — Atractosoma helveticum Verhoeff, 1894

*Ornithogona helvetica Cook, 1895

*Triakonla:ona helvetica Verhoeff, 1897

Atractosoma helveticum dentatum Faës, 1902

*Ceratosoma ( Limnalpium ) helveticum Verhoeff, 1921

*Ceratosoma (Limnalpium) helveticum Attems, 1927

Dorasoma quercuum Verhoeff, 1932

Dorasoma serratum Verhoeff, 1936

Dorasoma helveticum Verhoeff, 1936

*Asandalum quercuum Attems, 1949

Dorasoma helveticum quercuum Strasser, 1978

*Ornithogona helvetica Strasser et Minelli, 1984

3 — Ceratosoma (Triakontazona) verbani Verhoeff, 1910

Ceratosoma (Limnalpium) verbani Verhoeff, 1921

Ceratosoma (Limnalpium) verbani Attems, 1927

*Asandalum verbani Attems, 1949

*Ocltogona verbani Strasser et Minelli, 1984

4 — Ceratosoma (Limnalpium) larii Verhoeff, 1921

Ceratosoma (Limnalpium ) larii Attems, 1927

* Asandalum larii Attems, 1949

*Ochogona larii Strasser et Minelli, 1984

5 — Ceratosoma (Limnalpium) luganensis Verhoeff, 1921

Ceratosoma (Limnalpium) luganensis ruscorum Verhoeff, 1921

Ceratosoma (Limnalpium) luganensis Attems, 1927

Ceratosoma (Limnalpium) fontis Verhoeff, 1932

* Asandalum luganense luganense Attems, 1949

* Asandalum luganense ruscorum Attems, 1949

*Triakontazona (Limnalpium) luganense Strasser, 1978

*Ochogona luganensis Strasser et Minelli, 1984

1*Ochogona luganensis Kurnik, 1986

Du seul point de vue nomenclatural, l’affiliation générique des groupes de taxons 1 et 2 ne

pose aucun problème puisque chacun des deux contient une espèce-type de genre : Bomogona

pour le premier, Ornithogona pour le deuxième. Le groupe 3 ne contient qu’une seule espèce,

manifestement voisine sinon synonyme d’ Ornithogona helvetica , qu’il est donc logique de

classer, comme ne l’ont pas fait les auteurs récents, dans le même genre que le groupe 2, c’est-

à-dire Ornithogona. La place des groupes 4 et 5 est moins évidente : larii et luganensis , si l’on

en juge par les figures de Verhoeff (1921), semblent distinctes; elles sont cependant

manifestement proches l'une de l’autre et les auteurs récents ont donc eu raison de les

considérer comme congénériques ; mais c’est une étude systématique telle que celle que nous

avons menée, et dont les résultats sont exposés plus loin, qui pouvait seule nous dire si le choix

qu’ils ont fait d 'Ochogona était le bon. Cette étude nous éclairera aussi sur les synonymies que

l’on pouvait supposer entre : larii et luganensis (p. 465) ; helvetica et verbani (p. 462) ;

lombardica et luganensis (p. 462); Bomogona et Ornithogona (p. 467).

- 462 —

II. Morphologie comparée des gonopodes

1. Taxons helvetica, verbani, quercuum et serratum

91 mâles se rattachant à ce groupe de taxons (nos groupes 2 et 3), en provenance de

23 localités situées dans le Valais et le Tessin, ont été récoltés ces dernières années. Tous ont

une structure des gonopodes semblable ; les syncoxites (S) des gonopodes antérieurs présentent

toujours la lamelle dentée caractéristique, signalée pour la première fois par Faës, qui pour elle

créa sa « forme » dentatum , et pour laquelle Verhoeff créera plus tard son genre Dorasoma.

Tous ces exemplaires de Suisse présentent également des prolongements paramédians (P) sur le

coxosternum des paragonopodes.

Parmi ces spécimens, ceux provenant du Tessin ont été comparés aux mâles (deux

préparations) de verbani, que Verhoeff avait récoltés à Bellinzona. Rien ne permet de les

distinguer les uns des autres. En effet sur les préparations de Verhoeff, les syncoxites (S) des

gonopodes présentent sans aucun doute possible la lame dentée signalée plus haut et que,

curieusement, Verhoeff n’avait pas observée ni décrite, comme elle lui avait échappé lorsqu’il

avait décrit helvetica en 1894.

Les autres différences signalées par Verhoeff (1910 et 1921) entre helvetica et verbani se

situent, pour les gonopodes antérieurs, au niveau des dents terminales du cheirite (C) : elles

sont plus ou moins écartées et plus ou moins larges ; au niveau des paragonopodes, il y a

présence ou absence de prolongements paramédians sur le coxosternum. L'examen des

91 mâles montre que ces différences observées aux cheirites et aux prolongements médians du

gonopode sont le fait de variations individuelles qui sont très importantes — elles ne sont dues

qu’en partie à l'orientation des objets sur lame microscopique — et englobent donc les

« caractéristiques » de verbani. Quant aux prolongements paramédians des paragonopodes, il

s’agit de formations membraneuses paires ou impaires, plus ou moins transparentes et qui

pourraient être invaginables comme des sacs coxaux.

Pour les mêmes raisons, une analyse comparée attentive des préparations de Verhoeff de

serratum, quercuum et helveticum ne permet pas non plus de distinguer ces trois taxons.

La synonymie est évidente entre nos groupes de taxons 2 et 3, qui appartiennent tous à

l’espèce « Atractosoma » helveticum Verhoeff, 1894.

Nous avons figuré ici (fig. 1-6) les pièces gonopodiales d’un mâle de Melera (Val

Morobbio) pour montrer, en ce qui concerne les gonopodes antérieurs, l'importance de

l’orientation tant au niveau du cheirite (C, fig. 1, fig. 2 à 5), que du syncoxite (S, fig. 1); sur ce

dernier on voit que, selon l’orientation des deux moitiés, on peut observer ou non les

denticulations et comprendre pourquoi elles avaient à un moment échappé à Verhoeff.

2. Taxons lomhardicum et luganensis

Révision à’Atractosoma lombardicum Brôlemann, 1892.

Localité-type : Italie, Lombardie, Varese, Vedano-Olona et Gavirata, octobre 1887, coll.

H. W. Brôlemann, 1 mâle lectotype (désigné ici), 3 mâles, 1 femelle préadulte, 3 exemplaires paralectoty-

pes (coll. Myriapodes du MNHN, Paris, n° DA 080).

Fig. 1-6. — Bomogona (Ornithogona) helvetica Verhoeff, 1894, mâle de Melera : 1, gonopodes (P.8) en vue caudale de

biais montrant le syncoxite (S) et le cheirite (C) droit ; 2, cheirite droit en vue externe orale ; 3, cheirite gauche en

vue orale; 4, le même en vue externe; 5, le même en vue externe distale; 6, paragonopodes (P.9).

— 465 —

Localités citées par Brôlemann (1895) (matériel retrouvé au MNHN, Paris) : Italie, Lombardie,

Como : Monte Resegone (près Lecco), 14.08.1892, coll. H. W. Brôlemann : 1 femelle jeune à

28 anneaux); Lecco, 31.07.1892, coll. H. W. B. : 1 mâle jeune, 10 jeunes; Erba, 29.08.1891, coll.

H. W. B. : 1 mâle, 1 mâle j., 1 exemplaire. — Italie, Lombardie, Varese : Val Ganna, 8.02.1888, coll.

H. W. B. : 1 femelle j.

Localité citée par Brôlemann (1892) (matériel non retrouvé) : Italie, Lombardie, Varese :

Comune.

La description originale des caractères externes est suffisamment précise pour qu’il soit

inutile d’y revenir ici. Cependant, pour les paranota des anneaux moyens, dont le texte et la

figure 6a de Brôlemann (1892) ne donnent qu’une idée imparfaite, il nous a paru nécessaire de

donner de nouvelles figurations (fig. 9 et 10) qui permettent de mieux évaluer les distances

relatives qui séparent les macrochètes les uns des autres.

Les gonopodes (fig. 11-18) et notamment la silhouette des cheirites (C, fig. 11 et fig. 14-

17), vus et dessinés sous différents angles, permettent d’établir sans ambiguité la conspécificité

de lombardicum et du luganensis dessiné par Verhoeff (1921), ce qui ne pouvait se faire au vu

des dessins de Brôlemann (1892), non seulement parce que ces dessins sont petits et imprécis,

mais aussi parce que l’angle sous lequel Brôlemann avait dessiné les cheirites ne pouvait que

dérouter les comparaisons.

Discussion

Il est manifeste que le matériel récolté ces dernières années et jusqu’à ce jour identifié par

nous comme luganensis, identification s’appuyant sur les travaux de Verhoeff mais aussi sur le

matériel de sa collection, doit, maintenant que lombardica est connu, être rapporté à cette

espèce. D’autre part, il faut noter que dans les préparations microscopiques définitives telles

que celles montées par Verhoeff, il est impossible d’avoir une idée de la tridimensionalité des

pièces gonopodiales, ce qui a entraîné des erreurs d’interprétation de la part de Verhoeff lui-

même; c’est le cas pour Ceratosoma (L.) fonds que Verhoeff décrivit en 1932 et qu’il mit en

synonymie avec luganensis quatre ans plus tard, en 1936. La création de ruscorum en 1921

ressort probablement d’une semblable méprise, mais aussi peut-être d’une conception

différente de celle que nous avons aujourd’hui des limites des variations intraspécifiques.

En conséquence de ce qui précède, il faut regrouper dans la même synonymie les taxons

énumérés dans nos groupes 1 et 5; tous appartiennent à l’espèce « Atractosoma » lombardica.

3. Taxons larii et luganensis

L’examen de l’unique préparation de larii du seul mâle conservé dans les collections de

Munich, que nous avons eu sous les yeux, ne nous en apprend malheureusement pas plus que

l’examen des figures publiées par Verhoeff (1921). S’il est manifeste que larii est plus proche

de lombardica que de helvetica, nous sommes dans l’incapacité de décider aujourd’hui si larii

est une espèce valide ou une sous-espèce de lombardica , ou représente seulement des

morphotypes un peu dérivés du fait de leur position externe dans faire de cette espèce (voir

fig. 19). Nous lui laissons provisoirement le statut de sous-espèce de lombardica, et notre

groupe 4, qu’elle constituait, doit donc se retrouver avec les groupes 1 et 5.

- 467 -

III. Morphologie comparée des vulves

La seule femelle retrouvée dans le matériel original de lombardica n’est pas adulte

(28 anneaux) et a été récoltée dans une station qui se trouve sur le territoire de larii (à l’est du

lac de Côme); il faut certainement la rapporter à ce taxon.

Pour connaître les caractères vulvaires de cette espèce, il faut se reporter aux photos et

dessins de vulves donnés par Kurnik (1986), qui ont été réalisés sur les échantillons du Nord-

Appenin identifiés comme luganensis par Verhoeff (1936). La femelle que nous avons

examinée provient du Tessin (Stabio); ses vulves ne se distinguent pas fondamentalement de

celles dessinées par Kurnik ; seul, le mamelon spinigère externe paraît ici plus postérieur, peut-

être parce que l’angle d’observation est différent.

Quant aux vulves de helvetica, elles n’étaient pas encore connues. La figure 8 représente la

vulve gauche d’une femelle récoltée à Melera (Val Morobbio); les ressemblances avec les

vulves de lombardica sont évidentes, y compris par la position du mamelon spinigère (m), et

elle ne se distingue que par la présence d’un lobe caudal interne (n) nettement individualisé

dans la partie caudale de la valve interne.

IV. Synonymies

Des paragraphes qui précèdent, il s’ensuit que nous nous trouvons en définitive en

présence de seulement deux taxons de rang spécifique, l’un Bomogona lombardica représenté

par nos groupes de synonymes L 4 et 5, l’autre, Ornithogona helvetica par nos groupes 2 et 3.

Chacun de ces taxons est type d’un nom de genre. Cependant, si ces deux espèces sont bien

caractérisées morphologiquement l’une par rapport à l’autre, il ne nous semble pas justifié de

les considérer comme appartenant à deux genres distincts. Néanmoins, compte tenu des

« distances » qui séparent les différents genres d’Atractosomatinae, nous considérons ici

Ornithogona Cook, 1896, comme sous-genre de Bomogona Cook, 1895, et nous proposons

donc ici, en attendant la révision d’autres taxons très proches (tels les Oroposoma Verhoeff,

1936), la liste synonymique suivante :

Bomogona Cook, 1895

Espèce-type : Atractosoma lombardicum Brôlemann, 1892 (par monotypie).

Syn. :

Ornithogona Cook, 1896 (espèce-type par monotypie : Atractosoma helveticum Verhoeff, 1894).

Limnalpium Verhoeff, 1921 (espèce-type désignée par Attems, 1927 : Atractosoma helveticum Verhoeff,

1894).

Dorasoma Verhoeff, 1932 (espèce-type désignée ici : Dorasoma serratum Verhoeff, 1932).

La plupart des autres noms de genres (cités p. 459 et 460) tels Ceratosoma, Euceratosoma, Atractosoma, Ochogona,

Limnalpium et Triakontazona, qui ont pu épisodiquement abriter tel ou tel taxon de rang spécifique actuellement

rapporté au genre Bomogona , recouvrent en fait des taxons de rang générique distinct.

Bomogona lombardica (Brôlemann, 1892)

Syn. :

Atractosoma lombardicum Brôlemann, 1892

Atractosoma lombardicum (Brôl., 1892); Brôlemann, 1895

— 468 —

Bomogona lombardica (Brôl., 1892); Cook, 1895

Bomogona lombardicum (Brôl., 1892); Hoffman, 1979

Ceratosoma ( Limnalpium ) luganensis Verhoeff, 1921 (syn. nov.)

Ceratosoma (Limnalpium) luganensis ruscorum Verhoeff, 1921 (syn. nov.)

Ceratosoma (Limnalpium) luganensis (Verhoeff, 1921) ; Attems, 1927

Ceratosoma (Limnalpium) fontis Verhoeff, 1932 (syn. nov.)

Asandalum luganense luganense (Verhoeff, 1921); Attems, 1949

Asandalum luganense ruscorum (Verhoeff, 1921); Attems, 1949

Triakontazona (Limnalpium) luganense (Verhoeff, 1921) ; Strasser, 1978

Ochogona luganensis (Verhoeff, 1921); Strasser et Minelli, 1984

Ochogona luganensis (Verhoeff, 1921); Kurnik, 1986

Bomogona lombardica larii (Verhoeff, 1921)

Syn. :

Ceratosoma (Limnalpium) larii Verhoeff, 1921

Ceratosoma (Limnalpium) larii (Verhoeff, 1921); Attems, 1927

Asandalum larii (Verhoeff, 1921); Attems, 1949

Ochogona larii (Verhoeff, 1921); Strasser et Minelli, 1984

Bomogona ( Ornithogona ) helvetica (Verhoeff, 1894)

Syn. :

Atractosoma helveticum Verhoeff, 1894

Ornithogona helvetica (Verhoeff, 1894); Cook, 1895

Triakontazona helvetica (Verhoeff, 1894); Verhoeff, 1897

Atractosoma helveticum dentatum Faës, 1902

Ceratosoma (Triakontazona) verhani Verhoeff, 1910

Ceratosoma (Limnalpium) helveticum (Verhoeff, 1894); Verhoeff, 1921

Ceratosoma (Limnalpium) verbani (Verhoeff, 1910); Verhoeff, 1921 (syn. nov.)

Ceratosoma (Limnalpium) verbani (Verhoeff, 1910); Attems, 1927

Ceratosoma (Limnalpium) helveticum (Verhoeff, 1894); Attems, 1927

Dorasoma quercuum Verhoeff, 1932 (syn. nov.)

Dorasoma serratum Verhoeff, 1932 (syn. nov.)

Dorasoma helveticum (Verhoeff, 1894); Verhoeff, 1936

Asandalum quercuum (Verhoeff, 1932); Attems, 1949

Asandalum verbani (Verhoeff, 1910); Attems, 1949

Dorasoma helveticum quercuum (Verhoeff, 1932); Strasser, 1978

Ornithogona helvetica (Verhoeff, 1894); Strasser et Minelli, 1984

Ochogona verbani (Verhoeff, 1910); Strasser et Minelli, 1984

V. Chorologie

1. Bomogona lombardica

Localités déjà publiées : a) par Brôlemann (1892 et 1895) : Italie, Lombardie, Varese : Vedano-

Olona et Gavirata, 10.1887 (4 mâles, 1 femelle jeune, 3 exemplaires). Italie, Lombardie, Como : Lecco,

31.07.1892 (1 mâle jeune, 10 jeunes). Italie, Lombardie : Erba, 29.08.1891 (1 mâle, 1 mâle j., 1 exemplai¬

re). Italie, Lombardie, Varese : Val Ganna, 8.02.1888 (1 femelle j., coll. Brôlemann). — b) par Verhoeff

(1921, 1932, 1936) et Strasser (1978) : Suisse, Tessin : Melide. Italie, Lombardie : Como. Italie,

Piémont : Torre Pellice. Italie, Piémont : Ceres. Italie, Piémont : Ala di Sura. Italie, Piémont : Pinerolo.

Italie, Piémont : Barge. Italie, Piémont : Lombardore. Italie, Piémont : Torre del Colle. Italie, Emilie-

Romagne : Borgotaro.

469

Matériel inédit de A. Pedroli [les dates précises indiquent les chasses à vue, les périodes indiquent

les piégeages (Barber)] : Suisse, Tessin : Monte Generoso (1200-1600m), 5.11.1983 (5 mâles, 6 femelles).

Suisse, Tessin: Stabio (370m), 9.11.1985 (1 mâle), 14.04.1986 (1 femelle), hiver 1985-1986 (4 mâles,

11 femelles dont 2 leg. A. P. au MNHN Paris, coll. Myriapodes DA 080). Suisse, Tessin : Melide (280 m),

16.09.1984 (2 femelles), 21.04.1985 (1 mâle), hiver 1985-1986 (1 mâle). Suisse, Tessin : Mendrisio, Piona

(920 m, versant sud du Monte Generoso), automne-hiver 1988 et 1989 (5 mâles, 13 femelles leg.

Lôrtscher).

Autres matériels : Suisse, Tessin : Lugano, 16.03.1890, coll. Brôlemann (inédit!) (1 mâle, MNHN

Paris, coll. Myriapodes DA 080).

2. Bomogona lombardica larii

Localités publiées : a) par Brôlemann (1892) ( Atractosoma lombardica) : Italie, Lombardie, Como :

Monte Resegone (près Lecco), 14.08.1892 (1 femelle). — b) par Verhoeff (1921) ( Ceratosoma larii) :

Italie, Lombardie, Como : Bellano (rive orientale). Italie, Lombardie, Como : Rovinata près Lecco (rive

orientale).

3. Bomogona helvetica

Localités déjà publiées par Verhoeff (1894), Faës (1902), Verhoeff (1910, 1921, 1932, 1936),

Strasser (1978) : Suisse, Valais : Zermatt. Suisse, Valais : Stalden. Suisse, Valais : Visp. Suisse, Valais :

Ardon. Suisse, Valais : Mauvoisin. Suisse, Tessin : Bellinzona. Italie, Lombardie : Laveno (rive orientale

du lac Majeur). Italie, Aoste : Aoste. [(Italie, Piémont, Novarra : Castelleto s. Ticino) (douteux pour l’un

de nous (J.-P. M.)]. Italie, Piémont : Ivrea, Lago Sirio.

Matériel inédit de A. Pedroli (piégeages et chasses à vue) : Suisse, Tessin : Monteggio (260 m,

région de la Tresa, vers Ponte Cremenaga), automne/hiver/printemps 1984-1985 (3 mâles, 6 femelles).

Suisse, Tessin : Malpenza (270 m, région de Ponte Tresa), printemps 1984 (2 femelles). Suisse, Tessin :

Caviano, Ranzo (260 m, lac Majeur), printemps et hiver 1984 (1 mâle, 1 femelle). Suisse, Tessin : Biasca,

Loderio (354m), septembre 1980 (1 mâle, 1 femelle). Suisse, Tessin : Lucomagno, Samprou (1870m),

printemps et automne 1985 (2 mâles, 1 femelle) et 14.9/9.11.1985 (1 femelle, léguée au MNHN Paris, coll.

Myriapodes DA 140). Suisse, Tessin : Melera, Val Morobbio (1020 m, région de Bellinzona), automne/hi¬

ver/printemps 1988-1989 (61 mâles, 50 femelles, 1 j., leg. Lôrtscher). Suisse, Tessin : Prugniasco,

Negrentino (870 m, Val Blenio), automne/hiver/printemps 1988-1989 (4 mâles, 8 femelles, 1 j., leg.

Lôrtscher). Suisse, Tessin : Ludiano, Vala (940 m, Val Blenio), automne/hiver 1988-1989 (3 mâles,

5 femelles, leg. Lôrtscher). Suisse, Tessin : Largario. Brinzosca (1000 m), automne/hiver/printemps

1988-1989 (6 mâles, 15 femelles, leg. Lôrtscher). Suisse, Tessin : Meride, San Giorgio (1080m),

automne/hiver 1988 (2 mâles, 6 femelles, leg. Lôrtscher). Suisse, Tessin : Lavertezzo, Rondana (860 m,

Valle Maggia), printemps 1988 (1 mâle, leg. P. Pronini). Suisse, Tessin : Biasca, Val Pontirone (840-

1340 m), printemps et automne 1988 (4 mâles, 5 femelles, leg. P. Pronini). Suisse, Tessin: Bodio,

22.4/7.6.1984 (1 femelle MNHN Paris, coll. Myriapodes DA 140). Suisse, Grisons : Leggia (320 m, région

de la Moesa), 28.9.1989 (1 mâle). Suisse, Valais : Champex (1466 m, bord du Lac), 26.9.1987 (2 mâles).

Suisse, Valais : Val des Dix, Le Chargeur (2100 m), 21.9.1987 (1 mâle).

Autres matériels : Suisse, Tessin : 1km au nord d’Acquarossa, 5.11.1982, coll. & leg. D. Kime

(1 mâle, MNHN Paris, coll. Myriapodes DA 140). Italie, Lombardie : Novarra, Pella (Lago d’Orta),

mars 1971, coll. Rosa (1 mâle, Museo Scienze Naturale, Bergamo). Italie, Lombardie : Santa Catarina del

Sasso (rive orientale du lac Majeur), 14.10.1888, coll. Brôlemann (inédit!) (1 mâle, MNHN Paris, coll.

Myriapodes DA 140).

Conclusion — Discussion

L’analyse de la distribution géographique, illustrée par la carte (fig. 19), montre que

Bomogona helvetica a une aire de répartition en position plus externe (et septentrionale) dans

- 470 —

l’arc alpin que Bomogona lombardica. Ceci est en harmonie avec le gradient altitudinal des

deux espèces; car en effet si toutes deux se rencontrent dès 260m d’altitude, la première

parvient à 2600 m, tandis que la seconde ne dépasse pas 1600.

En Suisse, lombardica ne se trouve que dans l’extrême sud du Tessin, dans la région du

Monte Generoso, réputé être un massif-refuge, et dans la plaine avoisinante. Dans cette

région, la distribution des deux espèces est continue, et il n’y a pas de chevauchement de leurs

aires de distribution. Un phénomène semblable a pu être observé chez d’autres Diplopodes;

ainsi dans le nord des Alpes et dans le Jura suisse il a été observé sur deux taxons du genre

Rhymogona, R. montivaga et R. cervina ; ces deux espèces parapatriques présentent cependant

une zone de contact de quelques centaines de mètres à 5 km de large, où se rencontrent des

hybrides, ce qui peut faire douter de leur statut d’espèces (Pedroli-Christen & Scholl, 1990

— 471 -

et 1991). Chez Bomogona, on n’a encore rien observé de semblable, mais le phénomène n’est

pas à exclure, tant que l’on n’aura pas prospecté minutieusement certaines zones : par exemple

celle qui sépare les massifs-refuges du Monte Generoso et du Monte San Giorgio, qui sont

occupés respectivement par B. lombardica et B. helve tica et dont les flancs ne sont séparés que

par de faibles distances (1-2 km).

D’autre part, il est assez frappant de constater, à l’examen de la carte, que si B. Helvetica

présente une aire relativement petite avec chorologie relativement homogène, il n’en est pas de

même de B. lombardica. La chorologie discontinue de cette dernière, qui ne peut s’expliquer

entièrement par des défauts de recensement (en trois aires : une aire tessino-lombarde, une aire

piémontaise et un isolat nord-apennin), est typique d’une espèce en régression ayant eu

autrefois une aire plus vaste; le fait (à confirmer) que ses deux aires principales (tessino-

lombarde et piémontaise) sont séparées par une large zone qui est occupée, au moins

partiellement, par helveticum, tendrait au contraire à nous laisser penser que, à la différence de

ce qui se passe chez Rhymogona, Bomogona helveticum aurait tendance à supplanter

lombardicum plutôt qu’à produire des hybrides avec elle.

Remerciements

Nous tenons à remercier le Dr. G. Cotti, du Museo di Storia Naturale di Lugano, Paola Pronini

(Lugano) et Matthias Lôrtscher (Berne) pour leur collaboration dans le piégeage du matériel étudié,

ainsi que le Dr. H. Fechter, qui a mis à notre disposition le matériel de référence déposé au Zoologische

Staatsammlung de Munich, et M”' Michèle Bertoncini (Paris), auteur des illustrations de cette note.

Dans ce travail est intégrée une partie des résultats de la thèse de doctorat de A. Pedroli-Christen

soutenue le 6 novembre 1992 à l’Institut de Zoologie, Université de Neuchâtel, Suisse.

AUTEURS CITÉS

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— 1949. — Die Myriopodenfauna der Ostalpen. Sitz. ber. ôsterr. Akad. Wiss., Wien, 158 (1-2) : 79-

153.

Brôlemann, H. W., 1892. Contributions à la Faune Myriapodologique méditerranéenne : deux

espèces nouvelles. Ann. Soc. linn. Lyon, 39 : 7-40.

1895. — Elenco di Miriapodi raccolti in Lombardia. Atti Soc. ital. Sci. nat., Milano, 23 : 1-34.

Cook, O. F., 1895. In Cook & Collins, Introductory note on the families of Diplopoda. The

Craspedosomatidae of North America. Ann. N. Y. Acad. Sci., 9 : 1-75.

— 1896. — On recent Diplopod names. Brandtia, New York 3 : 5-8.

Faës, 1902. — Myriapodes du Valais. Revue suisse Zool., Genève, 10 : 31-165.

Hoffman. R. L., 1979. — Classification of the Diplopoda. Ed. Muséum d’His. Nat., Genève : 1-238.

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der Weibchen. Diss. Dokt. Naturw. Fak. Univ. Innsbruck, 1986.

Pedroli-Christen, A., & A. Scholl, 1990. Ecological and genetic studies on parapatric Rhymogona

silvatica Roth, and R. cervina Verh. (Diplopoda : Craspedosomatidae) with special reference to

hybrid populations in a zone of contact. Revue suisse Zool., Genève, 97 (2) : 349-359.

- 472 -

Pedroli-Christan, A., & A., Scholl, 1991. — Systématique et taxonomie du genre Rhymogona

(Diplopoda Craspedosomatidae) : Rhymogona silvatica (Rothenbühler, 1899) synonyme de

Rhvmogona montivaga (Verhoeff, 1894); résultats morphologiques et génétiques. Revue suisse

Zool. , Genève, 98 (1) ; 83-92.

Strasser, K., 1978. Diplopodi del Piemonte. Boll. Mus. Civ. Slor. nat. Verona , 5 : 141-173.

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212 .

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296.

— 1897. — Beitrâge zur Kenntniss palâarktischer Myriapoden V. Aufs. : Uebersicht der mir genauer

bekannten europàischen Chordeumiden-Gattungen. Arch. Naturgesch., 63 (1, 2) : 129-138.

— 1899. — Beitrâge zur Kenntniss palâarktischer Myriapoden VIII. Aufs. : Zur vergleichenden

Morphologie, Phylogénie, Gruppen- und Artsystematik der Chordeumiden. Arch. Naturgesch., 63

(1, 2) : 95-154.

— 1910. — Über Diplopoden. 11.-15.Aufsatz (31.-35) : Beitrâge zur Kenntnis der Glomeriden,

Juliden, Ascospermophora und Lysiopetaliden, sowie zur Fauna Siziliens, etc... Nova Acta, Halle,

92 (2) : 139-448.

— 1921. — Über Diplopoden der Riviera und einige alpenlàndische Chilognathen (92. Diplopoden-

Aufs.). Arch. Naturgesch., 87, A, (2): 1-110.

— 1932. — Zur Géographie, Okologie und Systematik der Diplopoden Nordwestitalien (123.

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(132. Aufsatz). Zool. Jb., (Syst.), Iena, 68 (2/3) : 205-272.

19366. — Chilognathen aus Nordwestitalien und über einige andere mediterrane Diplopoden

(128. Aufsatz). Zool. Jb., (Syst.), Iena, 68 (4/5) : 353-444.

Bull. Mus. nail. Hist, nat., Paris, 4 e sér., 14, 1992,

section A, n° 2 : 473-481.

Biogéographie des espèces

du groupe naturel « Tityus clathratus »

(Chelicerata, Scorpiones, Buthidae)

par Wilson R. Lourenço

Résumé. Une nouvelle synthèse biogéographique est proposée pour les onze espèces associées au

groupe naturel de Scorpions défini en tant que « Tityus clathratus ». Les modèles actuels de distribution et

de différenciation sont discutés à partir de considérations fondées sur des facteurs historiques et

écologiques.

Abstract. — A new biogeographic synthesis is proposed to the eleven species associated to the

natural group of scorpions defined as ‘Tityus clathratus ’. The present patterns of distribution and

differentiation are discussed taking in consideration the influence of historical and ecological factors.

W. R. Lourenço, Université Pierre et Marie Curie, UFR des Sciences de la Vie, 4, pi. Jussieu, F-75252 Paris

cedex 05.

Introduction

Le genre Tityus (famille des Buthidae) est celui qui présente la plus importante richesse

spécifique parmi les genres mondiaux de Scorpions; plus d’une centaine d'espèces sont

répertoriées. Le seul travail monographique qui ait traité de la totalité des espèces connues, à

l’époque de sa rédaction, est celui de Mello-LeitÂo (1945). Ce travail est cependant très

désactualisé tant sur le plan de la nomenclature que sur le plan du concept de l’espèce et ne

présente plus guère qu’un intérêt historique.

Face à la très grande difficulté présentée par le genre Tityus pour toute étude globale

concernant sa phylogénie et sa biogéographie, plusieurs auteurs ont entrepris des études

partielles sur un nombre limité d’espèces du genre, soit par régions géographiques (Maury,

1979; Gonzalez-Sponga, 1984), soit en partant de la définition de groupes naturels d’espèces

à l’intérieur du genre (Lourenço, 1984a, b, 1987a; Lourenço et Eickstedt, 1987).

A présent, on constate qu’aucune de ces approches ne semble satisfaisante, en l’absence

d’une réelle analyse portant sur la totalité des éléments d’un groupe naturel donné, associée à

des études sur les milieux naturels dans lesquels ils habitent.

Une analyse globale du genre Tityus a été entreprise par nos soins depuis une quinzaine

d’années; non encore terminée, elle se fonde sur des bases évolutives, écologiques et

biogéographiques. Ainsi, l’approche présentée ici n’est qu’une partie de ce travail en

préparation, qui porte sur un groupe naturel désormais bien défini : le groupe naturel

- 474 -

d'espèces « Tityus clathratus ». Ce groupe a déjà fait l’objet d’une étude partielle par

Lourenço (1984a). Depuis, d’autres espèces appartenant à ce groupe ont été décrites

(Francke et Stockwell, 1987; Lourenço, 1991), et une nouvelle espèce se rattachant à ce

groupe est décrite dans la présente note.

Tityus betschi n. sp.

(Fig. 1 à 4)

Matériel-type : Holotype femelle : Colombie, Depto. Valle del Cauca ; Parque Nacional Farallones

de Cali (Cerca a Pance, 1450m ait., en techo de un rancho rural), IX, 1988, leg. E. Florez. Muséum

national d’Histoire naturelle, Paris, MNHN-RS-8552.

Étymologie : Le nom spécifique est créé en hommage à notre collègue le Dr. Jean-Marie Betsch du

Muséum national d’Histoire naturelle, Paris.

Description

Coloration générale jaunâtre avec des taches châtain brunâtre. Prosoma jaunâtre avec des

taches brunâtres diffuses; tubercule oculaire et yeux latéraux noirâtres. Mesosoma : tergites I

Fig. 1 à 4. - Tityus betschi, holotype $ : 1, pince, vue externe; 2, tibia, vue dorsale; 3, chélicère; 4, V e anneau du

métasoma et telson, vue latérale.

— 475 —

à VII avec le même dessin que la plaque prosomienne. Sternites jaune brunâtre avec des taches

diffuses dans la région postérieure de chaque sternite. Metasoma : anneaux caudaux I à V

jaunâtres, avec des taches brunâtres plus diffuses que celles du prosoma et du mesosoma.

Telson jaune rougeâtre avec des taches très estompées. Peignes, opercule génital, sternum,

hanches et processus maxillaires ocre-jaune. Pattes et pédipalpes jaunâtres, avec des taches

brunâtres diffuses. Chélicères jaunâtres avec des taches noires dans sa partie antérieure.

Prosoma : front de la plaque prosomienne avec une échancrure frontale moyennement

marquée. Tubercule oculaire antérieur par rapport au centre de la plaque prosomienne ; yeux

médians séparés par plus d’un diamètre oculaire; trois paires d’yeux latéraux. Plaque

prosomienne faiblement granulée ; carènes médianes oculaires allant du bord antérieur

jusqu’en arrière du tubercule oculaire ; carènes médianes postérieures moyennement marquées ;

sillon interoculaire bien marqué.

Mesosoma : tergites moyennement granulés ; carène axiale présente sur tous les tergites ;

tergite VII avec cinq carènes, l’axiale limitée au tiers antérieur ; les deux médianes et les deux

latérales fusionnées dans la région proximale. Sternites très peu granulés ; stigmates linéaires.

Peignes avec 13-13 dents; lame basilaire intermédiaire non dilatée.

Metasoma : anneau I avec 10 carènes; anneaux II à IV avec 8 carènes; anneau V avec 5

carènes ; espaces intercarénaux faiblement ou moyennement granulés ; vésicule peu granulée ;

épine sous-aiguillonnaire rhomboïdale et importante, avec deux granules ventraux.

Pédipalpes : fémur à 5 carènes, tibia à 7 carènes, la carène interne-dorsale à granules

spiniformes. Pince avec 9 carènes. Tranchant des doigts mobiles avec 14-14 séries de granules.

Chélicères avec la dentition comme chez d’autres Tityus. Trichobothriotaxie : A-Alpha,

orthobothriotaxique.

Mensurations (en mm) de l’exemplaire décrit : Prosoma, longueur 4,2 ; largeur antérieure 2,9. Anneau

caudal I, longueur 2,6; largeur 2,1. Anneau caudal V, longueur 5,2; largeur 1,7; hauteur 1,8. Vésicule,

largeur 1,6; hauteur 1,5. Pince, largeur 1,6; hauteur 1,4. Doigt mobile, longueur 5,3.

Biogéographie des espèces du groupe naturel « Tityus clathratus »

Au total onze espèces peuvent être incluses dans le groupe naturel « Tityus clathratus ».

Elles sont réparties en trois sous-groupes selon leurs affinités phylogénétiques et selon leurs

« patterns » de distribution géographique.

Premier sous-groupe ;

— Tityus paraguayensis Kraepelin, habitant du chaco, formation végétale ouverte semi-

xérophytique de la région méridionale de l’Amérique du Sud (Lourenço, 1990) ;

— Tityus mattogrossensis Borelli, espèce des cerrados du centre du Brésil (Lourenço,

1979).

Deuxième sous-groupe :

Tityus pusillus Pocock, endémique de la région nord de la forêt atlantique du Brésil,

dans l’État de Pernambuco (Lourenço, 1982);

— Tityus silvestris Pocock et Tityus bastosi Lourenço, deux espèces à distribution

fondamentalement amazonienne ; la première est répartie sur l’ensemble de l’Amazonie, avec

une légère pénétration sur la région guyanaise (Lourenço, 1988a); la deuxième est présente

sur la région occidentale de l’Amazonie (Lourenço, 1984a);

— Tityus clathratus Koch, à distribution typiquement guyanaise qui déborde légèrement

sur les îles continentales du Vénézuela, et Tityus atriventer Pocock, endémique de l’île de

Grenade (Lourenço, 1984c); ces deux espèces sont des vicariantes.

Troisième sous-groupe :

— Tityus columbianus (Thorell) et Tityus betschi n. sp., deux espèces vicariantes; elles

habitent respectivement des savanes d’altitude et des forêts sèches de semi-altitude en

Colombie ;

— Tityus tayrona Lourenço et Tityus ocelote Stockwell et Francke; la première espèce

habite les forêts humides de Santa Marta en Colombie (Lourenço, 1991); la deuxième est

connue des forêts humides du Costa Rica.

Il va de soi que le présent inventaire des espèces du groupe naturel « Tityus clathratus » ne

peut encore être considéré comme définitif.

Au vu de la très grande homogénéité morphologique des espèces du groupe, une analyse

phylogénétique précise s’avère très difficile; la caractérisation des apomorphies et des

plésiomorphies apparaît comme peu réalisable à partir des seuls caractères morphologiques

généraux. De ce fait, la définition des sous-groupes est également fondée sur d’autres

caractères que ceux tirés de la morphologie, avec une tentative d’optimisation des données

écologiques et biogéographiques (tabl. I).

Les « patterns » actuels de répartition et de différenciation

des espèces du groupe « Tityus clathratus »

La figure 5 représente la répartition actuelle connue des onze espèces associées au groupe

« T. clathratus ». L’évolution même des aires de répartition des diverses espèces est

conséquence à la fois des facteurs historiques responsables de l’évolution de la région mais

aussi des stratégies adaptatives (facteurs écologiques) spécifiques de chacune des espèces

(tabl. I).

Les Scorpions correspondent en général à des souches génétiques anciennes; ainsi, on

peut estimer que le groupe « T. clathratus » correspond à une lignée existant déjà depuis le

Tertiaire supérieur au moins (Schwaller, 1982).

Comme tous les Tityus, ceux du groupe « T. clathratus » ont leur centre d’origine en

Amérique du Sud ; cependant, on ne peut encore affirmer lequel des deux boucliers, guyanais

ou brésilien (Haffer, 1981), a été le foyer d’origine du groupe au cours du Tertiaire.

— 478 —

Tableau I. — Caractéristiques écologiques et biologiques des espèces du groupe « T. clathratus ».

Espèce

Habitat

Micro-habitat

Morphologie

Biologie reproductrice

T. mattogros-

cerrado

s/termitières, bois.

monomorphe

sexuée

sensis

pierres; dans pal-

miers

T. paraguayen-

sis

chaco

s/bois

monomorphe

sexuée

T. pusillus

forêt humide

s/pierres; litière

monomorphe

sexuée

T. silvestris

forêt humide

dans litière et pal-

polymorphe ;

sexuée

miers

ochlospecies

T. bastosi

forêt humide

dans litière

polymorphe ;

ochlospecies

sexuée

T. clathratus

forêt humide

dans litière ; s/bois

polymorphe ;

sexuée

et sèche

cline

T. atriventer

forêt humide

dans litière; s/bois

monomorphe

sexuée

T. tayrona

forêt humide

dans litière; s/bois

monomorphe

sexuée

T. ocelote

forêt humide

dans litière

monomorphe

sexuée

T. columbianus

savane d’alti-

s/pierres

monomorphe

sexuée et partheno-

tude

génétique

T. betschi

forêt sèche

s/bois

monomorphe

sexuée

Les parentés phylogénétiques sont en général corrélées avec les distributions géographi¬

ques, voire avec certains traits de l’écologie des espèces (tabl. I). Les aspects suivants peuvent

être mis en évidence :

— Tityus mattogrossensis et Tityus paraguayensis sont des espèces habitant exclusivement

des formations végétales ouvertes du type savanicole, dans les régions centrale et méridionale

d’Amérique du Sud.

- Tityus pusillus, endémique de la région nord de la forêt atlantique, a dû s’isoler des

espèces amazoniennes par suite de la disparition des ponts entre les deux forêts humides

(Andrade-Lima, 1982; Lourenço, 1988b).

— Tityus clathratus , espèce adaptée aux forêts humides dans la région guyanaise, affiche

une répartition disjointe; les populations que l’on retrouve au nord du Vénézuela et sur ses îles

continentales habitent des milieux forestiers beaucoup plus secs (fig. 5).

— Tityus atriventer, espèce vicariante de T. clathratus, est le résultat d’une dispersion du

groupe vers les Antilles avec différenciation postérieure due à son isolement dans l’île de

Grenade. Cette dispersion a probablement eu lieu au cours des très importantes glaciations du

Quaternaire ; pendant cette période, le niveau des mers a connu de très importantes réductions,

de l’ordre de 100 à 150 m (Lourenço, 1987b) ; de ce fait, la distance entre l’Amérique du Sud et

l’île de Grenade fut réduite de 125 km à environ 30 km, du fait de l’émersion des bancs

(Griffiths et Klingener, 1988).

— Tityus silvestris et Tityus bastosi sont des espèces à large répartition sur l’Amazonie ;

elles affichent toutes les deux un polymorphisme du type ochlospecies (Lourenço, 1988). Cette

variabilité génétique, exprimée morphologiquement, met en évidence, lorsqu’elle est corrélée

avec les « patterns » de distribution, des caractéristiques d’une colonisation « récente » du

bassin amazonien, qui a dû se réaliser progressivement à la suite de la réexpansion de la forêt

— 479 —

humide après l'événement du dernier épisode sec. En outre, si l’hypothèse de l'existence d'un

grand lac sur le bassin amazonien dans des périodes récentes est retenue (cf. Lago Amazonas),

la colonisation de cette région par les deux espèces ne peut être datée que postérieurement à la

disparition du lac en question (Frailey et al., 1988; Mori, 1991).

— Tityus columbianus et T. betschi habitent dans des milieux secs respectivement

savanicoles et forestiers dans les cordillères occidentale et orientale de Colombie.

— Tityus tayrona et Tityus ocelote habitent des milieux du type forêt humide. La

première espèce aurait pu se différencier dans le centre d’endémisme Santa Marta en Colombie

(Lourenço, 1991), tandis que la deuxième a pu subir sa différenciation au Costa Rica en

Amérique centrale, par suite de la dispersion et de la colonisation de cette région par des

éléments du groupe en association avec des périodes d’isolement.

80 70 60 50 40

— 480 —

Conclusions

Si Tityus mattogrossensis et Tityus paraguayensis sont des espèces adaptées à des

formations végétales ouvertes, partiellement xérophytiques, elles sont néanmoins séparées par

une barrière représentée par le « Pantanal » du Mato Grosso, zone beaucoup plus humide et

inondée annuellement; cette barrière écologique est ainsi très efficace.

Tityus pusillus est endémique de la forêt atlantique située sur la région côtière de l'État de

Pernambuco au Brésil. La très vaste dégradation de cette forêt impose un net recul des

populations animales jusqu’à leur totale disparition (Prance et Campbell, 1988). Cette espèce

très menacée d’une disparition totale a dû avoir jadis une répartition plus importante.

La distribution disjointe de Tityus clathratus pourrait être expliquée à partir de la théorie

du « Lago Amazonas » qui aurait existé à la fin du Pléistocène et au début de l’Holocène

(fig. 6). En fait, l’étendue de ce lac, proposée par Frailey et ai (1988), recouvre bien la zone

de disjonction dans la distribution actuelle de T. clathratus.

En se fondant également sur l’hypothèse du « Lago Amazonas », il est possible de

postuler que les répartitions actuelles de Tityus silvestris et de Tityus bastosi sont les plus

récemment établies, parmi celles des espèces du groupe « T. clathratus » ; elles sont très

probablement encore en voie d’expansion. La condition d’ochlospecies est en général en

corrélation avec les caractéristiques d’une différenciation et d’une distribution récentes

(Prance, 1982; Lourenço, 1988a).

Les différenciations de Tityus tayrona, Tityus columbianus et de Tityus betschi semblent

être associées à des refuges quaternaires qui se sont retrouvés isolés à plusieurs reprises au

cours de l’alternance des épisodes secs et humides (Lourenço, 1986; Lourenço et Florez,

1990).

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cene lake in the amazon basin and its significance to amazonian geology and biogeography. Acta

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— 481 —

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section A, n° 2 : 483-500.

Présence du genre Bathynarius (Crustacea, Decapoda, Diogenidae)

en Indonésie et dans le Pacifique central,

avec la description de deux espèces nouvelles

par Jacques Forest

Résumé. — Le genre d’eau profonde Bathynarius, récemment établi avec deux espèces incluses,

s’agrandit avec la description de B. wolffi et B. pacificus spp. nov. Sa distribution géographique, jusqu’à

présent restreinte à la mer des Antilles et à l’océan Indien, se trouve étendue à l’Indonésie et à la Polynésie.

La capture dans cette dernière région de plusieurs spécimens de l’espèce de l’océan Indien, B. albicinctus

(Alcock), a permis de compléter la comparaison avec B. anomalus (A. Milne Edwards et Bouvier).

Diagnose et définition ont été amendées en fonction des particularités des nouveaux taxa et une clef

d’identification est fournie pour les quatre espèces.

Abstract. — The deep sea genus Bathynarius, recently established with two included species, is

enlarged by the description of two further species, B. wolffi and B. pacificus spp.nov. Its geographical

distribution, until now restricted to the Caribbean Sea and Indian Ocean, is extended to Indonesia and

Polynesia. The capture in this last area of several specimens of the Indian species, B. albicinctus (Alcock),

enables a full comparison with the Western Atlantic species B. anomalus (A. Milne Edwards et Bouvier).

The diagnosis and definition of the genus are amended in accordance with the particularities of the new

taxa and an identification key is provided for the four species.

J. Forest, Laboratoire de Zoologie (Arthropodes) , Muséum national d’Histoire naturelle, 61 rue Buffon, 75005 Paris.

Le genre Bathynarius a été récemment établi (Forest, 1989 : 759) pour deux espèces

précédemment rangées dans le genre Clibanarius Dana. La première, B. anomalus ( A. Milne

Edwards et Bouvier, 1893), vit dans les parages des Petites et Grandes Antilles, alors que la

seconde, B. albicinctus (Alcock, 1905), décrite du sud de l’Inde, n’avait été retrouvée qu’au

large de l’île de La Réunion. Étroitement apparentées, en dépit de leur éloignement

géographique, les deux espèces se distinguent par une coloration fort différente.

Les Bathynarius et les Clibanarius ont en commun un habitus assez voisin, ce qui explique

les confusions antérieures, mais sont en fait sans affinités réelles. Ils ont aussi une distribution

tout à fait différente : les premiers vivent en eau profonde, alors que les Clibanarius se tiennent

dans la zone intertidale ou à proximité.

Le genre Bathynarius s’enrichit aujourd’hui de deux nouvelles espèces et en même temps

sa distribution géographique s’élargit considérablement. Il est en effet représenté parmi les

nombreux et intéressants crustacés recueillis par J. Poupin en Polynésie française, dans le cadre

des activités du Service Mixte de Contrôle Biologique des Armées. Il s’agit d’abord d’un

échantillon de onze spécimens capturés en même temps dans des nasses aux îles Marquises, par

— 484

210 m de profondeur. L’un de ces spécimens est indiscutablement identifiable à B. albicinctus

qui, nous l’avons dit, n’était connu que de deux localités de l’océan Indien, alors que les dix

autres appartiennent à une nouvelle espèce décrite ici sous le nom de B. pacificus sp. nov. Un

second échantillon, provenant celui-là des îles Tubuaï, comprend seize B. albicinctus, et un

spécimen unique recueilli aux Tuamotu appartient à la même espèce. Enfin, les pagures du

Zoologiske Museum de Copenhague, qui m’ont été confiés par le Dr. Torben Wolff, incluent

également un spécimen d’un autre Bathynarius nouveau provenant des récoltes du Dr. Th.

Mortensen aux îles Kei : B. wolffi sp. nov.

La présente note comporte la description des deux nouvelles espèces et des remarques sur

leurs affinités et leur distribution, ainsi que des données complémentaires sur B. albicinctus,

grâce à l’examen d’un assez grand nombre d’exemplaires. Mes observations précédentes sur

l’espèce d’ALCOCK portaient essentiellement sur un spécimen unique (Forest, 1989 : 770). En

le comparant aux nombreux B. anomalus disponibles, j’avais noté de minimes différences dont

la signification spécifique restait douteuse, dans l’ignorance des variations morphologiques

possibles d 'albicinctus. Le nouveau matériel obtenu confirme que les deux espèces sont proches,

tout en se distinguant non seulement par la coloration, mais aussi par une série de caractères

principalement liés à l’ornementation.

Des remarques complémentaires sont également présentées sur les caractères du genre

Bathynarius. En effet, si les deux espèces décrites ici offrent les principaux traits morphologi¬

ques auxquels avait été accordée une signification générique, certaines de leurs particularités

ont montré que définition et diagnose nécessitaient quelques corrections.

Chaque fois que la taille d’un spécimen est précisée, il s’agit de la longueur de l’écusson

céphalothoracique sur son axe médian. En effet, la longueur de la carapace entre le sommet du

rostre et soit l’échancrure médiane (comme dans mes précédentes publications), soit le bord des

lobes branchiaux, est sujette à de fortes fluctuations pour un écusson de longueur donnée, en

raison de la nature membraneuse et de l’absence de rigidité des téguments au niveau de la partie

postérieure du céphalothorax.

Bathynarius albicinctus (Alcock, 1905)

(Fig. 2, 7, 10)

Clibanarius albicinctus Alcock, 1905 : 50, pl. 4, fig. 4 ; Buitendijk, 1937 : 267 ; Forest, 1952 : 34 ; Fize

et Serène, 1955 : 69, 70, 74.

Bathynarius albicinctus-. Forest, 1989 : 768, fig. 2, 3, 6.

Matériel examiné. — Iles Marquises, Fatuhiva, Récoltes du Service Mixte de Contrôle Biologique

des Armées, station 303, 10°31,4'S, 138°39,2'W, 210 m, nasses, J. Poupin coll. 03.09.1990 : 1 $ 5,5 mm

(Pg 4864). — Archipel des Tuamotu, Fangataufa, Récoltes du Service Mixte de Contrôle Biologique des

Armées, station 322, 22°12,9'S, 138°43,1'W, 250 m, nasses, J. Poupin coll., 23.10.1990 : 1 $ 5,4 mm (Pg

4865). — Iles Tubuaï, Rurutu, Récoltes du Service Mixte de Contrôle Biologique des Armées, station 337,

22°28,6'S, 151°21,8'W, 125 m, nasses, J. Poupin coll., 27.11.1990 : 10 d 4,5 à 8,7 mm, 6 ? 5,2 à 7,2 mm,

dont 2 ovigères de 5,4 mm et 7,2 mm (Pg 4866).

— 485 —

Remarques

Les dix-huit exemplaires de Bathynarius des îles Marquises, Tuamotu et Tubuaï

mentionnés ci-dessus sont incontestablement identifiables à B. albicinctus (Alcock). Ils

correspondent à la description originale et présentent les caractéristiques du spécimen de La

Réunion étudié lors de l’établissement du genre (Forest, 1989 : 768), avec en particulier une

coloration tout à fait identique. L’examen de ce nouveau matériel donne une idée des variations

de l’espèce et permet de préciser ses rapports avec celle des Antilles, B. anomalus (A. Milne

Edwards et Bouvier). Les deux espèces se distinguent immédiatement par la pigmentation. Les

péréiopodes de B. albicinctus sont d’un rouge intense piqueté de blanc — teinte à peine atténuée

huit ans après la fixation — et marqués de larges anneaux blancs, alors que, chez B. anomalus,

ces appendices sont d’une teinte rose assez uniforme et fugace.

Les dimensions relatives des pédoncules oculaires, antennulaires et antennaires, sont

sensiblement les mêmes chez l’une et chez l’autre, avec des variations d’une même étendue. Le

rapport de la longueur des pédoncules oculaires à celle de l’écusson a été calculé chez tous les

B. albicinctus, qui mesurent de 4,0 à 8,7 mm : il s’échelonne entre 3/4 et 4/5. Quant à l’indice

cornéen, c’est-à-dire le rapport de la longueur des pédoncules au diamètre des cornées, il est

compris entre 4,3 et 5,4. Ces rapports, indépendants du sexe, apparaissent dans l’ensemble

comme liés à la taille : les individus les plus grands ont des pédoncules oculaires relativement

plus longs et plus grêles, avec des cornées plus petites. Les mesures effectuées chez B. anomalus

avaient donné des résultats similaires, avec des variations d’une plus grande amplitude,

conséquence de l’examen d’un nombre beaucoup plus élevé d’individus et d’un plus large

échelonnement des tailles. En ce qui concerne la forme des pédoncules oculaires, on peut

déceler un très léger renflement de la région cornéenne, fréquent chez albicinctus, plus rare chez

anomalus.

La différence, déjà relevée, dans la spinulation des écailles antennaires se trouve

confirmée : les dents épineuses, la distale comprise, sont plus longues, plus fines et plus aiguës

chez albicinctus.

Les chélipèdes offrent des particularités spécifiques, non seulement dans leur ornementa¬

tion, mais aussi dans la forme et les proportions de la main. Chez albicinctus (fig. 2), celle-ci

est modérément renflée du côté ventral, le bord latéral présente une convexité légèrement

atténuée vers son milieu et la région digitale est de forme ovalo-triangulaire ; la main est près

de deux fois plus longue que large et la région digitale occupe les 4/7 e de la longueur totale.

Chez anomalus (fig. 3), la main présente un renflement latéro-ventral marqué, le bord latéral

est convexe au niveau de la paume, puis droit ou même légèrement concave, puis faiblement

convexe jusqu’à l’ongle ; la région digitale est nettement triangulaire ; la largeur de la main est

sensiblement égale aux 3/5e de la longueur totale et les doigts, plus longs, occupent les 3/5e de

cette longueur. La face dorsale de la main de B. anomalus est couverte de forts tubercules

coniques, à sommet le plus souvent corné , aigu ou émoussé. Chez B. albicinctus, les tubercules

sont un peu plus nombreux mais de taille irrégulière, les plus grands nettement plus petits que

chez anomalus, et en cônes plus aigus.

Les longueurs relatives des articles des deuxièmes et troisièmes péréiopodes sont à peu près

les mêmes chez les deux espèces, avec des variations notables chez l’une et chez l’autre. Ces

articles sont cependant nettement plus allongés, plus grêles chez B. albicinctus (fig. 7) que chez

B. anomalus (fig. 6) : ainsi, les rapports de la longueur du propode à sa hauteur maximale pour

— 486 —

les deuxièmes et troisièmes péréiopodes gauches (article toujours nettement plus court sur le

second de ces appendices) sont-ils en moyenne respectivement égaux à 3,4 et 3,0 chez

albicinctus, à 2,7 et 2,4 chez anomalus. En outre, la région distale du dactyle est plus fortement

recourbée et l’ongle relativement plus long chez albicinctus. On observe aussi de fortes

variations individuelles dans le développement des denticules cornés sur la région dorsale du

carpe, du propode et du dactyle des pattes ambulatoires. Cependant ces denticules sont dans

l’ensemble moins forts, avec une base calcifiée souvent réduite et une épine apicale plus fine,

chez B. albicinctus, où ils sont parfois à peine discernables.

Les deux espèces ont un sixième tergite abdominal à bord postérieur garni de

denticulations irrégulières et en nombre variable (fig. 10 et 11). Elles ont l’une et l’autre un

telson fortement asymétrique et de forme voisine, mais nettement plus long que large chez B.

albicinctus, alors que les deux dimensions sont subégales chez B. anomalus. Chez le premier, le

lobe gauche est très allongé, ses bords ne convergent que faiblement avant de se rejoindre en

un parfait arrondi ; chez le second ce lobe est plus court et aussi plus triangulaire. Quant au

lobe droit, toujours très arrondi, il est plus court et moins saillant encore chez B. albicinctus

que chez B. anomalus.

B. albicinctus, qui n’était connu que de l’océan Indien — sud de l’Inde et île de La Réunion

— voit sa distribution géographique étendue, de façon considérable, à la Polynésie française.

A en juger par le nombre d’individus recueillis en une seule station, il est probable qu’elle n’est

pas rare dans cette région et qu’elle sera retrouvée ailleurs dans le Pacifique.

C’est à 125 m de profondeur, aux Tubuaï, qu’ont été obtenus les échantillons les plus

nombreux, alors que les autres récoltes, avec un ou deux exemplaires seulement, aux

Marquises, aux Tuamotu et dans l’océan Indien, ont été faites entre 185 et 250 m.

Bathynarius pacificus sp. nov.

(Fig. 1, 4, 9, 12)

Matériel examiné. — Iles Marquises, Fatuhiva, Récoltes du Service Mixte de Contrôle Biologique

des Armées, station 303, 10°31,4'S, 138°39,2'W, 210 m, nasses, J. Poupin coll. 03.09.1990 : 8 8,1 à

11 mm, 2 $ 5 et 6,1 mm.

Type. — Un mâle de 10,5 mm a été désigné comme holotype (MNHN Pg 4867). Les neuf autres

spécimens sont des paratypes (Pg 4868).

Localité-type. — Voir ci-dessus.

Coquilles. — Bursa latitudo wolfei Ben, Conus monachus L., Morum sp.nov.

Description

Ecusson céphalothoracique (fig. 1) en général nettement plus long que large. Bords

latéraux faiblement convexes, avec une indentation peu prononcée en arrière de leur milieu.

Rostre en triangle très obtus, à sommet émoussé dépassant les saillies postantennaires qui

portent un très petit denticule. Surface de l’écusson marquée de dépressions lui donnant un

Fig. 1. — Bathynarius pacifiais sp. nov., SMCB, st. 303 (I. Marquises), mâle holotype 10,5 mm. Région antérieure de

la carapace et appendices sensoriels ( x 5,5).

aspect corrodé, sauf sur la région gastrique qui est presque lisse. Sur la moitié postérieure de

l’écusson deux sillons régulièrement arqués, décalcifiés, convergent vers l’arrière et peuvent se

prolonger jusqu’au sillon cervical en une courte ligne médiane. Sur la moitié antérieure, en

arrière du rostre les dépressions coalescentes forment une gouttière médiane qui se prolonge

par une ligne très fine ; celle-ci, vers le tiers de la longueur de l’écusson, diverge en un Y dont

les branches rejoignent ou non les sillons arqués de la moitié postérieure. Ces sillons en Y sont

Fig. 2-5 . — Main du chélipède gauche, vue dorsale : 2, Bathynarius albicinctus (Alcock), « Marion-Dufresne », camp.

MD 32, st. CP 57 (I. de La Réunion), femelle 7,5 mm ; 3, B. anomalus (A. Milne Edwards et Bouvier), « Gerda »,

st. 251 (Floride), mâle 7,6 mm ; 4, B. pacificus sp. nov., SMCB, st. 303 (1. Marquises), mâle paratype 9,5 mm ; 5,

B.wolffi sp. nov., The Danish Expedition to the Kei Islands 1922, st. 3, mâle holotype 5,7 mm.

— 489 —

diversement développés ; ils peuvent être, au moins partiellement, marqués par une ligne

décalcifiée ou être atténués, mais sont toujours discernables. Un fin sillon traverse la partie

antérieure de la région cardiaque.

Pédoncules oculaires égaux ou un peu plus longs à gauche qu’à droite, subcylindriques,

légèrement renflés à la base, leur diamètre minimal compris de 8 à 9 fois dans leur longueur ;

celle-ci en moyenne inférieure d’un quart à celle de l’écusson. Cornées hémisphériques, à peine

dilatées, le rapport de leur diamètre à la longueur des pédoncules compris entre 5,5 et 6 chez

les mâles, plus faible chez les femelles, qui sont plus petites. Écailles oculaires largement

séparées, subtriangulaires, à sommet peu aigu parfois obscurément bidenté. Pédoncules

antennulaires de même longueur ou légèrement plus longs que les pédoncules oculaires.

Pédoncules antennaires atteignant ou presque la base des cornées. Saillie antéro-latérale du

deuxième article robuste, avec quelques denticules en arrière de la pointe distale. Écaille

antennaire grêle, atteignant ou dépassant le quart proximal du dernier article pédonculaire,

armée d’une ou deux dents latérales assez fortes en arrière de son sommet et de quelques

denticules sur sa moitié proximale. Flagelle un peu plus long que la carapace.

Pièces buccales proches de celles de B. anomalus (Forest, 1989, fig.5 b, d, g, j, k ) et de

B. albicinctus. Cependant, sur l’endopodite des maxillules le processus flagelliforme latéral est

plus fort et les soies distales au nombre de 6 ; sur le mérus des 3 e maxillipèdes, il y a 2 ou 3

dents ventrales assez fortes et aiguës, avec parfois 1 ou 2 denticules accessoires.

Chélipèdes semblables et subégaux. Une fissure membraneuse longitudinale sur la face

ventrale de la coxa. Mérus robuste, ses faces latérales et mésiales peu convexes, presque planes,

bordées de tubercules du côté ventral ; ces faces ont une largeur maximale égale aux deux tiers

de la longueur de l’article. Main (fig. 4) à paume renflée, épaisse ; le rapport de sa longueur à

sa largeur maximale légèrement inférieur à 2. Région digitale à peu près aussi longue que la

région palmaire. Sur la face dorsale de la main des dents coniques, à sommet corné, dont le

développement et l’arrangement sont assez variables : elles ne sont jamais très fortes ni très

denses, n’ont pas une distribution homogène et ne sont pas alignées, mais sont relativement

plus grandes et plus rapprochées sur les portions dorso-latérale (avec une extension sur le doigt

fixe) et dorso-mésiale de la paume. Sur le bord préhensile du doigt fixe, une dent molariforme

volumineuse empiète légèrement sur l’ongle corné. La portion latérale renflée de la paume ne

porte que des tubercules aplatis. Le dactyle est armé dorsalement de dents épineuses, plus

aiguës que sur le reste de la main, et, sur son bord préhensile, de deux fortes dents triangulaires

non cornées. Sur le carpe, en dehors des dents assez fortes implantées sur la région

dorso-mésiale, la face dorsale ne porte que quelques denticules espacés.

Deuxièmes (fig. 9) et troisièmes péréiopodes un peu plus longs à droite qu’à gauche,

dépassant largement les chélipèdes. Dactyle toujours nettement plus long que le propode ;

celui-ci subcylindrique, la largeur de sa face latérale comprise entre 2,5 (P3 gauche) et 3 fois

(P3 droit) dans sa longueur. Bord ventral du mérus denticulé sur toute sa longueur sur les

deuxièmes péréiopodes, avec seulement des indentations sétifères sur les troisièmes. Tous les

articles dorsalement inermes, à l’exception d’une petite dent dorso-distale et d’une ligne dorsale

de dents à pointe cornée sur le carpe des deux paires d’appendices ; ces dents sont petites et peu

apparentes sur les troisièmes péréiopodes. Bord ventral du dactyle avec une ligne de 10-12 fines

épines cornées noires ; des épines analogues, en nombre variable, sur la face mésiale de cet

article, plus nombreuses sur les deuxièmes péréiopodes que sur les troisièmes.

Sur l’abdomen, plaques tergales 2-5 grandes, en contact quand cette partie du corps est en

— 490 —

extension. Sixième tergite divisé par une profonde dépression transverse et par une dépression

longitudinale médiane, moins marquée sur la partie antérieure ; celle-ci couverte de petites

dépressions et de tubercules aplatis, à pointe cornée orientée vers Farrière. Bord postérieur de

ce tergite inerme (fig. 12).

Telson (fig. 12) modérément asymétrique : le lobe postérieur gauche est saillant, long et

large, arrondi au sommet, le lobe droit nettement plus court, mais de forme similaire ; les deux

lobes sont séparés par une concavité régulière profonde.

Quatre pléopodes impairs (P12 à P15) dans les deux sexes, présentant les caractéristiques

décrites pour le genre.

Pilosité : Des soies fines, assez longues, en petits faisceaux espacés sur l’écusson et sur la

surface calcifiée, en arrière du sillon cervical. Sur les trois premières paires d’appendices

thoraciques des soies un peu plus épaisses, la plupart longues, implantées en faisceaux ou en

courtes rangées transverses ; ces soies sont plus denses sur les régions dorsales et latérales des

articles distaux. Les deux dernières paires thoraciques sont également assez fortement pileuses.

De longues soies fines sont présentes sur les tergites abdominaux et sur le telson, formant en

particulier des franges marginales.

Coloration (quelques semaines après la fixation) : Écusson blanc grisâtre très légèrement

rosé. En vue dorsale, le tiers proximal des pédoncules oculaires d’un rouge orange intense

s’éclaircissant vers l’avant et passant au rose uniforme sur la moitié distale. Du côté ventral le

rouge s’étend de façon variable vers l’avant, parfois jusqu’au voisinage des cornées. Les écailles

oculaires, les deux premiers articles des pédoncules antennulaires et les quatre premiers des

pédoncules antennaires d’un rouge intense ; l’article distal de ces pédoncules est rosé, la moitié

distale des flagelles antennaires rouge. Les trois premières paires thoraciques blanc jaunâtre,

avec le mérus largement teinté de rouge. Les deux dernières paires thoraciques, le sixième

tergite abdominal et les uropodes sont uniformément blanc jaunâtre. Les soies sont de teinte

fauve, celles des chélipèdes parfois légèrement rosées sur leur moitié proximale.

Remarques

Les dix spécimens d’après lesquels a été décrit Bathynarius pacificus ont une coloration

tout à fait identique. Ils présentent quelques variations dans les proportions de l’écusson qui,

chez les huit mâles, dont les tailles s’échelonnent entre 8,1 et 11 mm, a une longueur le plus

souvent nettement supérieure à sa largeur, les trois individus les plus grands ayant un

allongement maximum, avec un rapport des dimensions de 1,16 ou 1,17. Chez les deux femelles,

de 5 et 6,1 mm, longueur et largeur sont sensiblement égales. Chez tous ces exemplaires, des

sillons distincts sont visibles sur la face dorsale de l’écusson : ceux qui forment un Y inversé

sur la moitié antérieure peuvent être marqués par de fines lignes décalcifiées ou atténués et peu

apparents, alors que ceux qui forment un V aux branches arquées sur la région postérieure sont

plus profonds, toujours en grande partie décalcifiés et se prolongent parfois en une ligne

médiane jusqu’au sillon cervical.

La longueur des pédoncules oculaires varie quelque peu en fonction de la taille des

individus : ils sont relativement plus courts chez les plus grands ; leurs proportions restent

cependant à peu près les mêmes, sauf chez les plus petits, les deux femelles, où ils sont

— 491 —

Fig. 6-9. — Carpe, propode et dactyle du 2 e péréiopode gauche, vue latérale : 6, Bathynarius anomalus (A. Milne

Edwards et Bouvier), « Gerda », st. 387 (Floride), femelle 5,2 mm ; 7, B. albicinctus (Alcock), SMCB, st. 322

(Tuamotu), femelle 5,4 mm ; 8, B. wolffi sp. nov.. The Danish Expedition to the Kei Islands 1922, st. 3, mâle

holotype 5,7 mm ; 9, B. pacifiais sp. nov., SMCB, st. 303 (I. Marquises), mâle holotype 10,5 mm (x 10, sauf 9,

x 6).

— 492 —

beaucoup moins grêles, avec un indice cornéen de 4,6 chez l’une, de 5,1 chez l’autre, contre 5,7

en moyenne chez les mâles.

Le développement des dents épineuses sur la région dorsale des trois premières paires

d’appendices thoraciques semble également lié à la taille. Sur la main des chélipèdes ces dents

sont relativement plus courtes et moins nombreuses chez les petits exemplaires. De même,

ceux-ci sont moins fortement armés sur le carpe des deuxièmes péréiopodes, la femelle de

5 mm ne portant que quelques denticules localisés sur la région distale de cet article.

D’autres variations sont sans relation avec la taille des individus. Ainsi, les pédoncules des

antennules, en extension, peuvent dépasser plus ou moins largement les yeux et ceux des

antennes arriver juste à la base des cornées ou presque atteindre leur bord antérieur.

B. pacificus ne semble pas présenter d’affinités particulières avec l’une des trois autres

espèces maintenant rangées dans le genre. Il convient cependant de relever les caractères qui

le distinguent de B. albicinctus, puisque les deux espèces peuvent cohabiter. Elles ne diffèrent

pas par les proportions de l’écusson céphalothoracique ni par la forme et l’avancée du rostre

qui, chez l’un et chez l’autre, obtus, parfois émoussé au sommet, dépasse de peu les saillies

postantennaires. Les sillons de la face dorsale, tels qu’ils ont été décrits chez B. pacificus, sont

incomplètement représentés chez B. albicinctus : ils manquent ou sont à peine discernables sur

la région antérieure, alors que sur la région postérieure ils se réduisent le plus souvent à deux

faibles sillons arqués, interrompus bien avant d’atteindre la ligne médiane.

Les pédoncules oculaires diffèrent, non par leur longueur qui, chez les deux espèces, est

d’un quart à un cinquième inférieure à celle de l’écusson, mais par leurs proportions : l’indice

cornéen est en général inférieur à 5 chez B. albicinctus et le plus souvent supérieur à 5,5 chez

B. pacificus.

Les pédoncules antennulaires et antennaires sont plus courts chez B. albicinctus : les

premiers ne dépassent que de peu la base des cornées et les seconds n’atteignent pas cette base.

L’écaille antennaire est également plus courte et armée de denticules épineux plus petits et plus

nombreux que chez B. pacificus.

En ce qui concerne les chélipèdes, la forme et l’ornementation de la main séparent les deux

espèces. Chez l’une et chez l’autre, elle est approximativement deux fois plus longue que

large, mais chez B. pacificus (fig. 4) les doigts sont relativement plus courts : ils sont à peine

plus longs que la paume ; en outre, celle-ci est plus renflée. La face dorsale est couverte de dents

coniques à pointe cornée, de taille régulière dans l’ensemble, alors que chez B. albicinctus

(fig. 2) on observe un petit nombre de dents assez fortes, entre lesquelles s’intercalent de

nombreux denticules. La surface latéro-ventrale de la main, revêtue de tubercules ou denticules

cornés peu saillants chez l’espèce d’ALCOCK, ne présente chez B. pacificus que des rugosités

sétifères.

Les deuxièmes et troisièmes péréiopodes ont toujours un dactyle nettement plus long que

le propode chez B. pacificus, alors que le premier de ces articles est égal au second ou, souvent,

plus court chez B. albicinctus. Par ailleurs, ce dernier a des pattes plus grêles : ainsi, la hauteur

maximale du propode est comprise environ 3,4 fois dans sa longueur sur les P2 et 3 fois sur

les P3, les rapports homologues étant respectivement de 3 et de 2,5 chez B. pacificus.

L’ornementation est également différente : chez l’espèce nouvelle, les articles des P2 sont

dorsalement inermes, à l’exception du carpe qui porte une ligne irrégulière de dents cornées, et

du dactyle qui, ventralement, est armé d’un petit nombre d’épines cornées brunes ; sur les P3,

seul le carpe est doté d’un denticule distal. Chez B. albicinctus, carpe, propode et dactyle des

— 493 —

Fig. 10-13. — Bord postérieur du 6 e tergite abdominal et telson ( x 9) : 10, Bathynarius albicinctus (Alcock), SMCB,

st. 337 (I. Tubuaï), mâle 7,0 mm ; 11, B. anomalus (A. Milne Edwards et Bouvier), « Gerda », st. 251 (Floride), mâle

7,6 mm; 12, B. pacifiais sp. nov., SMCB, st. 303 ( I. Marquises), mâle paratype 9,5 mm; 13, B. wolfii sp. nov.,

The Danish Expedition to the Kei Islands 1922, st. 3, mâle holotype 5,7 mm.

deux paires ont une large couverture dorsale de denticules épineux dont le développement est

variable, parfois très petits et peu apparents, sur les P3 surtout.

B. pacificus se distingue encore par l’absence de denticulations sur le bord postérieur du

sixième tergite abdominal et par le telson moins asymétrique que chez B. albicinctus : son lobe

gauche est plus court et son lobe droit, non pas très arrondi, mais assez saillant.

La pilosité est assez variable chez les deux espèces, mais offre cependant dans l’ensemble

des différences spécifiques : chez B. pacificus, les soies sont un peu plus épaisses et, sur les

régions dorsales des appendices thoraciques, plus longues, plus égales et plus denses.

En dehors des caractères distinctifs énoncés ci-dessus, B. pacificus et B. albicinctus

présentent chacun une coloration particulière, persistant longtemps dans l’alcool et qui permet

leur reconnaissance immédiate. Le premier a des appendices thoraciques d’un blanc jaunâtre

uniforme et des pédoncules oculaires fortement pigmentés sur leur tiers proximal au moins.

Chez le second les pattes sont d’un rouge vermillon intense largement annelé de blanc, le rouge

étant constellé de taches et points blancs marquant les implantations de soies ; les pédoncules

oculaires sont blancs sur toute leur longueur.

Bathynarius wolfïï sp. nov.

(Fig. 5, 8, 13, 14)

Matériel examiné. — Iles Kei, The Danish Expedition to the Kei Islands 1922, station 3, 30.03.1922,

5°32 S, 132°36'E, 245 m, sable : 1 3 5,7 mm (Zoologishe Museum, Copenhague).

Type et localité-type. — Voir ci-dessus.

Coquille. — Cymatium sp.

— 494 —

Description

Écusson céphalothoracique (fig. 14) légèrement plus long que large. Bords latéraux

régulièrement convexes, avec une indentation en arrière de leur milieu. Rostre en triangle obtus,

à sommet émoussé dépassant les saillies postantennaires qui sont arrondies et inermes. Écusson

creusé de dépressions bien marquées donnant à la surface un aspect corrodé, sauf dans la partie

centrale de la région gastrique qui est simplement ponctuée. En arrière du rostre, une courte

gouttière longitudinale avec une fine ligne axiale décalcifiée. Pas de sillon transverse sur la

partie antérieure de la région cardiaque.

Pédoncules oculaires égaux, très faiblement renflés à la base, leur longueur sensiblement

égale aux trois quarts de celle de l’écusson. Cornées grandes, un peu plus longues que larges ;

leur diamètre compris 4,5 fois environ dans la longueur des pédoncules. Écailles oculaires

largement espacées, courtes, leur sommet brièvement bidenté.

Pédoncules antennulaires dépassant quelque peu les yeux.

Pédoncules antennaires atteignant juste la base des cornées. Deuxième article à angle

antéro-latéral non saillant, arrondi, à gauche, formant une courte saillie à sommet arrondi,

inerme, à droite. Écaille antennaire atteignant le tiers proximal du dernier article ; elle est

triangulaire, forte, mais faiblement armée : en arrière de son sommet peu aigu, une dent courte,

émoussée, et une dent latérale submédiane qui, à droite, est très petite, à peine discernable.

Flagelle un peu plus long que la carapace.

Chélipèdes semblables, le gauche un peu plus grand que le droit. Une large fissure

longitudinale membraneuse sur la face ventrale de la coxa. Faces latérale et mésiale du mérus

très faiblement convexes, avec des tubercules arrondis sur la moitié distale de leurs bords

ventraux ; ces faces ont une largeur maximale égale aux trois cinquièmes environ de la longueur

de l’article. Main (fig. 5) à paume renflée du côté ventral, le rapport de sa longueur à sa largeur

maximale légèrement inférieur à 2. Doigts un peu plus longs que la paume. Face dorsale

recouverte de dents coniques à pointe cornée ; ces dents sont fortes, assez rapprochées près du

bord latéral, où elles tendent à former deux lignes qui s’étendent sur le doigt fixe et dont la plus

latérale compte une dizaine de dents ; elles sont également assez rapprochées près du bord

mésial, mais sont peu nombreuses et espacées sur la région médiane. Le doigt fixe est armé

dorsalement d’épines cornées courtes et larges, quelque peu aplaties ; son bord préhensile porte

des dents molariformes dont l’une, grosse, massive, s’avance quelque peu au-dessus de la base

de l’ongle. La face latérale de la paume, nettement séparée de la face dorsale, est presque plane,

inerme, mais avec des ponctuations sétifères ; des épines cornées courtes, fortes, réapparaissent

sur la face ventrale. Le dactyle porte des dents cornées plus petites que sur le propode, mais

avec un sommet corné élargi et aplati ; son bord préhensile est armé de deux grosses dents

principales et un processus proximal triangulaire s’avance au-dessus de la base du doigt fixe.

Deuxièmes (fig. 8) et troisièmes péréiopodes plus longs à droite qu’à gauche, dépassant

largement les chélipèdes. Dactyle légèrement plus long que le propode, ce dernier article

subcylindrique, sa hauteur maximale comprise 3,2 fois dans sa longueur, sauf sur la P3 gauche

dont le propode, plus court, n’est que 2,7 fois plus long que haut. Bord ventral du mérus

denticulé sur toute sa longueur sur les P2, avec seulement des indentations sétifères sur les P3.

Sur les P2, dorsalement, le carpe est armé d’une ligne de dents à pointe cornée aiguë, fortement

inclinées vers l’avant ; le propode porte sur toute sa surface dorsale des denticules cornés

495 —

Fig. 14. — Bathynarius wolffi sp. nov., The Danish Expedition to the Kei Islands 1922, st. 3, mâle holotype 5,7 mm :

Région antérieure de la carapace et appendices sensoriels ( x 10).

arrangés en deux lignes irrégulières et des denticules similaires sont présents sur le dactyle. Les

P3 sont plus faiblement épineux, avec un seul denticule, distal, sur le carpe, et des denticules

ou spinules sur le propode et le dactyle, moins nombreux que sur les P2. On observe sur le

dactyle des deux paires une ligne ventrale de 8-10 épines cornées et des spinules sur sa face

mésiale.

Sur l’abdomen, plaques tergales 2-5 grandes, très rapprochées. Sixième tergite divisé par

une profonde dépression transverse ; un fin sillon longitudinal médian sur la partie antérieure,

— 496 —

se prolongeant sur la partie postérieure par une large dépression ; la partie antérieure est

uniformément couverte de minuscules denticules épineux. Bord postérieur de ce tergite inerme

(fig- 13).

Telson (fig. 13) avec les deux lobes postérieurs saillants, le gauche large à la base, très

arrondi au sommet, le droit plus court mais de forme similaire ; les deux lobes sont séparés par

une concavité régulière assez profonde.

Quatre pléopodes impairs, le premier légèrement plus petit que les suivants. Sur tous

l’exopodite est bien développé, l’endopodite présent, mais rudimentaire.

Pilosité : Région antérieure du corps et appendices sensoriels faiblement pileux : quelques

fines soies fasciculées sur l’écusson et des soies un peu plus longues sur l’écaille antennaire. Sur

la face dorsale des chélipèdes, des soies de longueur variable disposées en éventail à la base des

dents à pointe cornée : ces soies, assez longues sur le carpe, ont une taille décroissante à partir

de la base de la main. La région dorsale des appendices thoraciques suivants est également

revêtue de soies assez longues mais peu denses.

Coloration : L’holotype, seul spécimen connu, recueilli en 1922, est décoloré. Les

téguments calcifiés sont dans l’ensemble d’un blanc crémeux avec des reflets irisés. Cependant

on discerne sur le dactyle des pattes ambulatoires une très légère teinte rosée, avec deux

anneaux blancs, l’un proximal, l’autre distal.

Remarques

Bathynarius wolffi sp. nov. est décrit d’après un unique spécimen recueilli par Th. Mor-

tensen au large des îles Kei. La nouvelle espèce répond à la diagnose et à la définition du genre,

telles qu’elles ont été proposées lors de son établissement, sauf sur deux points : il n’y a pas

trace de sillon transverse sur la région cardiaque et le bord postérieur du sixième tergite

abdominal est inerme, comme chez B. pacificus sp. nov.

Certaines des différences qui séparent B. wolffi des deux autres Bathynarius indo-ouest

pacifiques sont minimes et devront être confirmées par l’examen d’un matériel supplémentaire,

mais d’autres sont très nettes et ne laissent place à aucune confusion.

Compte tenu des variations de B. albicinctus et de B. pacificus en fonction de la taille, le

type de B. wolffi, a été plus particulièrement comparé à des spécimens de dimensions voisines.

On ne relève pas de différences significatives dans la forme ni dans les proportions de

l’écusson, mais sa surface ne présente pas trace des lignes ou sillons sur la région gastrique,

toujours bien apparents chez B. pacificus, atténués et incomplets chez B. albicinctus. La

longueur des pédoncules oculaires rapportée à celle de l’écusson et leurs proportions sont assez

voisines chez les trois espèces. On note cependant que ces pédoncules sont légèrement plus

robustes et les cornées un peu plus grandes chez B. wolffi. Chez celui-ci, les écailles oculaires

sont, non pas unidentées, mais brièvement bidentées, et la saillie antéro-latérale du deuxième

article des pédoncules antennaires n’est pas triangulaire et denticulée, mais courte, arrondie et

inerme.

Les trois premières paires de péréiopodes se rapprochent de ceux de B. pacificus par les

proportions de leurs articles, avec des différences minimes dont la signification est douteuse,

s’agissant d’un seul individu. Par contre, leur ornementation constitue l’un des caractères qui

— 497 —

distinguent le plus nettement B. wolffi des autres Bathynarius. Ce caractère sépare sans

ambiguïté B. albicinctus de B. pacificus (supra, p. 492). Or, les dents, denticules et épines sur

ces appendices offrent encore un développement et un arrangement autres chez B. wolffi. Sur

les chélipèdes, la face dorsale de la paume (üg. 5) rappelle celle de B. pacificus dans la mesure

où elle porte des dents coniques à pointe cornée, de dimensions assez homogènes ; cependant

ces dents sont plus grandes et moins nombreuses chez le type de B. wolffi que chez des individus

de taille voisine appartenant à l’autre espèce. De plus, chez ceux-ci le doigt fixe est armé de

dents semblables à celles de la paume, quoique plus petites, c’est-à-dire qu’elles sont dressées

et ont une forte base conique calcifiée surmontée d’une petite pointe cornée ; chez B. wolffi, la

partie cornée est plus développée par rapport à la base, élargie en triangle ou arrondie, et plus

ou moins aplatie. Les deux paires thoraciques suivantes sont plus épineuses chez B. wolffi, avec

des dents ou denticules cornés sur le carpe, le propode et le dactyle des P2, et des denticules

sur le propode et le dactyle des P3, alors que chez B. pacificus seul le carpe des P2 est armé.

Le bord postérieur du sixième tergite abdominal est inerme, comme chez B. pacificus, alors

qu’il est denticulé chez B. albicinctus. Le telson des deux espèces nouvelles diffère quelque peu

dans son contour mais chez l’une et chez l’autre le lobe droit est assez saillant, alors qu’il est

très court et arrondi chez B. albicinctus.

La pilosité, telle que ce caractère, assez variable, apparaît sur le type, serait plus faible que

chez B. pacificus : les soies sont dans l’ensemble moins longues et moins denses et, sur la main

des chélipèdes, leur taille diminue rapidement à partir de la base.

Le spécimen décrit est presque complètement décoloré. Cependant, la très légère teinte

rosée visible sur une partie du dactyle des pattes ambulatoires laisserait supposer que, sur le

vivant, cet article est rouge et annelé de blanc à ses extrémités, comme chez B. albicinctus. Ceci

ne permet évidemment pas de préjuger du reste de la coloration.

Remarques complémentaires

sur les caractères et la distribution du genre Bathynarius

L’introduction de deux espèces supplémentaires dans un genre établi avec deux espèces

incluses conduit nécessairement à contrôler sa définition et sa diagnose. En fait, celles-ci se sont

trouvées en grande partie confirmées : les deux taxa nouveaux présentent, outre un habitus

similaire, la plupart des caractères auxquels avait été accordée une signification générique. C’est

le cas, entre autres, de la forme de l’écusson et du rostre, du grand développement des tergites

de l’abdomen, de la forte asymétrie du telson, du large écartement des pédoncules oculaires, et

de la structure et de l’ornementation des chélipèdes, avec l’existence d’une fissure longitudinale

membraneuse sur la face ventrale de la coxa et la couverture épineuse du carpe et de la main.

Les pièces buccales, décrites et figurées chez B. anomalus (Forest, 1989: 762, fig. 5 b, d, g, j,

k) n’offrent que des différences spécifiques minimes dans les proportions et la spinulation de

certains articles : ainsi, chez B. pacificus, le bord ventral du mérus des 3 e maxilipèdes est armé

de 2, rarement 3, dents assez aiguës , au lieu de 4-5, obtuses , chez B. anomalus. De même, la

disposition et la structure des quatre pléopodes impairs sont sensiblement les mêmes : ces

appendices sont presque égaux et le quatrième a, chez les femelles, la même fonction ovifère

que les précédents.

498 —

La définition précédemment établie nécessite cependant quelques amendements. Le plus

important, à apporter également à la diagnose, concerne le sillon transverse sur la région

cardiaque : présent chez tous les B. pacificus examinés, il manque totalement chez le type et

unique spécimen connu de B. wolffi. Deux autres points appellent des corrections d’ordre

mineur : l’un est relatif à la conformation des écailles oculaires, l’autre à celle du bord

postérieur du sixième tergite abdominal. Dans la définition du genre, les écailles oculaires ont

été notées comme unidentées. Or, chez le type de B. wolffi, elles sont brièvement bidentées ; ceci

peut cependant résulter d’une anomalie, d’autant plus que, chez certains B. pacificus, leur

sommet peut être tronqué d’un côté ou de l’autre et surmonté de deux denticules plus ou moins

distincts. Quant au sixième tergite abdominal, son bord postérieur est inerme chez les deux

espèces décrites ici, alors qu’il est denticulé chez B. anomalus et chez B. albicinctus.

Trois des espèces rangées dans le genre Bathynarius sont connues par un nombre

d’exemplaires suffisant pour qu’elles aient pu être comparées de façon significative, en tenant

compte de leur variabilité. La quatrième, bien que représentée par un spécimen unique, est

aussi incontestablement distincte. S’il est maintenant possible de confirmer que B. anomalus

diffère de B. albicinctus, non seulement par la coloration, mais par une série de traits

morphologiques, on constate également que les trois espèces indo-ouest pacifiques ne

présentent pas d’affinités particulières qui les opposeraient à celle de l’Atlantique occidental.

Au contraire, par certains caractères — ornementation des chélipèdes et des deux paires de

pattes thoraciques suivantes, proportions des articles de ces dernières — les deux espèces

nouvelles apparaissent comme plus proches de B. anomalus que de B. albicinctus.

Présentant des différences spécifiques nettes mais de peu d’ampleur, les Bathynarius vivent

dans des conditions écologiques assez voisines. Tous ont été recueillis dans des régions où

existent des formations coralliennes et à des profondeurs comparables. Les échantillons de B.

anomalus, de loin les plus nombreux dans le matériel examiné, provenaient d’une quarantaine

de stations s’échelonnant de 100 à plus de 400 m de profondeur, mais la plupart entre 200 et

300 m, alors que les trois autres espèces ont surtout été capturées entre 250 et 300 m.

La distribution géographique des Bathynarius (fig. 15) apparaît aujourd’hui, nous l’avons

dit, comme considérablement plus étendue qu’au moment où le genre a été créé. A l’Atlantique

occidental, où B. anomalus semble commun au large des Petites et Grandes Antilles, et à

l’océan Indien (sud de l’Inde et île de La Réunion) s’ajoutent l’Indonésie et la Polynésie. Cette

extension ne va pas à l’encontre de l’hypothèse d’une origine thétysienne pour le genre et, à cet

égard, rapproche celui-ci des Pylocheles (Forest, 1989 : 783).

L’homogénéité morphologique du genre Bathynarius et les similitudes qu’offrent ses

représentants dans leur écologie semblent donc aller de pair avec une très large distribution à

travers les océans. Ceci est également observé chez d’autres Diogenidae, à la fois peu diversifiés

dans leur morphologie, vivant dans des conditions écologiques relativement uniformes, en

particulier en ce qui concerne la profondeur, et présentant en même temps une vaste aire de

dispersion. C’est le cas des Clibanarius, dont les nombreuses espèces ne se distinguent guère,

souvent, que par la coloration : toutes habitent essentiellement la zone intertidale ou son

voisinage immédiat et sont communes dans les mers tropicales et subtropicales. De même, les

trois espèces du genre Petrochirus, morphologiquement assez voisines, vivent dans des limites

de profondeurs relativement étroites, surtout entre 30 et 50 m, de part et d’autre de l’Atlantique

et dans le Pacifique oriental. Au contraire, d’autres genres à grande extension géogra-

— 499

phique, tels Diogenes, Dardanus et Paguristes, présentent une forte diversification spécifique en

partie liée à des adaptations à des niveaux bathymétriques et à des conditions écologiques

différents.

Clef d’identification des espèces du genre Bathynarius

1. Bord postérieur du 6 e tergite abdominal irrégulièrement denticulé. Lobe droit du telson très

arrondi, saillant du côté latéral, mais non ou à peine du côté postérieur. 2

— Bord postérieur du 6 e tergite abdominal inerme. Lobe droit du telson ovalo-triangulaire, notablement

saillant du côté postérieur. 3

2. Main des chélipèdes recouverte de dents coniques fortes, de taille relativement uniforme. Coloration

d’ensemble rose saumon clair, fugace. — Grandes et Petites Antilles. anomalus

— Main des chélipèdes recouverte de dents de taille irrégulière, certaines assez fortes parmi de nombreux

denticules. Coloration vive persistante : les appendices thoraciques d’un rouge intense ponctué de

blanc, et cerclés de blanc. — Inde, La Réunion, îles Marquises et Tubuai. albicinctus

3. Un sillon transverse sur la région cardiaque. Bord dorsal du propode des 2 e péréiopodes inerme. —

Iles Marquises. pacificus

— Pas de sillon transverse sur la région cardiaque. Bord dorsal du propode des 2 e péréiopodes

denticulé. — Iles Kei. wolffi

— 500 —

RÉFÉRENCES BIBLIOGRAPHIQUES

Alcock, A., 1905. — Catalogue of the Indian Decapod Crustacea in the Collection of the Indian

Museum. Part II : Anomura. Fasciculus I. Pagurides. Calcutta : i-xi, 1-197, pi. 1-16.

Buitenduk, A. M., 1937. — The Paguridae of the Snellius Expedition. Biological Results of the Snellius

Expedition. IV. Temminckia, 2 : 251-280, fig. 1-19.

Fize, A., et R. Serene, 1955. — Les Pagures du Vietnam. Notes Inst, océanogr. Nhatrang, (45) : i-ix, 1-228,

fig. 1-35, pi. 1-6.

Forest, J., 1952. — Contributions à la révision des Crustacés. Paguridae. I. Le genre Trizopagurus. Mém.

Mus. natl Hist, nat., A (Zool.), 5 (1) : 1-40, fig. 1-25.

— 1989. — Sur le genre Bathynarius gen. nov. (Decapoda, Diogenidae). Bull. Mus. natl. Hist, nat., 4 e

sér., 10 , (1988), A (4) : 759-784, fig. 1-9.

Milne Edwards, A., et E.-L. Bouvier, 1893. — Description des Crustacés de la Famille des Paguriens

recueillis pendant l’Expédition. Reports on the results of dredging, under the supervision of

Alexander Agassiz, in the Gulf of Mexico (1877-78), in the Caribbean Sea (1878-79), and along the

Atlantic coast of the United States (1880), by the U. S. Coast Survey steamer «Blake»,

Lieut.-Com. C. D. Sigsbee, U. S. N., and Commander J. R. Bartlett, U. S. N., commanding,

XXXIII. Mem. Mus. comp. Zool. Harv., 14 (3) : 1-172, pi. 1-12.

Bull. Mus. natl. Hist, nat., Paris, 4 e sér., 14, 1992,

section A, n° 2 : 501-561.

Deepwater Xanthid crabs from French Polynesia

(Crustacea, Decapoda, Xanthoidea)

by Peter J. F. Davie

Abstract. — A collection of brachyuran crabs of the family Xanthidae, trapped in deepwater in

French Polynesia, has been studied. Of a total of 13 species, 10 are described as new, and four new genera

are erected : Alainodaeus gen. nov. to include A. akiaki sp. nov. and A. rimatara sp. nov. ; Epistocavea gen.

nov. to include E. mururoa sp. nov. ; Meriola gen. nov. to include M. rufomaculata sp. nov. ; and Rata

gen. nov. to include R. tuamotense sp. nov. Five species are described in existing genera : Banareia fatuhiva

sp. nov. ; Euryozius danielae sp. nov. ; Medaeus grandis sp. nov. ; Meractaea tafai sp. nov. ; and

Paraxanthodes polynesiensis sp. nov. The records of Demania garthi Guinot and Richer de Forges, 1981,

Demania mortenseni (Odhner, 1925), and Lophozozymus bertonciniae Guinot and Richer de Forges, 1981,

all represent considerable eastwardly range extensions. Actaea mortenseni Odhner, 1925, removed from

Actaea by Guinot (1976) and subsequently incertae sedis is re-described and placed into Demania for the

first time.

Résumé. — Une collection de crabes de la famille des Xanthidae, capturés en eau profonde, en

Polynésie française, au moyen de casiers, est étudiée. Sur un total de 13 espèces, 10 sont nouvelles pour

la Science. Quatre genres nouveaux sont créés : Alainodaeus pour recevoir A. akiaki sp. nov. et A. rimatara

sp. nov. ; Epistocavea pour E. mururoa sp. nov. ; Meriola pour M. rufomaculata sp. nov. ; Rata pour R.

tuamotense sp. nov. Cinq des espèces nouvelles appartiennent à des genres déjà décrits : Banareia fatuhiva,

Euryozius danielae, Medaeus grandis, Meractaea tafai et Paraxanthodes polynesiensis. Demania garthi

Guinot and Richer de Forges, 1981, D. mortenseni (Odhner, 1925) et Lophozozymus bertonciniae Guinot

and Richer de Forges, 1981, sont signalées pour la première fois en Polynésie française, ce qui étend

considérablement, vers l’est, leur aire de distribution. Actaea mortenseni Odhner, 1925, exclue du genre

Actaea par Guinot (1976) et devenue ainsi un incertae sedis, est redécrite et placée, pour la première fois,

dans le genre Demania.

Key words. — Crustacea, Brachyura, Xanthidae, deepwater fauna, trapping, Pacific Ocean, French

Polynesia.

P. J. F. Davie, Queensland Museum, P.O. Box 3300, South Brisbane, Qld. 4101 Australia

Introduction

The last 20 years have considerably improved our knowledge of the crab fauna of the

western Pacific Ocean. The MUSORSTOM I, II and III Expeditions, under the direction of

Professor Jacques Forest, in 1976, 1980 and 1985, have led to important studies of the bathyal

fauna of the Philippines (Forest, 1981, 1986 ; Serene and Vadon, 1981). The investigation of

the bathyal zone of the plateau of the Chesterfield Islands and of New Caledonia has been

— 502 —

undertaken with several cruises viz. CHALCAL I and II, BIOCAL, MUSORSTOM IV and V

(see Richer de Forges, 1990), and the results of the study of some of the collected material,

in particular the Crustacea, has been published as part of the French MUSORSTOM Series.

Along the Australian coast, the deepwater crustacean fauna has been systematically

investigated recently by the cruises of CIDARIS I, II, and III, and collections made by R.V.

‘Soela’. Papers on crabs by the following authors are beginning to fill the gaps in our

knowledge of this poorly known region (Griffin and Brown, 1976 ; Griffin and Tranter,

1986 a, b ; Davie and Short, 1989 ; and Davie and Richer de Forges (in prep.).

The present study is based on a part of the crab collections made by J. Poupin of the

French Service Mixte de Contrôle Biologique (SMCB). The collections were made from the

F.R.V. ‘Marara’ which has been carrying out a biological survey throughout French Polynesia.

Among the fishing activities, traps are set on the outer slopes of the islands in depths ranging

from 100 to 1000m. The details of the gear operations and the yields of Pandalidae shrimps

are given in Poupin et al. (1990). Poupin and Richer de Forges (1991) have briefly outlined

the study and their report stresses “ the richness and high degree of endemicity of this poorly

known area ”. Photographs taken on board vessel by J. Poupin have allowed the life colours

of several of the species to be described.

The deepwater of the central and southern Pacific Ocean is still a treasure-house of new

taxa. Guinot and Richer de Forges (1981a, b) described three new genera and twelve new

species of crabs from deepwater in the Indo-Pacific Region, and notably, ten of these species

and two of the genera are only represented in the Pacific. Of the present collection of 13 species

from just one family, the Xanthidae, 10 are new to science, and four new genera are needed

to accommodate them. Of the remaining three species, two had only been described in the

aforementioned work of Guinot and Richer de Forges (1981a, b), and only one was known

prior to the 1980s. An additional new species of xanthid crab, Hypocolpus mararae Crosnier,

1991, was also collected along with the present specimens, but has been reported on separately

by Alain Crosnier.

Abbreviations used in the text are : AM, Australian Museum, Sydney ; MNHN, Muséum

national d’Histoire naturelle, Paris ; QM, Queensland Museum, Brisbane ; USNM, Smithso¬

nian Institution, United States National Museum, Washington. The descriptions for this paper

were prepared using the DELTA computer system for generating taxonomic descriptions

(Dallwitz and Paine, 1986).

The abbreviated terminology used for carapace regions is that used by Serene (1984)

following Dana (1852). Measurements given in the text are of carapace breadth (measured at

the widest point including lateral spines) followed by length. Leg segments were measured

along the top margin and so these were not always the maximum possible length, and this

should be borne in mind when using the ratios. The exact limits of the width of the hind margin

are also sometimes difficult to determine and in this work they were defined by the point at

which the lateral carapace suture meets the rear margin.

List of species of Xanthidae trapped in deepwater

in French Polynesia

(* denotes a previous record ; the species is not further discussed in this paper).

Trichiinae De Haan, 1841

Banareia fatuhiva sp. nov.

Xanthinae MacLeay, 1838

Demania garthi Guinot and Richer de Forges, 1981

Demania mortenseni (Odhner, 1925) comb. nov.

Paraxanthodes polynesiensis sp. nov.

Euxanthinae Alcock, 1898

Alainodaeus akiaki gen. nov., sp. nov.

Alainodaeus rimatara gen. nov., sp. nov.

Epistocavea mururoa gen. nov., sp. nov.

* Hypocolpus mararae Crosnier, 1991

Medaeus grandis sp. nov.

Actaeinae Alcock, 1898

Meractaea tafai sp. nov.

Rata tuamotense gen. nov., sp. nov.

Zosiminae Alcock, 1898

Lophozozymus bertonciniae Guinot and Richer de Forges, 1981

Liomerinae Sakai, 1976

Meriola rufomaculata gen. nov., sp. nov.

Incertae sedis

Euryozius danielae sp. nov.

Family Xanthidae MacLeay, 1838

Trichiinae De Haan, 1841

Banareia fatuhiva sp. nov.

(Fig. 1 ; pi. 1)

Etymology. — The name refers to the Island of Fatu Hiva, in the Marquises Islands, near where

the paratypes were collected. It is treated here as a noun in apposition.

Type material. — The large male (MNHN-B22228) is designated as holotype. The other two

specimens are paratypes.

Material examined. — French Polynesia. SMCB (J. Poupin) : Marquises Islands : Tahuata, Stn 300,

9°54.5'S, 139°07.9'W, trapped 190 m, 1.9.1990 : 1 <$ 40.4 x 29.9 mm (MNHN-B22228). Fatu Hiva, Stn

306, 10°31.1'S, 138°39.4'W, trapped, 250 m, 4.09.1990 : 1 $ 21A x 20.5; 1$ 27.7 x 20.7 mm

(MNHN-B22229).

— 504 —

Fig. 1. — Banareia fatuhiva sp. nov. Holotype J, MNHN-B22228, Tahuata, Marquises Islands. A, frontal view ; B, third

maxilliped ; C, abdomen ; D, sternum and abdomen ; E, F, first gonopod.

Description

Carapace sub-globose c. 1.34-1.35 times broader than long. Fronto-orbital width c.

0.59-0.65 times carapace length. Carapace convex in both directions, but more flattened

posteriorly. Regions moderately defined, separated by deep, smooth, narrow grooves ; IF, 2F

and 1M fused ; 1M narrowly obliquely divided from 2M for most of length but connected at

— 505 —

inner posterior corner ; 2M completely separated from 3M ; 2M entire, not subdivided ; 3M

with anterior projection very long reaching anteriorly to level with posterior-most point of

orbit ; 4M more-or-less clearly separated from 3M ; strong grooves posterior to raised orbital

rim ; 2L wide, clearly separated, with raised granular tubercle in anterolateral corner ; lateral

regions swollen ; regions behind 2L not strongly demarcated, a narrow groove separating 4L

distinct in places, 6L more-or-less well separated ; cardiac region (IP) strongly indicated.

Anterolateral margins regularly convex ; granulated ; with four teeth behind the exorbital

angle, not strongly projecting ; first tooth an irregularly granular lobe, with posterior granules

slightly more prominent ; second and third teeth similar, in the form of granular tubercles ;

between teeth 1 and 2, and 2 and 3, are deep, smooth, narrow grooves which continue onto

the pterygostome, and meet ventrally so as to describe a triangle ; behind third tooth margin

very long, c. half total length of anterolateral margin, armed with several strong granules,

terminating in a larger granular tubercle at junction with posterolateral margin ; posterolateral

margin oblique, slightly concave, rounded. Front c. 0.21-0.24 times carapace width ; c. 0.49-0.5

times fronto-orbital width ; moderately projecting ; strongly bilobed, with very deep U-shaped

sulcus, each tooth roundly triangular ; lateral angles also bluntly acute, strongly separated from

medial teeth, but not as strongly projecting. Posterior margin c. 0.27-0.3 times carapace width.

Carapace surface with granules covering entire surface except for grooves ; granules discrete,

on average smaller medially, and larger towards anterolateral margins. Setae of medium length,

soft, covering entire surface and give a shaggy appearance. Upper orbital border evenly

granular, raised, with strongly projecting tubercular tooth medial to exorbital tooth, separated

by smooth narrow grooves ; exorbital tooth granular, also separated by deep narrow grooves.

Lower orbital border granular ; armed with two similar, large granular teeth ; sub-orbital and

sub-hepatic regions granular, granules becoming coarser dorsally. Antennal flagellum small

and entering orbit, reaching just beyond lateral edge of orbit. Basal antennal segment just

touching front ; armed distally with small, forwardly projecting, bluntly granular lobe.

Antennules folding obliquely ; epistome relatively narrow from side to side, deeply excavated,

upper lateral margins with a blunt, granular, medial tooth. Inter-antennular septum narrow.

Third maxilliped : merus distinctly shorter than ischium ; merus wider than long, length

c. 0.9 times breadth ; inner distal angle below palp produced as sharply granular tooth ; c. 0.6

times length of ischium. Ischium rectangular, length c. 1.4 times breadth; inner margin

serrated.

Chelipeds subequal ; large and robust. Merus with posterior border granulate ; with broad

sub-distal lobe ; lower border granulate ; anterior border sparsely granulate, rounded. Carpus

with inner angle not produced, but strongly angular ; inner margin granular ; upper surface and

outer margin granular like carapace ; granules present on inner face of carpus just below inner

angle. Outer surface of palm entirely covered by thick setae (like carapace) except for distal

halves of fingers ; coarsely granular, largest granules arranged in 2-3 more-or-less distinct rows.

Inner surface of palm smooth and punctate distally, but with vertical band of large rounded

granules proximally. Immovable finger moderately long, with a medial sulcus over proximal

two-thirds defined by coarsely granular ridges ; cutting margins bluntly cristate ; fixed finger

with 2-3 low teeth in proximal half ; dactyl also with 2-3 proximal teeth but very poorly

defined. Length of cutting margin of fixed finger c. 0.35 times length propodus. Ventral border

of chela concave at base of fixed finger. Dorsal surface of dactyl granular. Fingers pointed ;

without a noticeable gape between the cutting margins ; black colouring of fixed finger

— 506 —

continuing onto palm to about two-thirds of distance along ventral margin, proximal edge of

colouring oblique on outer face, but more nearly vertical on inner face.

Walking legs : relatively short ; compressed ; broad ; first pair slightly the longest, c. 1-1.1

times maximum carapace width. Merus of third leg c. 2.2 times as long as wide. Carpus c. 1.6

times as long as wide. Propodus c. 1.1 times as long as wide. Dactyli longer than propodi ;

slender and straight ; terminating in an acute chitinous tip. Merus anterior margin unarmed

terminally. Carpus with longitudinal sulcus on upper surface. All segments granular ; thickly

covered with soft setae, giving a shaggy appearance.

Male abdomen : third to fifth fused ; third segment slightly the widest. First segment c. 0.9

times width third segment. Segments three-five tapering, lateral margin of segment 3 slightly

concave. Segment six c. 1.8 times wider than long. Telson c. 0.8 times longer than wide ; evenly

rounded.

Gonopods : G1 long ; slender ; curved ; evenly tapering to pointed tip ; row of long setae

present apically on dorsal margin. G2 short ; evenly curved ; tip short.

Sternum : relatively narrow ; granular ; deeply cleft medially on segment 4 ; fused suture

line between segments 3 and 4 evident across whole width ; almost entire ventral surface

covered with thick shaggy setae like dorsal surface.

Remarks. — The combination of an entire 3M (not tripartite), the undivided 2M, and the

relatively poorly lobulated anterolateral margins, separates Banareia fatuhiva sp. nov. from all

described species except for B. banareias (Rathbun, 1911) and B. villosa Rathbun, 1906. B.

fatuhiva is clearly distinguishable from those species by having much more sharply defined

regions ; by having the grooves between the first two anterolateral teeth continuing onto the

subhepatic region ; by the very long border between the third and fourth anterolateral teeth ;

by the very long narrow median lobe of 3M ; and by the distinctive, very prominent, narrow

frontal lobes.

Distribution. — Known only from the Marquises Islands, French Polynesia. Bathymetric

range : 190-250 m.

Xanthinae MacLeay, 1838

Demania garthi Guinot and Richer de Forges, 1981

(Fig. 2 ; pi. 2)

Demania garthi Guinot and Richer de Forges, 1981a : 1121-22, pi. I, 2, 2a

Material examined. — French Polynesia. SMCB (J. Poupin) : Society Islands : Tubuai, Isles Sous

le Vent, Stn 417, 16°14.5'S, 151°47.1'E, trapped, 245 m, 13.5.1991 : 2 T 38.6 x 26.7, 49.6 x 33.8 mm

(MNHN). — Tuamotu Archipelago : Nihuru, 16°42.8'S, 142°52.8'W, trapped, 220 m, 15.11.1989 : 1 $ 45.7

x 31.6 mm (MNHN). Mururoa, 21°46.9'S, 138°55.4'W, trapped, 210 m, 30.11.1989 : 1 $ 53.4 x 37.1 ;

1 ? 51.0 x 36.0 mm (MNHN). Mururoa, 21°48.1'S, 138°55.9'W, trapped, 220 m, 2.12.1989 : 1 $ 54.0 x

37.3 mm (USNM). Mururoa, Stn 313, 21°52.3'S, 139°02.2'W, trapped, 140 m, 17.10.1990 : 1 Ç45.6 x 32.0

mm (USNM). — Austral Islands : Maria, Stn 352, 21°47.6'S, 154°42.9'W, trapped, 120 m, 8.12.1990 :

1 $ 56.7 x 40.9 mm (QM W8031). Tubuai, Stn 350, 23°20.7'S, 147°32.4'W, trapped, 200 m, 5.12.1990 :

1 $ 52.3 x 37.5 mm (MNHN).

— 507 —

Fig. 2. — Demania garthi Guinot and Richer de Forges, 1981. <J, MNFIN-Unreg., Mururoa, Tuamotu Archipelago,

30.11.1989. A, frontal view ; B, third maxilliped ; C, abdomen ; D, sternum and abdomen ; E, F, G, first gonopod ;

H, second gonopod.

Remarks. — This large distinctive species was described from a single female specimen ;

therefore an opportunity is taken here to illustrate the male for the first time.

Colour. — Predominantly reddish-orange on carapace and pereiopods, with cream to

white mainly in the grooves separating the regions, but also lightly speckled elsewhere. Chelae

with fingers reddish-orange basally, followed by a broad, brown band, fading to a dirty cream

on distal half.

— 508 —

Distribution. — Southern Pacific Ocean from New Caledonia (type locality) to French

Polynesia. These records mark a considerable easterly range extension. Bathymetric range :

200-245 m.

Demania mortenseni (Odhner, 1925) comb. nov.

(Fig. 3 ; pi. 3)

Actaea mortenseni Odhner, 1925 : 51-52, pi. 5, fig. 9. (?) Sakai, 1976 : 442-443, pi. 158, fig. 1.

[Actaea] mortenseni ; Guinot, 1976 : 204, pi. 19, fig. 4, 4a.

Material examined. — French Polynesia. SMCB (J. Poupin) : Marquises Islands : Fatu Hiva, Stn

306, 10°31.1'S, 138°39.4'W, trapped, 250 m, 4.09.1990 : 1 ? 21.4 x 15.7 mm;2J 20.9 x 15.0, 19.7 x

14.3 mm (MNHN-B22249). — Society Islands : lies Sous le Vent, Mopelia, 16°47.0'S, 153°55.8'W, depth

unknown, 9.08.1989 : 1 $21.5 x 15.0 mm (USNM). — Tuamotu Archipelago : Akiaki, 18°32'S, 139°12'W,

250-300 m, in pots, 10.06.1989 : 1 $ 19.5 x 14.0 mm (MNHN-B22248) 1 $ 18.0 x 12.7 mm (QM W8032).

Mururoa, 21°46.8'S, 138°52.1'W, 200 m, caught in pots, 28.11.1989 : 1 $ 17.9 x 12.4 mm (MNHN-

B22250). Tuamotu Arch., 350 m, caught in pots, 8.07.1985 : 1 $ 24.1 x 16.6 mm (USNM).

Description

Carapace transversely ovoid ; c. 1.38-1.44 times broader than long. Fronto-orbital width

c. 0.75-0.8 times carapace length. Carapace convex anteriorly, flat from side to side across

postero-branchial regions. Regions well defined, separated by smooth grooves ; IF and 2F

fused ; 1M moderately large, triangular, separated from 2M ; 2M large, broad not subdivided ;

3M entire, medial prolongation narrow, reaching nearly to anterior end of 1M ; 4M

distinguishable ; IL, 2L, and 3L fused into single, broad region ; 4L separated anteriorly from

1L-3L by a shallow groove, fused with 5L laterally ; 6L poorly separated from 5L ; IP broad,

poorly delimited laterally ; 2P also poorly defined, but with ridges slightly raised laterally above

posterior margin. Anterolateral margins regularly convex, granular ; with three low teeth

behind the exorbital angle ; not strongly projecting ; first tooth about half-way back along

anterolateral margin ; in front of first tooth and lateral to orbit, margin rounded, not defined ;

second and third teeth evenly spaced, slightly more prominent than first ; greatest carapace

width between second pair of teeth ; posterolateral margins convergent, straight. Front c.

0.29-0.33 times carapace width ; 0.56-0.6 times fronto-orbital width ; bilobed, margins acutely

granular ; lateral angles formed by acute large granules. Posterior margin c. 0.35-0.37 times

carapace width. Carapace surface covered in rounded granules, except in grooves separating

regions ; larger anteriorly, minute posteriorly ; more acute towards margins, especially on

smaller specimens ; without setae. Upper orbital border evenly granular ; concave ; orbital

fissures obsolete. Lower orbital border irregularly granular. Inner angle of lower orbital border

formed by a triangular tooth ; lateral edge of orbit without a notch. Antennal flagellum

entering orbit, filamentous, reaching just beyond outer orbital margin. Basal antennal segment

just touching front. Basal antennular segment with row of granules along anterior margin and

a short row anterolaterally ; palp folds obliquely, first segment moderately long, armed with

small sharp granules on outer face ; inter-antennular septum triangular ; superior margins of

epistome below antennules with a row of granules, inferior margin projecting.

Third maxilliped : merus of third maxilliped distinctly shorter than ischium. Merus c. 0.7

— 509 —

Fig. 3. — Demania mortenseni (Odhner, 1925). (J, MNHN-B22248, Akiaki, Tuamotu Archipelago. A, frontal view ; B,

third maxilliped ; C, abdomen ; D, sternum and abdomen ; E, first gonopod.

times wider than long ; antero-external angle produced, strongly angled, rounded ; 0.5-0.6 times

length of ischium. Ischium sub-rectangular, length c. 1.3-1.5 times width; inner margin

granular.

Chelipeds subequal ; large and robust, height of palm c. 0.55 times length including fixed

finger ; merus with posterior border granulate, with broad subdistal lobe ; lower border

— 510 —

angle, connected by an oblique crest to a small ventral tubercle ; inner margin granular ; upper

and outer surfaces covered with conical granules. Outer surface of palm with coarse conical

granules. Outer surface of palm without setae. Inner surface of palm sparsely granular, most

granules minute, smooth, small patch of larger granules medially. Immovable finger with

ventral granular ridge ; moderately short. Length cutting edge c. 0.34 times length propodus.

Ventral border of chela more-or-less concave at base of fixed finger. Dorsal surface of dactyl

granular. Fingers pointed ; a narrow gape between cutting margins basally.

Walking legs of medium length ; compressed ; slender ; first and second pairs sub-equal

and longer than others, very slightly longer than third pair. Longest leg c. 1.2 times maximum

carapace width. Merus of third leg c. 2.9-3.3 times as long as wide. Carpus c. 2-2.3 times as

long as wide. Propodus c. 1.6-1.9 times as long as wide. Dactyli c. 1.4-1.5 times length of

propodus. Dactyli slender and straight ; terminating in an acute chitinous recurved tip. Merus

of anterior margin terminating in a pronounced blunt tooth. Superior margins of meri with row

of bluntly acute, distally pointed tubercles, appearing serrated ; inferior margins granular,

particularly on anterior legs ; carpi and propodi with enlarged, coarse, bluntly acute tubercles

on superior margins, reducing in size across upper face, more-or-less arranged in rows ; bearing

scattered setae on margins, and forming a conspicuous row on distal inferior margins of

propodi and on upper and lower margins of dactyli.

Male abdomen relatively narrow ; five free segments ; third to fifth fused ; first segment

subequal in width to third. First segment narrow. Segments three-five tapering. Segment six c.

1.2-1.3 times wider than long. Telson longer than segment 6; triangular, rounded apically,

about as long as wide at base.

Gonopods : G1 long, reaching well past suture between sternites 4 and 5 ; slender ; curved.

Setae present ; row of long setae on dorsal margin near tip ; minute conical setae along dorsal

margin over distal half, and on ventral margin near tip ; tip pointed, hollowed, gonopore

opening subterminally. G2 short ; evenly curved ; tip short, reflexed, pointed.

Sternum smooth, punctate ; with short, deep cleft medially on sternite 4, just behind line

of fusion with sternite 3.

Remarks

The present specimens agree precisely with the published descriptions and figures in

Odhner (1925, pi. 5, fig. 9) and the photograph of the holotype in Guinot (1976, pi. 19, fig.

4, 4a). The pattern of dorsal carapace regions, the degree of granulation, the shape of the front,

and the length and armature of the legs (as can be seen on Odhner’s figure), all leave no doubt

that the identification is correct. The record of Sakai (1976) needs to be confirmed — the shape

of the anterolateral margins of the specimen he figured is appreciably different from the

holotype and from specimens in the present series. The male has not been previously described,

helping to explain why its correct generic placement has been problematical. Guinot (1976)

removed it both from Actaea and the Actaeinae without giving it a new generic position, except

to say that it was more nearly related to Xanthias and its allies. In this I agree, and further

suggest that it should rightfully belong to Demania Laurie, 1906. This genus has grown

enormously in the last 20 years and now includes about 17 species (see Ng and Yang, 1989,

for a key to currently recognised species). The generic definition is, however, rather broad, and

— 511 —

a careful review of the included species may reveal natural groupings within it, and lead to the

splitting of the genus. The type of the genus, Demania splendida Laurie, 1906, is very distinctive

and there seems to be a natural grouping around it of species, all having the superior margins

of the meri of the walking legs smoothly crested. The present species although not part of this

group, nevertheless has its closest relatives amongst the currently recognised Demania species

and is therefore included in this genus.

By having serrated dorsal margins of the meri of the walking legs, by the shape of the

carapace and the frontal margin, and by having the dorsal surface of the carapace covered with

small pointed granules, Demania mortenseni most closely resembles D. crosnieri Serène, 1984,

D. serenei Guinot and Richer de Forges, 1981, D. garthi Guinot and Richer de Forges, 1981,

and D. alcocki Deb, 1986. It is separated from the former two by having region 2M entire, and

not longitudinally divided. It differs obviously from D. alcocki by having spiniform

anterolateral teeth and small, sharp granules covering the carapace and legs. It is closest in

appearance to D. garthi but it can be separated by several characters : the less prominent

anterolateral spines ; the deflexed frontal margin with the evenly convex lobes, whereas on

garthi the frontal margin is more projecting and the lobes more sinuous ; the walking legs, and

in particular the meri are relatively shorter ; the fingers of the chelipeds are shorter ; the male

first pleopods differ ; and finally, mortenseni is a much smaller species. The regional definition

is almost identical on both species, and the shapes of the sternums and male abdomens are very

similar. D. mortenseni resembles members of the Actaeinae in the shape of the deflexed and

rounded frontal margin, and in the relatively short fingers of the chelipeds, but these could be

considered convergences, as the other similarities to the Xanthinae are so great.

Distribution. — Kei Islands, Micronesia, (5°37’10'S, 132°23'W), type locality, to

Tuamotu Archipelago, French Polynesia (21°47'S, 138°52'W). Bathymetric range : 200-350 m.

PARAXANTHODES Guinot, 1968

Paraxanthodes Guinot, 1968a : 723-726; 1971 : 1069. Sakai, 1976 : 432. Serene, 1984 : 208-209.

Paraxanthodes Guinot, 1968, was established to receive two species : Micropanope

obtusidens Sakai, 1965 (type species), and Xanthodes cumatodes McGilchrist, 1905. The

description of Paraxanthodes polynesiensis sp. nov. brings the total to three. The new species

is quite distinctive, differing markedly from the two already known species, but these

differences are mostly superficial and not of generic significance. An updated generic diagnosis

is given.

Diagnosis. — Carapace transversely oval or hexagonal, c. 1.4- 1.5 times wider than long ; regions well

defined ; 1M fused to inner branch of 2M ; 2M partially divided into three parts by longitudinal grooves,

outer groove more-or-less obvious ; 4M more-or-less distinct ; surface may be coarsely granular and

roughened, or minutely granular ; front slightly to moderately projecting, bilobed, lobes well separated or

abutting for most of length, lateral angles of front projecting ; anterolateral margins with 4 teeth behind

exorbital angle, surface adjacent to orbit rugose and granular, first tooth may be connected by granular

ridge with orbit (polynesiensis ) otherwise margin poorly defined and continuing onto sub-hepatic region

sometimes with 1-2 larger granular tubercles, posterolateral borders strongly convergent. Merus of third

maxilliped with antero-external angle produced. Efferent branchial ridges extending anteriorly to meet

— 512 —

epistome ; lacinie of maxilliped 1 with inner expansion relatively short and truncated. Chelipeds

moderately unequal, similar in form but smaller cheliped more slender and with fingers longer ; fingers

pointed. Walking legs moderately long, compressed, with superior margins varying from minutely

granular to serrated, and sometimes slightly cristate. Male abdomen relatively narrow, third to fifth

segments fused. Telson rounded. Male gonopod 1, long, slender, curved, tip reflexed and more-or-less

elongated.

Paraxanthodes polynesiensis sp. nov.

(Fig. 4 ; pi. 4)

Etymology. — Named in reference to Polynesia, from where the only specimens are so far known.

Type material. — The male, 20.8 x 15.1 mm, from Tuamotu Archipelago, is designated the

holotype. All other specimens are paratypic.

Material examined. — French Polynesia. SMCB (J. Poupin) : Marquises Islands : Tahuata, Stn 300,

9°54.5'S, 139°07.9'W, trapped, 190 m, 1.09.1990 : 2 9 24.4 x 17.5, 22.6 x 16.7; 1 $ 32.5 x 23.6 mm

(MNHN-B22227). Fatu Hiva, Stn 306, 10°31.1'S, 138°39.4'W, trapped, 250 m, 4.09.1990 : 1 9 19.3 x 14.2

mm (MNHN-B22226). — Tuamotu Archipelago : Mururoa, 21°46.8'S, 138°52.1'W, trapped, 200 m,

28.11.1989 : 1 $ 20.8 x 15.1 mm (MNHN-B22225)

Description

Carapace transversely ovoid, c. 1.38-1.39 times broader than long. Fronto-orbital width c.

0.67-0.75 times carapace length. Carapace convex anteriorly, flat from side to side across

posterobranchial regions but depressed laterally. Regions well defined : IF and 2F not

demarcated; 1M fused with inner branch of 2M posteriorly, anterior margin prominent,

straight, slightly oblique ; 2M partially divided by a broad longitudinal groove, outer branch

about twice width of inner branch, outer branch itself partly sub-divided by a shallower short,

narrow groove with outer part narrower than inner part ; 3M entire, reaching to about middle

of 1M ; 4M not strongly separated ; 2L, 4L, and 5L all clearly separated, 4L confluent laterally

with third anterolateral tooth ; 6L poorly and incompletely separated from 5L by shallow

grooves ; cardiac region (IP) relatively broad, oval, moderately well defined by shallow

grooves ; intestinal region narrow. Anterolateral margins regularly convex ; cristate ; with four

teeth behind the exorbital angle ; teeth evenly spaced, all of similar size and broadly triangular,

third tooth slightly the largest ; first tooth well separated from, and slightly behind, orbit,

connected to exorbital angle by a bluntly rounded crest ; below this crest, lateral to orbit,

surface uneven with raised clumps of granules ; posterolateral margins oblique, straight, about

same length as anterolateral margins. Front c. 0.28-0.31 times carapace width; c. 0.56-0.57

times fronto-orbital width ; not deflexed, strongly projecting ; bilobed, lobes straight and

oblique laterally, or moderately convex ; lobes abutting and fused over most of length but with

obvious median incision ; lateral angles rounded, narrow, noticeably produced. Posterior

margin c. 0.4-0.5 times carapace width, relatively wider in females. Carapace surface entirely

covered with minute rounded granules except for central part of grooves ; without setae. Upper

orbital border minutely granular ; concave ; lateral truncate tooth formed by fused lateral

fissures. Lower orbital border of inner angle formed by a triangular tooth ; a second,

similar-sized tooth laterally ; with V-shaped notch at outer edge. Antennal flagellum small and

entering orbit, fine, reaching a little beyond outer orbital edge. Basal antennal segment just

— 514 —

touching front. Basal antennular segment relatively broad, with raised minutely granulate rim

on superior and lateral margins ; first segment of palp moderately long, granulate on outer

surface, palp folding obliquely ; epistome relatively flat, lower margin not strongly produced ;

inter-antennular septum triangular, with margins raised and minutely granular.

Third maxilliped : merus distinctly shorter than ischium, wider than long, length c. 0.75

times width ; outer surface granulate ; antero-external angle produced, rounded ; 0.5 times

length of ischium. Ischium sub-rectangular, length c. 1.7 times breadth.

Chelipeds noticeably unequal, either may be larger ; large and robust ; palm height c. 0.5

times length including fixed finger. Merus with posterior border convex, coarsely granulate ;

lower border microscopically granulate, rounded ; anterior border minutely granulate,

rounded ; carpus with a broad tooth at inner angle ; a second, smaller granular tooth,

ventro-proximally ; inner margin minutely granular ; upper and outer surface rugose, minutely

granular. Outer surface of palm smooth and punctate ventrally, becoming minutely granular

and slightly vertically striated dorsally ; a strong, broad, longitudinal, sub-dorsal groove ; and

a narrow longitudinal groove along superior margin visible from above. Outer surface of palm

without setae. Inner surface of palm smooth. Immovable finger long (smaller chela with fingers

longer than major chela) ; with ventral ridge. Length of cutting edge c. 0.4 times length of

propodus. Ventral border of chela concave at base of fixed finger. Dorsal surface of dactyl

smooth, rounded, punctate. Fingers pointed, tips curved ; a narrow gape between cutting

margins.

Walking legs of medium length ; compressed ; first three pairs all of similar length, c.

1.1-1.2 times maximum carapace width. Merus of third leg c. 2.8-3.4 times as long as wide.

Carpus c. 2.2-2A times as long as wide. Propodus c. 1.4-1.9 times as long as wide. Dactyli c.

1.5-1.9 times length of propodus. Dactyli slender, straight, with a strong, longitudinal, lateral

furrow ; terminating in an acute chitinous recurved tip. Merus anterior margin terminating in

a blunt tooth. Carpus with accessory carinae on upper surface, superior margin of carpus

moderately carinate on last leg, but less so on anterior legs. Meri with coarse granules along

superior margin, with band of smaller granules on inferior surface ; other segments covered in

minute granules. Setae mostly sparse and on margins ; but forming a thick, short tomentum

proximally, and on inferior margin of propodi ; and on dactyli except for lateral grooves.

Male abdomen relatively narrow ; five free segments ; third to fifth fused ; third segment

the widest. First segment 0.85 times width of third segment. Segments three-five tapering.

Segment six c. 1.4-1.6 times wider than long. Telson c. 0.75 times longer than wide ; evenly

rounded.

Gonopods : G1 medium length, not quite reaching suture between sternites 4 and 5 ;

moderately stout, moderately compressed, ventro-medially slightly lamelliform ; curved ; tip

slightly recurved, tapering to very fine point ; row of stout setae present on dorsal margin

behind tip ; minute conical setae on distal half of dorsal margin, and ventrally near tip. G2

short ; evenly curved ; tip short, reflexed, pointed.

Sternum evenly covered in minute granules, male sternum with short medial longitudinal

incision on segment four.

Colouration. — On preserved material, colour predominantly orange-brown ; a broad

band of reddish pink on pterygostome above base of chelipeds ; fingers blackened, dark colour

not extending onto palm.

— 515 —

Remarks. — Paraxanthodes polynesiensis sp. nov. is easily separated from the other two

species, P. obtusidens (Sakai) and P. cumatodes (McGilchrist) by having : the dorsal surface of

carapace very finely granular, rather than coarsely granular ; the regions lower and less strongly

swollen ; the front less deflexed, more projecting and lamelliform, with the median incision less

obvious ; and the unarmed walking legs.

Distribution. — Known only from French Polynesia, between the Marquises Islands in

the north and the Tuamotu Archipelago in the south. Bathymetric range : 190-250 m.

Euxanthinae Alcock, 1898

ALAINODAEUS gen. nov.

Etymology. — Named in honour of Alain Crosnier, using his first name in combination with

“ daeus ” from Medaeus.

Type species. — Alainodaeus akiaki, by original designation. Gender is masculine.

Diagnosis. — Carapace transversely ovoid, c. 1.4-1. 6 times broader than long. Regions moderately

defined ; 2M at least partially divided longitudinally, outer branch very broad and rounded. Anterolateral

margins with four teeth behind exorbital angle ; margin anterior to first tooth poorly defined. Front c.

0.25-0.35 times carapace width ; moderately deflexed, not projecting ; bilobed, with small but obvious,

blunt, medial and lateral teeth. Posterior margin c. 0.35-0.45 times carapace width. Upper orbital border

concave, lateral fissures obvious or only slightly indicated. Lower orbital border with an inner and outer

triangular tooth ; with V-shaped notch at outer edge. Antennal flagellum relatively small and entering

orbit. Basal antennal segment just touching front. Basal antennular segment relatively broad, with raised

granular rim across upper and lateral margins ; second segment relatively long ; palp folding horizontally.

Interantennular septum relatively broadly triangular, with lateral margins only slightly concave. Third

maxilliped with merus c. 0.5 times length of ischium ; wider than long, antero-extemal angle slightly

produced. Palp articulating at inner distal margin of merus. Chelipeds large and robust ; markedly

unequal, carpus with a broad spine at inner angle ; 1 -3 smaller spines ventro-proximal to major spine.

Ventral border of chela concave at base of fixed finger. Fingers pointed, tips recurved ; without a

noticeable gape between cutting margins. Walking legs relatively long ; slightly flattened ; slender. Merus

of anterior margin terminating in a blunt tooth ; dactyli slender, straight, and flattened, with an acute,

chitinous tip. Male abdomen relatively narrow ; five free segments ; third to fifth fused. Male first gonopod

of medium length ; stout ; broadly flanged over proximal two-thirds, quickly tapering distally ; without

long setae. Sternum relatively broad ; fused sternites 3-4 with deep, median, longitudinal cleft.

Remarks

The two species included in this new genus are Alainodaeus akiaki sp. nov. and A. rimatara

sp. nov. Alainodaeus species are most closely allied to those of Monodaeus and Medaeops, both

in the general form of the carapace and more specifically by the shape of the male first pleopod

which has a lateral flange over its proximal two-thirds and then narrows abruptly [see Guinot,

1967, figs 37 and 40, for Monodaeus tuberculidens (Rathbun) and Medaeops granulosus

(Haswell) respectively].

— 516 —

Alainodaeus differs from both those genera by the following characters : 1, the regions of

the carapace are less well defined, and differ in shape — in particular, 2M is much larger and

broader, less obviously longitudinally divided, and the outer half is much wider than the inner

half ; 2, the frontal margin is not straight but consists of a pair of small median prominences

and a pair of broad, moderately convex lateral lobes ; 3, the epistome is different in shape, with

the upper margins below the antennules being less concave, so that the inter-antennular septum

is more broadly triangular ; 4, the sixth segment of the male abdomen is much broader in

comparison to its length (almost 2 times) and the margins are subparallel, whereas in the other

two genera it is relatively longer c. 1.4-1.6 times, and tends to be noticeably wider distally ; 5,

the walking legs are relatively much longer and very slender, a condition approached only by

Monodaeus rouxi (Capart) ; 6, the fingers of the minor cheliped are very long, noticeably longer

than in the related genera ; 7, the male first pleopod lacks long setae terminally.

Besides the above unique characters shared by the two new species, Alainodaeus further

differs from Monodaeus by the shape and size of the lacinia of the endopodite of maxilliped 1.

In Monodaeus it is large and expanded towards the medial line of the roof of the buccal cavity ;

but in Alainodaeus (like in Medaeops) it is much smaller and confined to the lateral part of the

buccal cavity, where it lies against the strongly defined ridge of the efferent branchial channel.

This ridge is poorly indicated in Monodaeus and also closer to the medial line.

Alainodaeus further differs from Medaeops by having the front not or only slightly

projecting, and having the second segment of the antennules much longer and folding almost

horizontally. Medaeops typically has a noticeably projecting frontal margin and the antennules

are rather short and fold more obliquely (see for comparison Guinot, 1967, fig. 21).

Alainodaeus differs from Paramedaeus in many characters. In particular, Paramedaeus has

subequal chelae ; a different type of male first pleopod with the tip bearing long setae (see

Serene, 1984, figs 50, 51) ; and much more projecting carapace regions.

Alainodaeus akiaki sp. nov.

(Fig. 5 ; pi. 5)

Etymology. — Named after Akiaki Island, part of the Tuamotu Archipelago, in French Polynesia.

It is treated here as a noun in apposition.

Type material. — The male (MNHN-B22243) from Rurutu Island, Austral Islands, is designated

holotype. All other specimens examined are paratypic.

Material examined. — French Polynesia. SMCB (J. Poupin) : Tuamotu Archipelago : Akiaki,

18°32'S, 139°12'W, 250-300 m, in pots, 10.06.1989 : 2 A 33.8 x 22.6 mm, 36.7 x 23.6 mm

(MNHN-B22241). — Austral Islands : Maria, Stn 352, 21°47.6'S, 154°42.9'W, trapped, 120 m, 8.12.1990 :

1 £ 32.5 x 20.9 mm (QM W8035). Rurutu, 22°27.8'S, 151°22.9'W, 230-240 m, caught in pots, 10.03.1989 :

1 (? 29.2 x 19.4 mm (MNHN-B22243). Ibid. 1 A 27.9 x 18.2 mm (MNHN-B22242). Rimatara, 22°38.2'S,

152°49.7'W, 300 m, caught in pots, 11.03.1989 : 1 $ 29.2 x 19.4 mm (MNHN-B22240). Raivavae,

23°51.4'S, 147°44.5'W, 350 m, caught in pots, 1.03. 1989 : 1 $ 34.4 x 22.2 mm (USNM).

— 517 —

Fig. 5. — Alainodaeus akiaki gen. nov., sp. nov. Holotype MNHN-B22243, Rurutu, Austral Islands. A, frontal view ;

B, abdomen ; C, D, first gonopod ; E, third maxilliped ; F, second gonopod ; G, sternum and abdomen.

Description

Carapace transversely ovoid, c. 1.5-1.6 times broader than long. Fronto-orbital width c.

0.7 times carapace length. Carapace moderately vaulted ; strongly convex longitudinally over

anterior third, only slightly from side to side. Regions moderately defined ; 2M separated from

3M and 2M partially divided longitudinally by a short, shallow, ill-defined groove, outer

branch of 2M very broad and rounded, c. twice width of internal branch ; 1 F and 2F not

differentiated ; 1M fused to internal branch of 2M ; 4M not clearly distinguishable ; 1L and 3L

— 518

not differentiated ; 2L and 4L distinct ; 5L and 6L also distinct, partially fused ; IP and 2P

more-or-less obvious ; 1R, 2R, 3R not distinguishable. Anterolateral margins regularly convex ;

with four teeth behind the exorbital angle ; margins granular, first tooth not prominent,

situated a little behind and well separated from orbit ; anterior to first tooth clear marginal

definition lost, a slight indication of a granular row connecting with orbit and a second

continuing obliquely below orbit ; second tooth broadly triangular, third tooth most prominent

and sharply pointed, fourth tooth similar to third, but smaller ; greatest carapace width

between third anterolateral teeth, but distance between fourth teeth only slightly less. Front c.

0.25 times carapace width ; c. 0.55 times fronto-orbital width ; moderately deflexed, not

projecting ; bilobed, with small, but obvious, blunt, medial and lateral teeth, convex between ;

pre-orbital teeth present, bluntly granular. Posterior margin c. 0.35-0.4 times carapace width.

Surface of carapace granulate except in furrows separating regions ; granules slightly larger and

more widely spaced anteriorly ; without setae. Upper orbital border concave, evenly granular,

lateral fissure obsolete, slightly indicated. Lower orbital border evenly granular ; inner angle

formed by a triangular tooth ; a second, bluntly granular tooth laterally ; with V-shaped notch

at outer edge. Antennal flagellum small and entering orbit, reaching slightly farther than lateral

edge of orbit. Basal antennal segment just touching front. Basal antennular segment relatively

broad, with raised granular rim across upper and lateral margins ; second segment relatively

long ; palp folding horizontally. Inter-antennular septum moderately wide basally ; inner

margins of antennular fossae oblique and only moderately concave ; interantennular septum

relatively broadly triangular ; lower margin of epistome slightly projecting as thin rim.

Third maxilliped : merus c. 0.5 times length of ischium ; wider than long, length c. 0.7

times width ; antero-extemal angle slightly produced, rounded. Ischium rectangular ; inner

margin granular. Palp articulating at inner distal margin of merus.

Chelipeds large and robust ; markedly unequal, right cheliped the larger on all present

specimens ; minor cheliped of similar form but more slender and with longer fingers ; merus

with posterior border sharply granulate ; without distinct subdistal spine ; lower border armed

with spinules ; frontal face of merus armed with sharp granules ; small spines especially near

upper and lower margins ; carpus with a broad spine at inner angle ; inner margin armed with

small spines, at least 1 and sometimes 2-3 smaller prominent spines ventro-proximal to major

spine ; outer margin and upper surface granular. Outer surface of palm coarsely granular ;

without setae. Inner surface of palm granular, granules finer than on outer surface ; also with

a row of 4-6 inwardly directed spines on inner edge of superior margin ; and an uneven row

of more numerous spines on ventral margin continuing along bottom edge of fixed finger nearly

to beginning of darker colouring ; a third longitudinal row of more prominent sharp granules

below middle of inner surface. Immovable finger long, rounded on outer surface ; with ventral

ridge extending from base to tip ; length of cutting edge c. 0.4 times length of propodus on

major chela, c. 0.5 on minor chela. Ventral border of chela concave at base of fixed finger.

Dorsal surface of dactyl finely granular. Fingers pointed, tips fine and markedly recurved ;

cutting margin of immoveable finger with 4 prominent triangular teeth, evenly spaced, sharply

pointed on minor chela, blunt on major chela ; cutting margin of dactyl with 3 prominent

triangular teeth in the proximal half and a fourth less clearly differentiated tooth in distal half,

teeth better developed on major chela ; without a noticeable gape between the cutting margins.

Walking legs relatively long ; slightly flattened ; slender ; second and third pairs sub-equal,

longer than others, c. 1.3 times maximum carapace width. Merus of third leg c. 4-4.6 times as

- 519 —

long as wide. Carpus c. 2.5-3 times as long as wide. Propodus c. 2.3-2.7 times as long as wide.

Dactyli c. 1.2 times length of propodus. Dactyli slender, straight, and flattened; terminating

in an acute chitinous tip. Merus anterior margin terminating in a blunt tooth. Carpus with

accessory carinae on upper surface. All segments granular, with slightly more prominent row

of spinules along upper margins of meri, and on antero-ventral borders, particularly of first two

pairs ; granules generally sharper on carpi and propodi ; setae generally lacking, but very short,

sparse setae between granules on carpi and propodi, which become slightly longer and thicker

and completely cover dactyli.

Male abdomen relatively narrow ; five free segments ; third to fifth fused ; third segment

widest. First segment c. 0.8 times width third segment. Segments three-five tapering. Segment

six c. 1.8-1.9 times wider than long. Telson c. 0.65-0.7 times longer than wide ; slightly longer

than sixth segment ; bluntly pointed and triangular.

Gonopods : G1 medium length ; stout ; broadly flanged over proximal two-thirds, quickly

tapering distally to a bluntly acute, slightly twisted tip ; without long setae, bearing only minute

bristles on distal half. G2 moderately long ; evenly curved ; tip short, recurved.

Sternum relatively broad ; fused sternites 3/4 with deep median, longitudinal cleft.

Distribution. — Known only from French Polynesia, from Tuamotu Archipelago,

18°32'S, 139°12'W, to the Austral Islands, 23°51.4'S, 147°44.5'W. Bathymetric range : 230-

350 m.

Alainodaeus rimatara sp. nov.

(Fig. 6 ; pi. 6)

Etymology. — Named after Rimatara, part of the Austral Islands Group, in French Polynesia. It

is treated here as a noun in apposition.

Type material. — The male 22.4 x 15.3 mm (MNHN-B22244) is the holotype. All other specimens

listed are paratypes.

Material examined. — French Polynesia. SMCB (J. Poupin) : Tuamotu Archipelago : Takapoto,

14°40.0'S, 145°15.2'W, trapped, 250 m, 7.06.1989 : 1 d 15.9 x 12.0 mm, 1 ? 17.4 x 12.1 mm (USNM).

Hao, Stn 246, 18°04.5'S, I41°01.6'W, trapped, 90 m, 2.06.1990 : 1 d 14.6 x 10.0 mm (QM). Akiaki,

18°32'S, 139°12'W, trapped, 250-300 m, 10.06.1989 : 1 d 22.4 x 15.3 mm (MNHN-B22244). Fangataufa,

Stn 231, 22°12.0'S, 138°45.9'W, trapped, 270 m, 21.05.1990 : 1 ? 16.2 x 11.4 mm (MNHN-B22245). -

Austral Islands : Rimatara, 22°38.2'S, 152°49.7'W, trapped, 300 m, 11.03.1989 : 1 d 21.8 x 14.6 mm

(MNHN-B22247). Raivavae, 23°51.4'S, 147°44.5'W, trapped, 350 m, 1.03.1989 : 1 $ 18.0 x 13.2 mm

(MNHN-B22246)

Description

Carapace transversely ovoid ; c. 1.44-1.5 times broader than long. Fronto-orbital width c.

0.89-0.93 times carapace length. Carapace moderately vaulted ; convex longitudinally especially

over anterior third, only slightly from side to side. Regions moderately defined ; slightly raised

transverse granular rim behind frontal margin, otherwise IF and 2F not differentiated; 1M

6. — Alainodaeus rimatara gen. nov., sp. nov. Holotype .J, MNHN-B22244, Akiaki, Tuamotu Archipelago. A,

frontal view ; B, third maxilliped ; C, abdomen ; D, sternum and abdomen ; E, F, G, first gonopod (F, abdominal

view of tip ; G, sternal view of tip) ; H, second gonopod.

— 521 —

fused to internal branch of 2M ; 2M separated from 3M ; 2M partially longitudinally divided

by a short, shallow ill-defined groove, scarcely apparent on some specimens, outer branch very

broad and rounded, c. twice width of internal branch ; 4M not clearly distinguishable on most

specimens, sometimes present as slightly raised narrow transverse strip on posterior of 3M ; 1L

and 3L not differentiated ; 2L and 4L distinct ; 5L and 6L also distinct, partially fused ; IP and

2P more-or-less obvious ; 1R and 2R not clearly distinct, separated from 3R by shallow groove.

Anterolateral margins regularly convex ; with four teeth behind the exorbital angle ; margins

granular ; first tooth barely distinct, marked only by slightly raised granules medially on broad

convexity lateral to orbit ; margin anterior to first tooth poorly defined, but continuing towards

outer edge of orbit ; an area of slightly larger sharper granules continuing obliquely below orbit

towards mouth frame ; second anterolateral tooth sharply pointed, forwardly directed ; third

tooth more evenly triangular, pointed laterally ; greatest carapace distance between third teeth ;

fourth tooth smaller, narrower, set relatively close behind third tooth. Front c. 0.33-0.36 times

carapace width ; c. 0.55 times fronto-orbital width ; moderately deflexed, not projecting ;

bilobed, with small but obvious, blunt, medial and lateral teeth ; pointed, granular, pre-orbital

teeth present. Posterior margin c. 0.37-0.44 times carapace width. Carapace surface granulate

except in smooth furrows separating regions ; without setae. Upper orbital border evenly

granular, concave, median and lateral fissures obviously indicated. Lower orbital border evenly

granular ; inner angle formed by a bluntly pointed, granular lobe ; with second, lower, broader

lobe laterally ; with V-shaped notch at outer edge. Antennal flagellum entering orbit, fine,

reaching laterally almost to level of second anterolateral tooth. Basal antennal segment just

touching front. Basal antennular segment relatively broad, with raised granular rim across

upper and lateral margins, upper margin concave, leaving gap when palp folded ; second

segment relatively long, palp folding horizontally. Inter-antennular septum moderately wide

basally ; inner margins of antennular fossae oblique and only moderately concave ; interan-

tennular septum relatively broadly triangular ; lower margin of epistome slightly projecting as

thin rim.

Third maxilliped : merus distinctly shorter than ischium ; wider than long, length c. 0.75

times width ; antero-external angle slightly produced, rounded ; c. 0.5 times length of ischium.

Ischium rectangular ; inner margin minutely granular. Palp articulating at inner distal margin

of merus.

Chelipeds large and robust ; markedly unequal, right cheliped normally the larger but

on holotype, the left ; minor cheliped of similar form but more slender and with longer fingers.

Merus with posterior border tuberculate ; without distinct subdistal spine ; lower border

granulate distally ; anterior border coarsely granulate. Carpus with a broad spine at inner

angle, armed with accessory spinules ; a second similar but slightly smaller spine ventro-

proximal to major spine, finer and more acute, also armed with accessory spinules ; outer

margin and upper surface granular. Outer surface of palm appearing smooth but microsco¬

pically granular ventrally and medially, granules becoming more coarse dorsally and

proximally. Outer surface of palm naked. Inner surface of palm appearing smooth, but

microscopically granular ; with row of 3-5 inwardly directed small spines on inner edge

of superior margin, very obvious in dorsal view. Immovable finger long, rounded on outer

surface ; with ventral ridge extending from base to tip ; length cutting edge c. 0.4 times length

propodus on major chela, c. 0.5 on minor chela. Ventral border of chela concave at base of

fixed finger. Dorsal surface of dactyl very finely granular, coarser near base. Fingers pointed,

— 522 —

recurved ; minor chela with cutting margins cristate, fixed finger with 3-4 prominent triangular

teeth, dactyl with teeth poorly differentiated ; major chela similarly armed but teeth becoming

molariform proximally, dactylar teeth well defined, with large, rounded, backwardly directed,

peg-like tooth at base ; without a noticeable gape between the cutting margins.

Walking legs relatively long ; compressed ; slender ; third pair the longest, slightly longer

than second, c. 1.3-1.4 times maximum carapace width. Merus of third leg c. 4-4.5 times as long

as wide. Carpus c. 2.8 times as long as wide. Propodus c. 2.7-2.9 times as long as wide. Dactyli

c. 1.3 times length of propodus. Dactyli slender, straight, flattened; terminating in an acute

chitinous tip. Anterior margin of merus terminating in a blunt tooth. Carpus with accessory

carinae on upper surface. All segments granular, with 2 rows of spinules, or sharp granules,

along upper borders of meri, anterior row more prominent ; a similar row along anteroventral

borders of meri, most obviously on first two pairs ; granules generally sharper on carpi and

propodi ; occasional fine setae on borders of segments, more common distally ; short setae on

upper and lower borders of propodi and dactyli.

Male abdomen relatively narrow ; five free segments ; third to fifth fused ; third segment

the widest. First segment c. 0.85 times width third segment. Segments three-five tapering.

Segment six c. 1.75-1.85 times wider than long. Telson c. 0.65 times longer than wide, very

slightly longer than sixth segment ; bluntly pointed, rounded.

Gonopods : G1 medium length ; stout, broadly flanged over proximal two-thirds, quickly

tapering distally to a bluntly acute, slightly twisted tip ; without long setae, bearing only minute

bristles on distal half. G2 moderately long ; evenly curved ; tip short, recurved.

Sternum relatively broad ; fused sternites 3/4 with deep median longitudinal cleft ; surface

finely granular.

Remarks. — Alainodaeus rimatara sp. nov. differs from A. akiaki sp. nov. in several

obvious characters. The frontal margin is slightly more prominent and the frontal region less

convex ; the first anterolateral tooth is almost obsolete ; the outer face of palm of cheliped

bearing only dorsal granulation but otherwise smooth, whereas in A. akiaki the outer face is

completely covered with granules ; and, similarly, the inner face of the cheliped palm is smooth

below the inner dorsal row of spines, and lacks both the median and ventral rows of spinules

characteristic of A. akiaki.

Distribution. — Known only from French Polynesia, from Tuamotu Archipelago,

14°40.0'S, 145°15.2'W, to the Austral Islands, 23°51.4'S, 147°44.5'W. Bathymetric range :

90-350 m.

EPISTOCAVEA gen. nov.

Etymology. — From ‘epistome’ and the latin cavea meaning an excavated hollow place. Gender is

feminine.

Type species. — Epistocavea mururoa sp. nov., here designated.

Diagnosis. — Carapace transversely ovoid, c. 1.4-1.5 times broader than long. Regions moderately

defined. Anterolateral margins regularly convex ; more-or-less carinate ; divided into 4 teeth ; continue in

— 523 —

an arc below orbit to meet anterolateral corner of buccal frame ; meri of third maxillipeds sharply angled

backwards over distal third, forming a concave shelf, and fitting against epistome, completely sealing

buccal cavity ; with maxillipeds in place a continuous convex arc formed with anterolateral margins ;

whole region across front from below orbits deeply excavated. Front moderately projecting, with medial

notch. Posterior margin c. 0.4 times carapace width. Upper orbital border concave ; orbital fissures

obsolete. Inner angle of lower orbital border formed by a triangular tooth. Basal segment of antenna

broadly in contact with front ; antennal flagellum entering orbit. Basal antennular segment triangular,

flagellum folding obliquely. Inter-antennular septum narrow. Chelipeds markedly unequal, large and

robust ; carpus with a broad tooth at inner angle and on inner face below inner angle ; ventral border of

chela concave at base of fixed finger ; fingers pointed ; a narrow gape between cutting margins. Walking

legs of medium length ; flattened ; moderately slender ; second pair the longest ; dactyli stout, straight, and

flattened, terminating in an acute, chitinous tip ; anterior margin of merus unarmed terminally. Male

abdomen relatively narrow ; five free segments ; third to fifth fused. Male first gonopod of medium length,

slender, curved. Sternum relatively broad.

Remarks

Epistocavea clearly belongs to the Euxanthinae because the anterolateral margins do not

meet the exorbital angle but continue below the orbit across the sub-hepatic region to meet the

buccal frame. It must be placed closest to those genera that have the posterolateral borders

relatively longer, less strongly convergent and not strongly hollowed out to receive the walking

legs i.e. Medaeops, Medaeus, Monodaeus, Paramedaeus. It lacks the strongly defined 4M of

Medaeus, the relatively slender legs of Monodaeus, and has shorter anterolateral margins than

Paramedaeus.

In overall conformation of the carapace and chelipeds Epistocavea most closely resembles

species of Medaeops. It is easily separated from all related genera by the broad, deeply concave

epistome and sub-hepatic regions, and the peculiar shape of the meri of the third maxillipeds.

Epistocavea mururoa sp. nov.

(Fig. 7 ; pi. 7)

Etymology. — Named in reference to the Polynesian name of the type locality. It is treated here as

a noun in apposition.

Type material. — The male 29.8 x 20.7 mm from Mururoa Island (MNHN-B22235) is designated

the holotype ; all other specimens are paratypes.

Material examined. — French Polynesia. SMCB (J. Poupin) : Society Islands : Bora Bora, Stn 275,

16°26.5'S, 151°46.2'W, trapped, 190 m, 25.06.1990 : 2 d 28.9 x 20.7, 32.9 x 23.3 mm (MNHN-B22237).

— Tuamotu Archipelago : Vanavana, Stn 331, 20°45.7'S, 139°10.TW, trapped, 240 m, 28.10.1990 : 2 9 32.1

x 22.3,30.0 x 19.7 mm (MNHN-B22236). Mururoa, 21°46.9'S, 138°55.4'W, trapped, 210 m, 30.11.1989:

1 9 32.0 x 22.8 mm (MNHN-B22234). Mururoa, Stn 222, 21°51.1'S, 138°58.7'W, trapped, 100 m,

15.05.1990 : 1 d 29.8 x 20.7 mm (MNHN-B22235). — Austral Islands : Rurutu, Stn 337, 22°28.6'S,

151°21.8'W, trapped, 125 m, 27.11.1990 : 1 ? 33.8 x 23.4 ; 4 d 35.6 x 25.3, 38.0 x 27.1, 37.5 x 26.0,

38.3 x 26.6 mm (MNHN-B22239). Ibid. 1 ? 35.5 x 24.6; 2 d 32.4 x 23.3, 41.9 x 28.5 mm (USNM).

Ibid. 1 ? 32.6 x 22.6; 2 d 38.2 x 27.4, 39.6 x 27.5 mm (QM). Tubai, Stn 349, 23°20.7'S, 149°31.9'W,

trapped, 135 m, 5.12.1990 : 1 d 30.1 x 20.9 mm (MNHN-B22238). Raevavae, Stn 346, 23°50.6'S,

147°42.5'W, trapped, 100 m, 3.12.1990 : 1 d 34.2 x 23.9 mm (MNHN-B22233).

— 524 —

Fig. 7. — Epistocavea mururoa gen. nov., sp. nov. Holotype MNHN-B22235, Mururoa, Tuamotu Archipelago. A,

frontal view ; B, abdomen ; C, third maxilliped ; D, second gonopod ; E, F, first gonopod ; G, sternum and

abdomen.

Description

Carapace transversely ovoid, c. 1.4-1.45 times broader than long. Fronto-orbital width c.

0.66-0.68 times carapace length. Carapace slightly convex in both directions, particularly over

anterior third longitudinally. Regions moderately defined; IF and 2F fused; 1M separated

from 2F ; 2M partially longitudinally divided, internal branch of 2M fused with 1M, outer

- 525 —

branch also partially divided anteriorly ; 2M separated from 3M ; 4M indistinct ; 1R and 2R

fused, separated from 3R by shallow furrow ; IP and 2P shallowly defined ; 2L and 3L fused.

Anterolateral margins regularly convex ; slightly cristate ; divided into 4 teeth. Anterolateral

teeth triangular, bluntly acute, second tooth the largest, followed by third ; first and fourth

slightly smaller ; first tooth adjacent to lateral edge of orbit but well separated ; anterolateral

margins continuing in an arc below orbit, meeting the anterolateral corner of the buccal frame,

continuous with concave lower margin of epistome ; epistome projecting forward as a fine rim ;

meri of third maxillipeds sharply angled to fit against epistome, thus completely sealing buccal

cavity ; forming, with maxillipeds in place, a continuous convex arc with anterolateral

margins ; whole region across front from below orbits deeply excavated, and surface markedly

corrugated and pitted. Front c. 0.3 times carapace width ; c. 0.6 times fronto-orbital width ;

moderately projecting, medially, with V-shaped medial notch, laterally oblique, slightly

concave, lateral teeth blunt, slightly projecting ; pre-orbital granular shoulder ; lateral margins

diverging posteriorly. Posterior margin c. 0.4 times carapace width. Carapace surface

granulate, granules larger anteriorly, coalescing into irregular rows anterolaterally, especially

below orbits. Setae short, covering entire surface. Upper orbital border evenly granular ;

concave ; orbital fissures obsolete. Lower orbital border irregularly granular. Inner angle of

lower orbital border formed by a triangular tooth. Antennal flagellum small and entering

orbit ; flagellum very fine, reaching about half distance to lateral margin ; without accessory

setae. Basal antennal segment broadly in contact with front ; granular ; with small outer lobe

lying against inner tooth of orbit. Basal antennular segment triangular, excavated medially,

flagellum folding obliquely. Inter-antennular septum narrow.

Third maxilliped : merus distinctly shorter than ischium ; merus wider than long ; upper

third of merus sharply angled backwards, forming a concave shelf ; seen from antero-ventral

position merus having antero-medial margin bilobed, with outer lobe produced laterally to

form anterolateral angle. Ischium rectangular, c. 1.7 times longer than wide; inner margin

granular. Palp articulating at inner distal margin of merus ; carpus and propodus with small

ridges and projections.

Chelipeds markedly unequal, right usually larger but sometimes left ; large and robust,

smaller chela of similar form but less massive than large chela ; merus with posterior border

bearing large granules ; otherwise surfaces covered with small granules, but margins unarmed ;

carpus with a broad tooth at inner angle ; a tooth present on inner face of carpus slightly below

inner angle ; outer margin granular, granules on upper surface coalescing to form deep

corrugations and pits. Outer surface of palm sparsely granular, smooth ventrally, becoming

progressively more granular towards dorsal margin ; upper surface with two longitudinal rows

of fused granules connected to each other and to posterior margin by meshwork of short

granular ridges ; inner proximal edge moderately produced as rounded lobe. Outer surface of

palm naked. Inner surface of palm microscopically granular, with a few larger granules

ventro-proximally. Immovable finger with ventral ridge ; moderately long. Length cutting edge

c. 0.37-0.41 times length propodus (major chela). Ventral border of chela concave at base of

fixed finger. Dorsal surface of dactyl smooth, rounded. Fingers pointed ; a narrow gape

between cutting margins.

Walking legs of medium length ; flattened ; moderately slender ; second pair the longest,

c. 1.25 times maximum carapace width. Merus of third leg c. 3.1-3.3 times as long as wide.

Carpus c. 2.2-2A times as long as wide. Propodus c. 1.5-1.7 times as long as wide. Dactyli c.

— 526 —

1.7-1.8 times length of propodus. Dactyli stout, straight, and flattened ; terminating in an acute

chitinous tip. Merus of anterior margin with a small sub-distal shoulder ; anterior margin

unarmed terminally. Carpus with accessory carinae on upper surface. All segments generally

smooth ; setae short, almost covering entire surface ; longer setae fringing margins.

Male abdomen relatively narrow ; five free segments ; third to fifth fused ; third segment

the widest. First segment c. 0.75 times width third segment. Segments three-five tapering.

Segment six c. 1.5-1.6 times wider than long. Telson c. 0.7 times longer than wide; bluntly

pointed.

Gonopods : G1 medium length ; slender ; curved. Setae present ; short ; arranged as on

figure. G2 short ; evenly curved ; tip short, recurved.

Sternum relatively broad ; segments 3 and 4 fused, but suture line evident except medially.

Distribution. - Only known from French Polynesia, from the Society Islands, 16°26.5'S,

151°46.2'W, to the Austral Islands, 23°50.6'S, 147°42.5'W. Bathymetric range : 100-240 m.

Medaeus grandis sp. nov.

(Fig. 8 ; pi. 8)

Etymology. — Named in reference to its very large size compared to other known species of

Medaeus.

Type material. — The large male 37.2 x 24.6 (MNHN-B22218) is designated as holotype. The other

two specimens are paratypes.

Material examined. — French Polynesia. SMCB (J. Poupin) : Tuamotu Archipelago : Mururoa,

21°46.9'S, 138°55.4'W, trapped, 210 m, 30.11.1989 : 1 J 37.2 x 24.6 mm (MNHN-B22218). Ibid. 1 $ 33.4

x 22.3 mm (MNHN-B22219). Hao, St 246, 18°04.5'S, 141°01.6'W, trapped, 90 m, 2.06.1990 : 1 $ 21.2

x 14.7 mm (MNHN-B22220).

Description

Carapace transversely ovoid; c. 1.5 times broader than long (1.44 in female). Fronto-

orbital width c. 0.7 times carapace length (0.76 in female). Carapace convex in both directions,

especially longitudinally over anterior third, but only slightly from side to side. Regions well

defined, elevated, separated by strong furrows ; 1 F and 2F fused, slightly elevated ; 1M

separated from 2M ; 2M completely divided longitudinally and outer lobe partially divided

anteriorly ; 3M slightly bilobed posteriorly ; 4M very strongly elevated and separated from

3M ; all anterolateral regions defined, 2L divided into 3 equal-sized lobes, 5L and 6L divided

in halves by horizontal and oblique furrows, respectively, 5L not completely ; 1R and 2R not

separated, divided from 3R by a broad oblique furrow; IP with strongly elevated transverse

ridge, only slightly narrower than posterior margin, with 2 very short, irregular granular crests

above and below, slightly beyond its lateral edge ; 2P with a transverse granular row, elevated

laterally, barely distinguishable medially ; posterior margin costate, with a raised granular rim ;

— 527 —

Fig. 8. — Medaeus grandis sp. nov. Holotype <J, MNHN-B22218, Mururoa, Tuamotu Archipelago. A, frontal view;

B, third maxilliped ; C, abdomen ; D, sternum and abdomen ; E, F, first gonopod ; G, second gonopod.

posterolateral margins swollen and slightly convex at 1R/2R, then straight. Anterolateral

margins regularly convex ; with five teeth behind the exorbital angle ; margins granular, first

tooth the smallest, well separated from orbit, and situated lateral to, and well below, level of

orbit seen in frontal view ; anterior to first tooth an ill-defined oblique granular row continuing

— 528 —

on towards anterolateral corner of buccal frame ; second to fifth teeth increasing in size ;

second tooth relatively close to first tooth ; all teeth triangular, bluntly pointed ; greatest

carapace width (across fifth teeth). Front c. 0.26-0.31 times carapace width; 0.7 times

fronto-orbital width (0.76 on female) ; not deflexed and moderately projecting, granular ;

slightly more prominent, narrow medial projections separated by V-shaped notch ; laterally

receding, more-or-less straight ; with more prominent blunt lateral projections ; pre-orbital

bluntly granular shoulder. Posterior margin c. 0.33-0.35 times carapace width (0.4 in female).

Carapace surface granulate except in smooth furrows separating regions ; almost entirely

covered in very short setae which are lower than the granules. Upper orbital border concave,

evenly granular ; pair of shallow smooth furrows marking presence of broad truncate lateral

tooth. Lower orbital border of inner angle formed by a triangular, granular, bluntly pointed

tooth ; laterally with a second smaller blunt granular lobe ; with V-shaped notch laterally.

Antennal flagellum small and entering orbit, fine, without accessory setae, reaching beyond

orbit about half distance to first anterolateral tooth. Basal antennal segment broadly in contact

with front, granular, rectangular, unarmed. Basal antennular segment with raised granular

rim across upper and lateral margins, palp folding slightly obliquely. Inter-antennular

septum moderately narrow, margins convex basally, outer edge of floor of antennular fossa,

granular, more-or-less flat, slightly convex medially ; lower margin of epistome projecting as

thin rim.

Third maxilliped : merus distinctly shorter than ischium, width of merus c. 0.7 times

length ; antero-external angle produced, slightly rounded ; c. 0.5 times length of ischium.

Ischium sub-rectangular c. 1.7 times longer than wide.

Chelipeds markedly unequal ; large and robust, left cheliped the larger on all present

specimens ; minor cheliped of similar form but with longer, more slender fingers. Merus with

posterior border tuberculate ; lower border granulate ; anterior border tuberculate, slightly

smaller tubercles than posterior border. Carpus with a broad tooth at inner angle ; inner

margin sharply granular ; a tubercle with a row of sharp granules proximal to it present on

inner face of carpus slightly below inner angle ; outer margin granular and rugose. Outer

surface of palm coarsely granular and coarsely rugose dorsally. Outer surface of palm without

setae. Inner surface of palm granular. Immovable finger short (on major chela), with ventral

ridge, and second longitudinal groove below cutting margin. Length of cutting edge c. 0.34

times length of propodus. Ventral border of chela slightly concave at base of fixed finger.

Dorsal surface of dactyl minutely granular ; dactyl very broad, bearing 3 longitudinal grooves

on outer face, running most of length. Fingers pointed, recurved ; cutting margins of both

fingers with 3 large, molariform teeth over proximal two-thirds ; without a noticeable gape

between the cutting margins.

Walking legs of medium length ; compressed ; slender ; first three pairs all of similar

length, c. 1.1 times maximum carapace width. Merus of third leg c. 3.8-4.1 times as long as

wide. Carpus c. 2.3-2.4 times as long as wide. Propodus c. 2-2.1 times as long as wide. Dactyli

c. 1.3 times length of propodus. Dactyli slender, straight, and flattened ; terminating in an acute

chitinous tip. Merus of anterior margin terminating in a blunt tooth. Carpus with accessory

carinae on upper surface. All segments granular, with a more prominent row of tubercles along

upper margins of meri, and on antero-ventral borders, particularly of first two pairs ; short

setae cover entire surface, as on carapace, shorter than granules, longer on inside margins of

dactyli.

— 529

Male abdomen relatively narrow ; five free segments ; third to fifth fused ; third segment

the widest. First segment c. 0.75 times width third segment. Segments three-five tapering.

Segment six not elongated, 1.7 times wider than long. Telson c. 0.7-0.75 times longer than

wide ; evenly rounded.

Gonopods : G1 medium length, moderately stout, curved, tip finely pointed ; bearing row

of long setae distally on dorsal margin behind apex. G2 moderately long, evenly curved, tip

short, recurved.

Sternum relatively broad, granular, covered in very fine, very short setae.

Distribution. — Known only from French Polynesia. Bathymetric range : 90-210 m.

Remarks

This species belongs without doubt in Medaeus according to the modem diagnosis given

by Guinot (1967). Comparisons were also made with specimens of the other two species

presently included in the genus — Medaeus ornatus Dana, 1852, and M. elegans A. Milne

Edwards, 1867 — housed in the Muséum National d’Histoire Naturelle in Paris, and previously

reported on by Guinot (1967). Medaeus ornatus is much spinier than M. grandis and, in

particular, the fourth anterolateral teeth are the most prominent and form the greatest

carapace breadth ; the anterolateral teeth are also, in general, more upturned ; the median and

lateral lobes of the front are much more projecting ; the margins of the leg segments are much

spinier ; the dorsal surface of the palm of the cheliped has two rows of large granular lobes,

and the dorsal margin of the dactyl has sharp tubercles. On M. grandis the palm of the chela

lacks large lobules and the dactyl is only microscopically granular. There are also differences

in male abdomen and pleopod shapes (Guinot, 1967, fig. 39).

In general form M. grandis looks more like M. elegans but can be separated by having

longer, slimmer legs ; a less medially protruding frontal margin ; a more granular carapace

surface ; region 2L divided into three parts ; margins of each of the fused male abdominal

segments 3-5 evenly tapering, not concave as in M. elegans, and by the shape of the male

pleopod (Guinot, 1967, fig. 38).

Actaeinae Alcock, 1898

MERACTAEA Serène, 1984

Meractaea Serène, 1984 : 103.

Type species. — Meractaea brucei Serène, 1984, by original designation.

Diagnosis. — Carapace wider than long and transversely oval. Frontal border four-lobed with a

rounded medial groove. Anterolateral borders of carapace regularly convex, bearing four teeth or lobes

behind rounded exorbital lobe, tooth N being the largest. Dorsal surface of carapace longitudinally convex

over anterior third but flattened from side to side ; completely lacking setae. Regions well separated by

— 530 —

smooth grooves bearing bulging granules of irregular size, some joined but most separated. Third

maxilliped with bulging, rounded tubercle on outer medial face of merus. Chelipeds subequal ; same

ornamentation as dorsal carapace regions. Fingers of chelipeds distally pointed ; crossing when closed.

Walking legs narrow, smooth and naked except for some isolated long setae and rows of short setae on

ventral borders of propodi and dactyli. First and second male pleopods are of same type as those of the

Actaeinae. (Modified after Serène, 1984.)

Remarks

Meractaea Serène, 1984, has until now only contained the single species, M. brucei Serène,

1984, from Kenya, East Africa. The discovery of the present new species justifies its generic

rank and marks it as a widespread Indo-West Pacific genus. The two species are remarkably

similar, indeed, the presence of a large bulging tubercle on the outer face of the merus of the

third maxilliped which was considered by Serène (1984) to probably be a specific character, is

also present on Meractaea tafai sp. nov. and I have therefore included it in the generic

diagnosis.

Meractaea and Rata gen nov. (described later) are unique among the Actaeinae in having

relatively long, slender walking legs. Serène (1984) felt that only Forestia approached

Meractaea in this regard, but even on Forestia the legs are closer to typical genera of Actaeinae

than to either Meractaea or Rata. Meractaea is immediately identifiable by the characteristic

pattern of carapace regions ; the bulging tubercles on carapace and pereiopods ; and the lack

of dorsal carapace setae.

Meractaea tafai sp. nov.

(Fig. 9 ; pi. 9)

Etymology. — Named in reference to a legendary Tahitian hero who was reputed to have red skin.

Type material. — The larger male (23.9 x 15.7 mm) is designated holotype ; the other specimens

are paratypes.

Material examined. — French Polynesia. SMCB (J.Poupin) : Tuamotu Archipelago : Stn 240,

Acteons Maria, 22°01.8'S, 136°12.4'W, trapped, 150 m, 30.05.1990 : 1 d 23.9 x 15.7 mm (MNHN-

B22216). Ibid. 1 $ 14.0 x 9.0 mm; 2? 32.0 x 21.0, 30.3 x 19.6 mm (MNHN-B22224).

Description

Carapace ovoid, c. 1.5-1.6 times broader than long. Fronto-orbital width c. 0.8 times

carapace length. Carapace convex anteriorly, flat from side to side across postero-branchial

regions. Regions distinct and well separated by narrow furrows, each taking the form of

rounded bulges of various shapes, with uneven surfaces ; IF and 2F fused, rising abruptly from

just behind frontal margin ; 1M separated from 2F ; 1M separated from 2M ; 2M separated

from 3M ; 2M longitudinally divided ; 3M divided basally into three parts, a narrow anterior

projection and two basal rounded lobes ; 4M consisting of a row of 3 rounded tubercles, medial

— 531

mmm '?o

Fig. 9. — Meractaea tafai gen. nov., sp. nov. Holotype S, MNHN-B22216, Acteons Maria, Tuamotu Archipelago. A,

frontal view ; B, third maxilliped ; C, abdomen ; D, sternum and abdomen ; E, F, first gonopod ; G, second

gonopod.

one largest ; IP divided longitudinally, with small rounded medial tubercle posteriorly ; 2P with

two strong transverse crests, the anterior one divided medially ; postero-branchial regions with

rounded granules and shallow furrows. Anterolateral margins regularly convex ; consisting of

5 evenly separated teeth including bluntly rounded orbital lobe ; second tooth much smaller,

partially divided into 2 rounded granules ; third tooth longest, broad, bluntly pointed ; fourth

tooth also large, narrower ; fifth tooth smaller, pointing postero-laterally. Front c. 0.3 times

carapace width ; c. 0.55 times fronto-orbital width ; strongly sinuous, frontal margin with pair

of narrow projecting, medial lobes and pair of equally projecting, but broad, lateral lobes ;

lateral angles rounded, similarly projecting ; upper orbital border framed by three large

rounded lobes, medial one smaller, lateral one equivalent to region 1L ; lower orbital border

— 532 —

concave medially, with large rounded inner lobe. Posterior margin c. 0.35 times carapace width.

Antennal flagellum small and entering orbit. Basal antennal segment just touching front ;

unarmed except for swollen, rounded medial tubercle. Basal antennular segment normal,

flagellum folding almost transversely. Inter-antennular septum narrow.

Third maxilliped : merus distinctly shorter than ischium, c. 0.85 times wider than long,

with a single large bulbous tubercle on outer face ; 0.6-0.65 times length of ischium. Ischium

rectangular, c. 1.5 times longer than wide. Palp articulating at inner distal margin of merus.

Chelipeds subequal ; robust, moderately large ; height of palm c. 0.5 times length of palm

including fixed finger. Merus with posterior border granulate ; with larger small, sharp granule

subdistally ; armed with rounded tubercle terminally ; lower border granulate ; anterior border

microscopically granular. Carpus with inner angle produced as a broad rounded tubercle ;

upper surface of carpus covered with large, rounded, well-separated tubercles ; a tooth present

on inner face of carpus slightly below inner angle. Outer surface of palm coarsely granular,

granules arranged in 7 major rows ; uppermost two rows formed by very large, swollen,

rounded tubercles as on carpus and carapace ; ventral two rows continuing onto fixed finger

as strong, more-or-less smooth ridges, reaching to tip. Outer surface of palm naked. Inner

surface of palm granular, with larger coarse granules medially ; bearing long setae below upper

margin ; brown colouring of fixed finger extending proximally to about middle of palm as large

rounded plume, on outer face colouring ending obliquely and not extending far onto palm.

Length cutting edge c. 0.35 times length propodus. Ventral border of chela concave at base of

fixed finger. Dorsal surface of dactyl microscopically granular ; with large bulbous tubercle

basally. Fingers pointed ; without a noticeable gape between the cutting margins.

Walking legs relatively long; flattened; slender; second pair the longest, c. 1.4 times

maximum carapace width. Merus of third leg c. 3-3.2 times as long as wide. Carpus c. 2.5-2.6

times as long as wide. Propodus c. 2-2.1 times as long as wide. Dactyli c. 1.3-1.4 times length

of propodus. Dactyli straight ; terminating in an acute chitinous recurved tip. Merus anterior

margin unarmed terminally, upper margin armed with a row of small, semi-acute, distally

pointing tubercles ; lower margin unarmed. Carpus with accessory carinae on upper surface.

Upper margins of leg segments of carpus and propodus bearing row of larger blunt tubercles,

appearing coarsely serrated ; otherwise surface of segments microscopically granular. Legs with

scattered setae, and with fringe of very short setae on ventral margins of propodi and dactyli.

Male abdomen relatively narrow ; five free segments ; third to fifth fused. First segment

broad, subequal in breadth to third. Segments three-five tapering. Segment six c. 1.1 times

wider than long. Telson longer than sixth segment ; 0.95 times longer than wide ; evenly

rounded.

Gonopods : G1 long, slender, curved ; long, feathered, setae present on distal dorsal

margin. G2 short, evenly curved ; tip short, recurved.

Sternum relatively broad ; telson reaching c. half length of fused sternites 3 and 4 ; female

abdomen relatively narrow, not covering sternum.

Colouration. — Furrows between regions, over anterior third of carapace, coloured dark

reddish purple, becoming pale greenish blue posteriorly ; upper surfaces of bulbous regions

orange. Upper surfaces of chelipeds coloured like carapace ; outer faces of palms becoming

off-white ventrally. Each leg with an orange band proximally and distally on merus, and a

medial band on carpus, propodus, and dactylus.

— 533 —

Distribution. — Known only from the type locality in French Polynesia.

Remarks. — Meractaea tafai sp. nov. is separable from the only other species in the genus,

M. brucei, by several points. 1. The male first pleopod has the tip more truncated in M. tafai ;

and the setation also differs with M. tafai having more long feathered setae and lacking the

short, more proximal bristles of M. brucei. 2. The dorsal carapace regions of M. tafai are even

more strongly bulging and sharply defined, and although their surfaces are uneven, they are not

granular as in M. brucei. 3. The upper margins of the meri of the walking legs are more coarsely

granular in M. tafai.

RATA gen. nov.

Etymology. — Named after a mythological Polynesian nautical hero, who was a grandson of Tafai.

Gender is neuter.

Type species. — Rata tuamotense sp. nov., here designated.

Diagnosis. — Carapace transversely ovoid, 1.4-1.5 times broader than long. Regions well defined.

Anterolateral margins regularly convex ; with four teeth behind the exorbital angle ; a more-or-less distinct

row of granules below first tooth running from second tooth to just short of lateral edge of orbit.

Posterolateral margins convergent, not sharply defined, moderately cut-away to receive meri of last pair

of legs. Front c. one-third carapace width ; 0.5-0.6 times fronto-orbital width ; not projecting, with a pair

of broad lateral lobes and a pair of blunt tubercular projections medially. Upper orbital border concave ;

lower orbital border with inner angle formed by a triangular tooth, with V-shaped notch laterally.

Antennal flagellum small and entering orbit ; basal antennal segment just touching front. Basal antennular

segment moderately broad, flagellum folds almost transversely, first segment of flagellum relatively slender

and elongated. Inter-antennular septum moderately narrow, with a longitudinal furrow. Third maxilliped

with merus distinctly shorter than ischium ; merus wider than long, antero-external angle produced.

Chelipeds subequal ; large and robust ; fingers pointed. Walking legs relatively long ; compressed ;

moderately slender ; dactyli slender and straight. Male abdomen relatively narrow ; five free segments ;

third to fifth fused ; first segment subequal in width to third, narrow. Gonopods : G1 long, slender, curved,

reaching to suture between stemites 4 and 5 ; G2 short, evenly curved ; tip short, reflexed, pointed.

Remarks

Rata appears most closely related, amongst the Actaeinae, to Forestia Guinot, 1976. Only

Forestia and Meractaea Serène, 1984, of all the Actaeinae genera, have the walking legs

relatively elongated. Meractaea as discussed elsewhere in this paper is extremely unusual in

many ways and not a close relative of Forestia or Rata. Forestia was originally erected to accept

three species, F. depressa (White, 1847), F. scabra (Odhner, 1925) and F. abrolhensis

(Montgomery, 1931). Subsequently, F. pascua Garth, 1985, has been described from Easter

Island, but is known only from the single female type specimen.

Rata differs from Forestia in many characteristics.

1. The structure of the antennules and interantennular septum differ. In Forestia the first

segment of the palp of the antennule is short and swollen and folds obliquely, whereas in Rata it is

slender and elongated and folds almost transversely. The interantennular septum in Forestia is

very narrow and sharp but in Rata it is noticeably wider and bears a vertical medial furrow.

— 534

2. The width of the front in Forestia (measured from the outer edge of the lateral teeth)

is about one fourth of the carapace breadth. In Rata the frontal width is about one-third of

the carapace breadth.

3. The frontal margin of Forestia is formed by two large convex lobes which are strongly

produced and moderately depressed partly hiding the antennules in frontal view. In Rata the

frontal margin is not at all produced, there is a small blunt tooth on either side of the medial

line followed by slightly convex lateral lobes, and the antennules are not hidden in frontal view.

4. The walking legs in Rata are even more elongated and slender, and, in particular, the

dactyli are very long and slender.

5. In Forestia the first segment of the male abdomen is relatively long, about the same

length as segment 2, and flattened. In Rata the first segment is very narrow and not flattened.

6. In Rata the anteroexternal angle of the merus of the third maxilliped is strongly

produced laterally, whereas in Forestia it is more nearly quadrate.

I have examined all the Forestia species except F. pascua (Garth). F. pascua appears

somewhat different from the other three species and close to Rata tuamotense sp. nov. but

unfortunately the description is not sufficient to be certain if it is really a true Forestia. The

shape of the carapace, the wide, non-protruding front, the carapace regions and granulation,

all strongly suggest the appearance of Rata. The antero-external angle of the third maxilliped

is produced a little more than in typical Forestia species, but not as much as in Rata

tuamotense. A careful examination of the frontal region is necessary to be sure of its correct

generic placement. The two species can be easily separated because F. pascua has broader, more

prominent anterolateral teeth, and the carapace region 2M is completely subdivided.

The differences between Rata and some of the genera of Xanthinae are not very great, and

its placement in the Actaeinae is largely on subjective criteria, and on an assessment of its

closest relatives. Guinot (1976) in an excellent study on the Actaeinae cleared up many

problems but did not provide an assessment of the characters that are unique to the subfamily.

A clear definition of the Actaeinae is still needed.

Rata tuamotense sp. nov.

(Fig. 10 ; pi. 10)

Etymology. — The name refers to the Island group in French Polynesia where the holotype was

collected.

Type material. — The male of 20.9 x 14.5 mm (MNHN-B22231), from Fangataufa, is designated

the holotype. All remaining material is paratypic.

Material examined. — French Polynesia SMCB (J. Poupin) : Marquises Islands : Tahuata, Stn 300,

9°54.5'S, 139°07.9'W, trapped, 190 m, 1.09.1990 : 1 ? 19.6 x 14.0 mm (USNM). — Tuamotu Archipelago :

Tematangi, Stn 328, 21°40.6'S, 140°30.5'W, trapped, 270 m, 27.10.1990 : 1 <3 29.6 x 20.1 mm

(MNHN-B22230). Fangataufa, Stn 231, 22°12.0'S, 138°45.9'W, trapped, 270 m, 21.05.1990 : 1 3 1 20.9 x

14.5 mm (MNHN-B22231). Fangataufa, Stn 234, 22°15.0'S, 138°46.0'W, trapped, 250 m, 22.05.1990 : 1

ovig. $ 16.8 x 11.8 mm (MNHN-B22232)

Description

Carapace transversely ovoid, c. 1.4-1.47 times broader than long. Fronto-orbital width c.

0.82-0.86 times carapace length. Carapace convex anteriorly, flat from side to side across

postero-branchial regions. Regions well defined, separated by broad, deep smooth grooves ; IF

and 2F not separated ; 1M distinct, anterior margin laterally oblique ; a small raised granular

patch lateral to 1M and above middle of 2M ; 2M distinct, longitudinally divided for anterior

three-quarters, with raised tubercle on either side of anterior end of dividing groove, outer

branch much wider than inner branch ; 3M entire, anterior extension very narrow, reaching

nearly to middle of 1M ; 4M distinct ; broad, smooth groove posterior to raised orbital rim ;

2L and 3L fused, armed with 3 or 4 larger granular tubercles ; 4L, 5L and 6L all distinct, armed

with coarse tubercles of various size ; sub-parallel cardiac-intestinal grooves present, but

cardiac region (IP) not clearly separated from 3R anterolaterally, and cardiac and intestinal

regions not clearly separated from each other ; 2P with slightly raised, blunt ridges laterally

above posterior margin. Anterolateral margins regularly convex ; with four teeth behind the

exorbital angle ; first tooth in form of strong tubercle displaced slightly onto anterior surface ;

below first tooth surface irregularly granular with a more-or-less distinct row of granules (of

which one or two may form prominent tubercles) running from second tooth nearly to lateral

edge of orbit, level with lower orbital margin ; second tooth broadly triangular, armed with

accessory granules ; third tooth similar to second ; fourth similar but narrower ; carapace

breadth slightly greater between third anterolateral teeth than fourth ; posterolateral margins

convergent, not sharply defined, moderately cut-away to receive meri of last pair of legs. Front

c. 0.3-0.33 times carapace width ; c. 0.52-0.56 times fronto-orbital width ; strongly sinuous in

anterodorsal view ; in dorsal view not at all projecting, with a pair of broad lateral lobes and

a pair of blunt tubercular projections medially ; lateral angles also moderately produced and

armed with a few acute granules. Posterior margin c. 0.3 times carapace width in males ; 0.36

in females. Upper surface of carapace regions granular, granules unevenly sized, with larger,

rounded tubercles laterally on regions 2L-5L ; each granule bearing semi-circlet of short stiff

setae anteriorly ; setae thus forming a conspicuous covering. Upper orbital border evenly

granular ; concave ; lateral fissures fused, evident as smooth grooves interrupting margin.

Lower orbital border sinuous ; evenly granular ; inner angle formed by a triangular tooth ; with

V-shaped notch laterally. Antennal flagellum small and entering orbit, fine, just reaching to

outer edge of orbit. Basal antennal segment just touching front. Basal antennular segment

moderately broad, flagellum folds almost transversely, first segment of flagellum relatively

slender and elongated ; anterolateral margins of epistome granular, lower margin strongly

projecting, sinuous, and deeply cleft. Inter-antennular septum moderately narrow, with a

longitudinal furrow.

Third maxilliped : merus distinctly shorter than ischium ; merus wider than long, length

c. 0.7 times width ; antero-external angle produced, rounded ; c. 0.6 times length of ischium.

Ischium rectangular, length c. 1.4 times width.

Chelipeds subequal ; large and robust ; height of palm 0.55-0.6 times length including fixed

finger. Merus with posterior border granulate, with broad subdistal lobe ; lower border

minutely granulate, rounded ; anterior border minutely granulate. Carpus with inner angle

produced, bluntly rounded ; connected by an oblique granular crest to a more-or-less

produced, rounded, ventral tooth ; inner margin granular ; upper and outer surfaces covered

— 536 —

Fiü. 10. — Rata tuamotense gen. nov., sp. nov. Holotype <?, MNHN-B22231, Fangataufa, Tuamotu/Gambier

Archipelago. A, frontal view ; B, C, first gonopod ; D, third maxilliped ; E, abdomen ; F, sternum and abdomen ;

G, second gonopod.

in large, rounded, well-separated tubercles. Outer surface of palm coarsely granular, mostly

arranged in 6-7 irregular rows ; densely covered by fine, stiff setae, not obscuring surface,

longer on superior and inferior margins and around base of fingers. Inner surface of palm

minutely granular on upper half ; more coarsely behind fixed finger. Immovable finger with

ventral ridge ; moderately long ; length cutting edge c. 0.36 times length propodus. Ventral

border of chela concave at base of fixed finger. Dorsal surface of dactyl granular. Fingers

pointed ; without a noticeable gape between cutting margins.

Walking legs relatively long ; compressed ; moderately slender ; first three pairs of similar

length ; c. 1.1 times maximum carapace width. Merus of third leg c. 2.7-2.8 times as long as

wide. Carpus c. 2.2-2.3 times as long as wide. Propodus c. 1.7-1.8 times as long as wide. Dactyli

c. 1.5-1.6 times length of propodus. Dactyli slender and straight; terminating in an acute,

— 537 —

chitinous, recurved tip. Merus bearing small sharp granules along superior border ; a sub-distal

tubercle ; terminating in an acute tooth ; blunt granules along inferior border. Carpus with a

longitudinal sulcus on upper surface bordered by two rows of sharp tubercles. Propodus also

with two rows of smaller, but relatively coarse, sharp tubercles. All segments covered with

short setae, and fringed with longer stiff setae.

Male abdomen relatively narrow ; five free segments ; third to fifth fused ; first segment

subequal in width to third, narrow. Segments three-five tapering. Segment six moderately

elongated, c. 1.1 times wider than long. Telson about as long as wide; triangular, rounded

apically.

Gonopods : G1 long, reaching to suture between sternites 4 and 5 ; slender ; curved ; long,

feathered setae on dorsal margin near tip ; small, conical setae along dorsal margin over distal

half, and on ventral margin near tip ; tip hollowed ; gonopore subterminal ; bluntly pointed (as

in figure) or more acute in large male. G2 short, evenly curved ; tip short, reflexed, pointed.

Colouration. — In life, background colour porcelain white with orange highlighting.

Orange particularly strong : on frontal region and 1M ; towards anterior parts of other

regions ; on anterolateral margins ; on distal border of carpus behind articulation with palm ;

on superior inner margin of palm, and on the base of dactyl. Fingers blackened, but black

colouration of fixed finger not extending backwards onto palm.

Distribution. — Known only from French Polynesia, between the Marquises Islands

(9°54'S) and Tuamotu/Gambier Archipelago (22°15'S). Bathymetric range : 190-270 m.

Zosiminae Alcock, 1898

Lophozozymus bertonciniae Guinot and Richer de Forges, 1981

(PI. 11)

Lophozozymus bertonciniae Guinot and Richer de Forges, 1981a : 1123-1127, fig. 2 A-D, pi. I, 5, 5a.

Material examined. — French Polynesia. SMCB (J. Poupin) : Marquises Islands : Tahuata, Stn 297,

9°54.3'S, 139°07.3'W, 100 m, trapped, 31.08.1990 : 1 ? 56.1 x 34.9, 1 <? 61.0 x 38.5 mm (MNHN).

Hiva-Oa, 9°49.7'S, 139°09.1'W, 100 m, September 1989 : 2$ 58.1 x 36.2, 60.0 x 37.1, 1 $ 64.7 x 41.0

mm (QM W8030). — Tuamotu Archipelago : Tenarunga, 21°21.0'S, 136°32.0'W, 160 m, trapped,

19.11.1989 : 1 $ 81.5 x 48.3 mm (MNHN). Mururoa, Stn 228, 21°51.9'S, 139°01.6'W, 200 m, trapped,

19.05.1990 : 1 ? 72.2 x 45.8, 1 J 78.0 x 47.4 mm (USNM). — Austral Islands : Maria, Stn 420, 21°47.3'S,

154°42.4'W, trapped, 7.08.1991 : 1 ? 90.8 x 57.0 mm (MNHN). — New Caledonia. Collected by Mr.

Barro : passe de Boulan, 200 m, 4.06.1978 : 1 d 65.1 x 39.5 mm (MNHN).

Remarks

Lophozozymus bertonciniae Guinot and Richer de Forges, 1981, was well separated from

most of its congenors as part of the original description. It seems that it is most closely related

to L. superbus (Dana, 1852) and some confusion has persisted in separating the two species.

— 538 —

I have examined two specimens that can be attributed to L. superbus, one immature female

(30.7 x 18.7 mm) in the MNHN previously mentioned by Guinot (1977) from the type area

(Tuamotu Arch.), and one larger male (40.7 x 24.8 mm) from Wreck Reef, southern Coral

Sea, in the collections of the Queensland Museum. A neotype will need to be erected to firmly

establish the identity of L. superbus as Dana’s type specimen can be presumed destroyed as it

has not been listed amongst Dana’s surviving material. This action will be deferred awaiting

additional material from the Tuamotus. Characters which can be used to separate the two

species are given in the following. 1. The male abdomens differ in shape ; in bertonciniae the

fused segments 3-5 have the sutures still quite strongly marked and the lateral borders of each

original segment are produced laterally at their proximal ends ; whereas in superbus the sutures

are hardly evident and the lateral margins are almost evenly tapering. 2. The inner lower orbital

tooth in bertonciniae is somewhat flared outwards and projects strongly beyond the outer distal

angle of the basal antennal segment, which is subquadrate ; in superbus, the inner lower orbital

tooth is not flared outwards and does not project very far past the outer distal angle of the

basal antennal segment, which itself is markedly produced and lies against the inner orbital

tooth. 3. In bertonciniae the first anterolateral tooth is sharply cristate, and obliquely projecting

upwards, with its ventral surface flat ; in superbus, the tooth is slightly deflexed ventrally, with

its edge rolled in such a way that it overhangs and forms a groove below it. These differences

also apply in less marked degree to the second anterolateral tooth. 4. In superbus the dorsal

carapace surface is evenly covered with many punctations, each with a small tuft of short setae ;

in bertonciniae the upper surfaces of the regions mostly lack punctations, and are smooth and

glabrous.

Lophozozymus superbus is apparently a shallow water coral reef species, but L. bertonciniae

seems to prefer deeper water with all records between 100 and 200 m.

Distribution. — Southern Pacific Ocean, from New Caledonia (type locality) to French

Polynesia. These records mark a major range extension. Bathymetric range : 100-200 m.

Liomerinae Sakai, 1976

MERIOLA gen. nov.

Etymology. — Formed by re-arranging the letters of Liomera. Gender is feminine.

Type species. — Meriola rufomaculata sp. nov., here designated.

Diagnosis. — Carapace transversely ovoid ; c. 1.5-1.6 times broader than long. Regions moderately

defined ; orbital margin swollen. Anterolateral margins regularly convex ; with four teeth behind the

exorbital angle ; margins bluntly crested. Front c. one-quarter carapace width ; moderately projecting ;

bilobed ; lateral angles bluntly prominent. Posterior margin c. 0.4 times carapace width. Upper orbital

border concave. Basal antennal segment just touching front ; flagellum small and entering orbit. Basal

antennular segment moderately broad, palp folding almost transversely. Inter-antennular septum narrow.

Merus of third maxilliped wider than long, distinctly shorter than ischium. Chelipeds large and robust ;

ventral border of chela concave at base of fixed finger ; fingers spooned ; a narrow gape between cutting

— 539 —

margins on male. Walking legs relatively long ; compressed ; slender ; all four pairs of similar length,

dactyli straight and flattened ; terminating in an acute, chitinous tip ; anterior margin of merus unarmed

terminally. Male abdomen of five free segments ; third to fifth fused. Male first gonopod long, moderately

stout, curved ; tip shaped like “ swans head Long setae present on dorsal margin and continuing along

lower edge of hollowed tip. Sternum relatively broad.

Remarks

Meriola is considered here to contain two species, the type M. rufomaculata sp. nov., and

M. acutidens (Sakai, 1969). M. acutidens was originally described as a Neoliomera by Sakai,

but was clearly aberrant within that genus. Serene (1977) transfered it to Liomera ( Bruciana ),

his new subgenus, as it seemed to him most closely related to Liomera pediger Alcock, 1898,

which he had made the type for Bruciana.

The specimens of Liomera ( Bruciana ) pediger at the MNHN, Paris, identified by Serene,

were compared with Meriola rufomaculata, and they are clearly not congeneric. I, like Serene,

have also not examined material of Sakai’s acutidens, but the similarities between it and the

present new species are striking. These include the shape and long length of the walking legs ;

the degree and pattern of regionation ; and the shape of the carapace which has relatively very

long posterolateral margins that are not as sharply oblique as is typical of Liomera and

Neoliomera. Within Liomera and Neoliomera the pattern of regions and their degree of

development varies considerably, but the very long, thin legs and the shape of the carapace are

more than enough to exclude the species here placed into Meriola.

The subgenus Bruciana as characterised by Liomera ( Bruciana ) pediger is of a much more

typical Liomera appearance. It differs from Meriola in a number of features : 1, the carapace

regions are all strongly and clearly defined ; 2, the walking legs, while being longer than a

typical Liomera, are still quite short, have the meri convex, and are quite different from the very

long, slender legs of Meriola ; 3, the first anterolateral tooth is clearly marked and separate

from the orbit ; 4, the shape of the epistome, antennae and antennules is different. In L. pediger

the basal segment of the antenna is relatively elongated and lies very obliquely (c. 45°), forming

the outer half of the floor of the antennular fossa ; and in conjunction with this the epistome

is unusually narrow. The basal antennal segment of Meriola rufomaculata is more usual in

form, being quite short and only slightly oblique, so that the epistome forms most of the floor

of the antennular fossa (compare figs 11 A and 11 I).

The taxonomic position of Meriola is not completely clear. It largely satisfies the definition

of the Liomerinae given in the key of Serene (1984) although none of the characters is

exclusively definitive for the subfamily. In its general shape and conformation of the front it

shows similarities with some members of the Xanthinae, in particular Xanthias, but the

ungulate tips of the fingers exclude it from almost all genera of Xanthinae except for Leptodius

and Macromedaeus, neither of which it resembles at all. Until a more rigorous examination of

subfamilial relationships is undertaken it is placed in the Liomerinae.

— 540 —

Meriola rufomaculata sp. nov.

(Fig. 11A-H; pi. 12)

Etymology. — The name refers to the pattern of large red patches on the dorsal surface of the

carapace.

Type material. — The male is designated the holotype, and the female a paratype.

Material examined. — French Polynesia. SMCB (J. Poupin) : Tuamotu Archipelago : Vanavana, Stn

331, 20°45.7'S, 139°10.1'W, trapped, 240 m, 28.10.1990 : 1 $ 32.0 x 20.4 mm (MNHN-B22223).

Fangataufa, Stn 231, 22°12.0'S, 138°45.9'W, trapped, 270 m, 21.05.1990 : 1 ? 31.8 x 20.3 mm

(MNHN-B22222)

Description

Carapace transversely ovoid ; c. 1.57 times broader than long. Fronto-orbital width c. 0.7

times carapace length. Carapace evenly convex longitudinally, flat from side to side. Regions

moderately defined ; IF marked by swollen rounded ridge parallel to frontal margin ; 2F not

distinct ; 1M moderately swollen and separated by broad, shallow groove from inner branch

of 2M ; 2M partially longitudinally divided anteriorly by broad, shallow groove, outer branch

of 2M wider than inner branch ; 2M separated from 3M ; orbital margin swollen and separated

from posterior regions by strong groove ; IL, 2L and 3L fused, delimited posteriorly by strong,

oblique, slightly concave groove originating on lateral margin between second and third

anterolateral teeth ; a similar, much shorter groove between third and fourth teeth ; cardiac and

intestinal regions defined by diffused grooves. Anterolateral margins regularly convex ; with

four teeth behind the exorbital angle ; margins bluntly crested ; first tooth lateral to orbit, well

separated, connected by straight, slightly oblique margin very poorly defined in frontal view ;

ill defined, granular, slightly flattened area running from first tooth obliquely below orbit ;

second tooth broad, rounded ; third tooth narrower, slightly more prominent, blunt ; fourth

tooth similar to third but smaller ; carapace width between fourth teeth slightly more than, or

subequal to, distance between third teeth. Front c. 0.26 times carapace width; c. 0.57-0.58

times fronto-orbital width ; moderately projecting ; bilobed ; lateral angles bluntly prominent ;

pre-orbital teeth represented as blunt shoulder. Posterior margin c. 0.37-0.4 times carapace

width. Carapace surface smooth and shining, finely punctate, finely wrinkled and roughened

anteriorly ; without setae. Upper orbital border concave, smooth, granular laterally. Lower

orbital border granular laterally ; inner angle formed by a rounded lobe. Antennal flagellum

small and entering orbit, not reaching beyond orbit. Basal antennal segment just touching

front. Basal antennular segment moderately broad, palp folds almost transversely. Inter-

antennular septum narrow.

Third maxilliped : merus distinctly shorter than ischium, wider than long, length c. 0.7-0.8

times breadth ; c. 0.4 times length of ischium. Ischium rectangular, length c. 1.6 times breadth ;

inner margin smooth.

Chelipeds markedly unequal on male holotype, but subequal on female paratype (pro¬

bably regenerating) ; large and robust ; merus with posterior border granulate ; lower border

Fig. 11. — A-H, Meriola rufomaculata gen. nov., sp. nov. Paratype $, MNHN-B22222, Fangataufa, Tuamotu/Gambier

Archipelago. A, frontal view ; B, third maxilliped ; C, abdomen ; D, sternum and abdomen ; E, F, G, first gonopod ;

H, second gonopod. I, Liomera ( Bruciana ) pediger (Alcock, 1898) : frontal view.

— 542 —

granulate ; anterior border minutely granulate ; carpus with two bluntly rounded teeth at inner

angle ; outer margin and upper surface smooth, finely punctate. Outer surface of palm

appearing smooth, but microscopically granular and punctate ; without setae. Inner surface of

palm microscopically granular. Immovable finger moderately long, with ventral ridge extending

a short distance on palm ; length of cutting edge c. 0.32-0.36 times length of propodus. Ventral

border of chela concave at base of fixed finger. Dorsal surface of dactyl smooth, rounded.

Fingers spooned ; a narrow gape between cutting margins on male.

Walking legs relatively long ; compressed ; slender ; all four pairs of similar length, c. 1.2

times maximum carapace width. Merus of third leg c. 4.2 times as long as wide. Carpus c. 2.4

times as long as wide. Propodus c. 2.5-2.6 times as long as wide. Dactyli c. 1.3 times length of

propodus. Dactyli straight and flattened ; terminating in an acute chitinous tip. Merus anterior

margin unarmed terminally. Carpus without accessory carinae on upper surface, but sometimes

with slight distal depression. All segments smooth ; without setae.

Male abdomen : five free segments ; third to fifth fused ; first and third segments subequal

in width. Segments three-five tapering. Segment six c. 1.5 times wider than long. Telson c. 0.9

times longer than wide ; evenly rounded, slightly longer than segment 6.

Gonopods : G1 long ; moderately stout ; curved ; tip shaped like “ swans head ”. Long

setae present on dorsal margin and continuing along lower edge of hollowed tip. G2 short ;

evenly curved ; tip short.

Sternum relatively broad, smooth, noticeably punctate.

Colouration. — Male specimen strongly marked with large, symmetrical orange/red

patches on the dorsal surface of carapace on the following regions : on 1F-1M ; on outer half

of 2M ; anterolaterally on 1L-3L ; small patch on 4L ; on 5L ; on 3M ; round patch on cardiac ;

and a round patch posterolaterally above bases of last walking legs. Legs with sub-proximal

and sub-distal bands on meri, and a single band more-or-less medially on other segments. Base

colour of carapace (after preservation) is a light blue-gray ; legs creamy yellow. Fingers dark,

as usual, with the colour of fixed finger extending obliquely backwards a short distance onto

the palm.

Incertae sedis

EURYOZIUS Miers, 1886

Pseudozius ( Euryozius ) Miers, 1886 : 141-142.

Euryozius ; Guinot, 19686 : 325-330.

Gardineria Rathbun, 1911 : 236. Guinot, 19686 : 325-330.

Type species. — Pseudozius bouvieri A Milne Edwards, 1869.

Diagnosis. — Carapace transversely oval ; anterolateral margin directed obliquely downward to the

angle of the buccal cavity and furnished with a stridulating mechanism. Orbit sub-entire, pear-shaped.

Antennules large, nearly transverse. Peduncular segments of antennae narrow ; basal segment falling far

— 543 -

short of front, following segment just touching front ; flagellum standing in orbital hiatus. Efferent ridge

well developed posteriorly but not reaching anterior edge of buccal cavity. Merus of maxillipeds expanded

at outer angle. Chelipeds stout, smooth. Legs slender, flattened (after Rathbun, 1911).

Remarks. — Guinot (1968Z>) discussed the relationships of Gardineria and Euryozius

Miers, 1886, at some length. At that time she elected to maintain them as separate genera

because, even though they are clearly closely allied, G. canora is only known from a single

female and she felt the structure of the male pleopods may be important in determining their

true status. Crosnier (in Serene, 1984) put Gardineria into the synonymy of Euryozius by

placing G. canora into Euryozius. After examining specimens of Euryozius bouvieri at the

MNHN I concur with Crosnier’s action.

Euryozius is now considered to have three species : E. bouvieri (A. Milne Edwards, 1868)

from the Western Atlantic; E. canorus (Rathbun, 1911) from the Seychelles, in the Indian

Ocean ; and E. danielae sp. nov. from French Polynesia, in the Pacific Ocean. The latter two

are known only from single females.

Euryozius danielae sp. nov.

(Fig. 12; pi. 13)

Etymology. — This elegant crab is named in honour of Dr Danièle Guinot of the MNHN Paris,

for her work on resolving the problems of this group.

Material examined. — French Polynesia. SMCB (J. Poupin) : Society Islands : Maupiti, Stn 272,

16°25.6'S, 152°17.5'W, trapped, 110 m, 24.06.1990 : 1 $ 26.7 x 16.3 mm (holotype, MNHN-B22217)

Description

Carapace transversely ovoid ; c. 1.65 times broader than long. Fronto-orbital width c. 0.9

times carapace length. Carapace convex anteriorly, flat from side to side. Regions poorly

defined ; cardiac indistinct ; intestinal indistinct, defined laterally by branchio-intestinal

grooves. Anterolateral margins regularly convex ; cristate, slightly raised, appearing granular

from above ; ending posteriorly in 2 projecting, spinous teeth, first forming widest point of

carapace, second with short oblique inwardly directed ridge. Anterolateral margins not

connected with outer edge of orbit ; ventral edge of margins finely striated, forming a long

stridulatory ridge, anteriorly curving beneath orbit but stopping clearly short of anterolateral

corner of buccal frame. Front c. 0.25 times carapace width ; c. 0.45 times fronto-orbital width ;

moderately deflexed ; bilobed with deep median incision ; lateral angles rounded, projecting ;

lateral margins diverging posteriorly. Posterior margin c. 0.25 times carapace width. Carapace

surface smooth, shining, punctate, surface coarsened with fine punctations in band across front

and behind anterolateral margins ; without setae. Upper orbital border irregularly granular

laterally ; concave ; inner angle rounded. Lower orbital border irregularly granular, outer edge

of orbit marked by a single prominent tubercle ; a second, similar, below middle of cornea, then

3-4 tubercles along inner part. Antennal flagellum small, entering orbit, reaching just short of

end of cornea. Orbital hiatus open. Basal antennal segment short, not touching front ;

— 544 —

Fig. 12. — Euryozius danielae sp. nov. Holotype 9, MNHN-B22217, Maupiti, Society Islands. A, frontal view ; B, third

maxilliped.

unarmed ; subrectangular. Basal antennular segment triangular, with anterior and lateral edges

raised to form a rim ; palp folding obliquely. Inter-antennular septum narrow.

Third maxilliped : merus distinctly smaller than ischium ; c. 0.6 times wider than long ;

antero-external angle produced, rounded ; c. 0.5 times length of ischium. Ischium sub-

triangular, c. 1.6 times longer than wide; inner margin smooth, upper surface punctate.

Maxillipeds without fringing setae. Palp articulating at inner distal margin of merus.

Chelipeds large and robust ; markedly unequal, left the larger on present specimen (ratios

for major cheliped) ; height of palm c. 0.5 times length, palm relatively elongated with dactyl

c. 1.2 times length of superior margin. Merus with posterior border smooth, bearing small

subdistal lobe, produced medially as strong rounded triangular lobe ; lower border smooth,

evenly rounded without a border marked ; anterior border smooth, with small, blunt,

ischio-meral tooth basally. Carpus with broad tooth at inner angle, inner margin produced as

a long, microscopically granular crest that rubs against the stridulatory crest on the carapace ;

outer margin smooth. Outer surface of palm smooth and punctate especially dorsally. Outer

surface of palm naked. Inner surface of palm smooth. Immovable finger moderately long ;

rounded on outer surface ; with low ventral ridge and with a series of spaced punctations in

furrow, extending posteriorly to level of insertion of dactyl. Length cutting edge c. 0.4 times

length propodus. Ventral border of chela straight. Dorsal surface of dactyl smooth, rounded.

Fingers pointed, crossing ; without a noticeable gape between the cutting margins

Walking legs relatively long; flattened; slender; third pair the longest, c. 1.25 times

maximum carapace width. Merus of third leg c. 4.5 times as long as wide. Carpus c. 2.7 times

as long as wide. Propodus c. 4.1 times as long as wide. Dactyli longer than propodi ; slender,

straight, and flattened ; terminating in an acute chitinous recurved tip. Anterior margin of

merus with a sub-distal shoulder ; anterior margin unarmed terminally. Carpus without

accessory carinae on upper surface. All segments smooth ; naked except for a few fine setae on

margins, particularly on inner edge of dactyli.

— 545 —

Sternum and abdomen : Sternum relatively broad. Female abdomen relatively narrow, not

covering sternum ; telson large and triangular, much longer than other segments.

Remarks. — Euryozius danielae sp. nov. is separable from E. canorus (Rathbun) in the

following respects : 1, the width to length ratio is markedly different (1.65 in danielae, 1.45 in

canorus) ; 2, the two lateral teeth are much more prominent and projecting in danielae ; 3, the

fingers of the chelipeds are almost entirely coloured black in danielae, but coloured like the

palm and only darkening distally in canorus ; 4, the frontal margin is not as strongly deflexed

as it is in canorus, and can be seen from above ; in particular the median incision is marked

and easily observed in danielae. Both the above species are easily separable from E. bouvieri (A.

Milne Edwards, 1869) by having the meri of the walking legs noticeably longer and more

slender.

Distribution. — Known only from the type locality in Society Islands in French

Polynesia, from a depth of 110 m.

Acknowledgments

I am most grateful to Dr Alain Crosnier of ORSTOM for asking me to undertake this study, and

for his support and encouragement ; and of course to J. Poupin of SMCB for his marvellous collections.

A large part of the work was undertaken while at the Laboratoire de Zoologie (Arthropodes), Muséum

national d’Histoire naturelle, Paris, under a grant from the Institut français de Recherche Scientifique

pour le Développement en Coopération (ORSTOM). The French Service Mixte de Contrôle Biologique

(SMCB) is also especially thanked for providing funds which enabled many of the illustrations to be made.

Dr Danièle Guinot kindly arranged the loan of comparative specimens. John Short and Jacques Rebière

are thanked for their photographic skills, and assistance with preparation of the plates. Ms Clare Bremner

and M. Maurice Gaillard executed the excellent illustrations. I thank too my wife Kathleen for her

support, practical assistance and love.

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Plate 1. — Banareia fatuhiva sp. nov. Holotype <J, MNHN-B22228, Tahuata, Marquises Islands. A, dorsal view ; B,

ventral view ; C, frontal view, showing chelipeds. Specimen partially denuded. Scale in mm.

— 550 —

Plate 2. — Demania garthi Guinot and Richer de Forges, 1981. , : J, MNHN-Unreg., Mururoa, Tuamotu Archipelago,

30.11.1989. A, dorsal view; B, ventral view; C, frontal view, showing chelipeds. Scale in mm.

— 551 —

Plate 3. — Demania mortenseni (Odhner, 1925). <J, MNHN-B22248, Akiaki, Tuamotu Archipelago. A, dorsal view ;

B, ventral view ; C, frontal view, showing chelipeds. Scale in mm.

— 552 —

Plate 4. — Paraxanthodes polynesiensis sp. nov. Holotype S, MNHN-B22225, Mururoa, Tuamotu Archipelago. A,

dorsal view ; B, ventral view ; C, frontal view, showing chelipeds. Scale in mm.

Plate 5. — Alainodaeus akiaki gen. nov., sp. nov. Holotype <J, MNHN-B22243, Rurutu, Austral Islands. A, dorsal

view ; B, ventral view ; C, frontal view, showing chelipeds. Scale in mm.

Plate 6. — Alainodaeus rimatara gen. nov., sp. nov. Holotype <J, MNHN-B22244, Akiaki, Tuamotu Archipelago. A,

dorsal view ; B, ventral view ; C, frontal view, showing chelipeds. Scale in mm.

Plate 7. — Epistocavea mururoa gen. nov., sp. nov. Paratype $, MNHN-B22234, Mururoa, Tuamotu Archipelago. A,

dorsal view ; B, ventral view ; C, frontal view, showing chelipeds. Scale in mm.

Plate 8. — Medaeus grandis sp. nov. Holotype <$, MNHN-B22218, Mururoa, Tuamotu Archipelago. A dorsal

B, ventral view ; C, frontal view, showing chelipeds. Scale in mm.

view ;

— 557 —

Plate 9. — Meractaea tafai gen. nov., sp. nov. Holotype S, MNHN-B22216, Acteons Maria, Tuamotu Archipelago.

A, dorsal view ; B, ventral view. A, dorsal view ; B, ventral view. Scale in mm.

Plate 10. — Rata tuamotense gen. nov., sp. nov. Holotype <J, MNHN-B22231, Fangataufa, Tuamotu/Gambier

Archipelago. A, dorsal view ; B, ventral view ; C, frontal view, showing chelipeds. Scale in mm.

— 559 —

Plate 11. — Lophozozymus bertonciniae Guinot and Richer de Forges, 1981. I, QM W8030, Hiva-Oa, Marquises

Archipelago. A, dorsal view ; B, ventral view ; C, frontal view, showing chelipeds. Scale in mm.

— 560 —

Plate 12. — Meriola rufomaculata gen. nov., sp. nov. Paratype $, MNHN-B22222, Fangataufa, Tuamotu/Gambier

Archipelago. A, dorsal view ; B, frontal view. Scale in mm.

— 561 —

Plate 13. — Euryozius danielae sp. nov. Holotype $, MNHN-B22217, Maupiti, Society Islands. A, dorsal view; B,

frontal view. Scale in mm.

Achevé d'imprimer le 26 février 1993.

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