A Stereo-Atlas of Ostracod Shells

edited by I. Boomer, D. J. Horne, A. R. Lord, D. J. Siveter,

and J. E. Whittaker

Volume 22, Part 1; 31st August, 1995

Published under the aegis of the British Micropalaeontological Society, London

ISSN 0952-7451

Editors

Dr Ian Boomer, School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ. Tel: +1603 592841;

Fax: +1603 507719; Email: i.boomer@uae.ac.uk.

Dr David J. Home, School of Earth Sciences, University of Greenwich, Chatham Maritime, Kent ME4 4AW. Tel:

+181 331 9841; Fax: +181 331 9805; Email: d.j.home@greenwich.ac.uk.

Professor Alan R. Lord, Department of Geological Sciences, University College London, Gower Street, London

WC1E 6BT. Tel: +171 380 7131; Fax: +171 388 7614; Email: dean.maps@ucl.ac.uk.

Dr David J. Siveter, Department of Geology, The University, Leicester LEI 7RH. Tel: +1 16 523925; Fax: +1 16

523918; Email: djs@leicester.ac.uk.

Dr John E. Whittaker, Department of Palaeontology, The Natural History Museum, Cromwell Road, London SW7

5BD. Tel: +171 938 8837; Fax: +171 938 9277; Email: jepw@nhm.ac.uk

Editorial Board

Dr J.-P. Colin, Esso Production Research - European, 213 Cours Victor Hugo, F-33321 Begles, France.

Dr M.A. Ayress, Department of Geology, The Australian National University, G.P.O. Box 4, Canberra, ACT 2601,

Australia.

Professor R.F. Lundin, Department of Geology, Arizona State University, Tempe, Arizona 85287-1404, U S A.

DrRE.L. Schallreuter, Geologisches-Palaontologisches Institut, Universitat Hamburg, Bundesstrasse 55, D-20146

Hamburg, Germany.

Professor N. Ikeya, Institute of Geosciences, Shizuoka University, Shizuoka 422, Japan.

Officers of the British Micropalaeontological Society

Chairman: Professor A.R. Lord, Department of Geological sciences. University College London, Gower Street,

London WC1E6BT.

Secretary: Mrs S.L. Matthews, c/o Department of Geological Sciences, University College London, Gower Street,

London WC1E6BT.

Treasurer: Dr J.B. Riding, British Geological Survey, Keyworth, Nottingham NG12 5GG.

Membership Treasurer: Dr L.T. Gallagher, Network Stratigraphic Consulting Ltd., Unit 57, The Enterprise Centre,

Cranbome Road, Potters Bar, Hertfordshire EN6 3DQ.

Editor, Journal of Micropalaeontology : Professor J.W. Murray, Department of Geology, Southampton

Oceanography Centre, Empress Dock, Southampton SOM 3ZH.

Editor, Newsletter of Micropalaeontology: Dr A.J. Powell, Millenia Ltd., Unit 3, Weyside Park, Newman Lane,

Alton, Hampshire GU34 2PJ.

Calcareous Nannofossil Group: Chairman - Dr J.A. Burnett; Secretary - Ms D.E. Windley.

Conodont Group: Chairman - Dr S.J. Tull; Secretary - Dr I.J. Sansom.

Foraminifera Group: Chairman - Dr M.A. Kaminski; Secretary - Mr M.D. Bidgood.

Ostracod Group: Chairman - Dr D.J. Home; Secretary - Dr M. Williams.

Palynology Group: Chairman - Professor D.J. Batten; Secretary - Mr D. McLean.

Instructions to Authors

Contributions illustrated by scanning electron micrographs of Ostracoda in stereo-pairs are invited. All contributions

submitted for possible publication in A Stereo-Atlas of Ostracod Shells are peer-reviewed by an appropriate

international specialist. "Instructions to Authors" and plate blanks for mounting photographs may be obtained from

any Editor. Manuscripts should be submitted to Dr Ian Boomer.

The front cover shows (upper) the holotype (RV, dorsal view, BMNH no. OS 14654) and (lower) a paratype (LV,

external lateral view, BMNH no. OS 14653) of Pariceratina ubiquita Boomer, 1994 from the Palaeogene of ODP

Site 865, Central Pacific Ocean. This species was described in A Stereo-Atlas of Ostracod Shells, 21, 79-86.

Stereo-Atlas of Ostracod Shells 22 (1) 1-4 (1995) Baltocyamus primarius (1 of 4)

595.336.16 (113.313) (474.2 : 161 .026.59) 551.351 + 552.52

ON BALTOCYAMUS PRIMARIUS MEIDLA gen. et sp. nov.

by Tonu Meidla

(Institute of Geology, Estonian Academy of Sciences & Institute of Geology, Tartu University, Estonia)

Genus BALTOCYAMUS gen. nov.

Type-species: Baltocyamus primarius sp. nov.

Balto (the genus originates from the Baltic area) and cyamus, hinting at its bean-like shape (and as used in several

primitiopsid names). Gender, masculine.

Small, strongly convex Anisocyaminae with velum proceeding along entire free margin; male velum bend-like,

female differing by posterior concave open dolon. Left valve operlaps right valve along the contact margin.

This genus differs from Clavofabella Martinsson, 1955 and Anisocyamus Martinsson, 1960 by having the velum

separated from the lateral surface by a furrow. In addition, it differs from Primitiopsis Jones, 1887 in possessing

an open dolon in females. Baltocyamus is assigned to the Anisocyaminae Martinsson, 1960 based on the lack of

distinct S2 and L2.

Baltocyamus resembles the non-dimorphic genus Pyxion Thorslund, 1948 in having a flat, wide velum which

is similar to the marginal lobe (velum?) of the latter. The contact conditions are the same as Pyxion

posterobicarinatum Schallreuter (Stereo-Atlas Ostracod Shells, 6, 87-90, 1979): the left valve bears an outer list

and inner semi-groove, thus complimenting the marginal structures of the right valve. This condition is the

reverse of that in Anisocyamus elegans (Harris, 1957) (see Siveter & Williams, Stereo-Atlas Ostracod Shells, 15,

107-114, 1988) or A. bassleri (Harris, 1931) (see Siveter & Williams, Stereo-Atlas Ostracod Shells, 15, 1 15-122,

Explanation of Plate 22, 2

Fig. 1, 9 car., post (Os 3292, 0.77 mm long and 0.36 mm wide). Fig. 2, 9 car., It. lat (Os 3291, 0.73 mm long). Fig. 3, o* car., rt. lat.

(holotype, Os 3178, 0.78 mm long). Fig. 4, 9 car., rt. lat. (Os 3293, 0.77 mm long). Fig. 5, 9 car. It. lat. (Os 3179, 0.77 mm long).

Fig. 6, juv. car. It. lat. (Os 3283, 0.69 mm long). Fig. 7, o* car., post. (Os 3285, 0.76 mm long and 0.35 mm wide).

Scale A (250,um; x57), figs. 1-7.

Stereo-Atlas of Ostracod Shells 22, 3 Baltocyamus primarius (3 of 4)

1988). In some representatives of the genus Pyxion the adductorial sulcus may also be poorly developed (e.g. P.

posterobicarinatum) .

The presence of a distinct velum in both heteromorphs and tecnomorphs of an Anisocyaminae species necessi-

tates modification of the diagnosis for the subfamily.

Baltocyamus primarius sp. nov.

Latin, primarius notable, remarkable, one of the first; alluding to its characteristic, striking ornamentation and

to the fact that it is one of the oldest known Anisocyaminae in Baltoscandia.

Institute of Geology, Estonian Academy of Sciences, no. Os 3178; tecnomorphic carapace.

[Paratypes: Institute of Geology, Estonian Academy of Sciences, nos. Os 3179-Os 3298],

Tdrremagi, Rakvere, West Viru District, Estonia, approximately lat. 59° 21 ' 31 " N, long. 26° 21 ' 15" E; Hirmuse

Formation, Oandu Stage, Viruan, Ordovician.

Carapace small (length up to 0.79 mm), high, strongly convex, slightly postplete with considerably larger

anterior cardinal corner. Dorsum epicline. Bend-like velum of male extends along the entire free margin, widen-

ing ventrally where it merges with the lateral surface. Female has posterior concave open dolon. Lateral surface

irregularly, coarsely-pitted. Left valve overlaps right valve along the contact margin.

Institute of Geology, Estonian Academy of Sciences, nos. Os 3178 (holotype, o* car.: PI. 22, 2, fig. 3), Os 3179

(9 car.: PI. 22, 2, fig. 5), Os 3281 (9 car.: PI. 22, 4, fie. 4), Os 3283 (juv. car.: PI. 22, 2, fig. 6), Os 3285 (O' car.:

PI. 22, 2, fig. 7), Os 3286 (O' car.: PI. 22, 4, fig. 3), Os 3288 (9 car.: PI. 22, 4, fig. 7), Os 3289 (9 car.: PI. 22,

4, fig. 5), Os 3291 (9 car.: PI. 22, 2, fig. 2), Os 3292 (9 car.: PL 22, 2, fig. 1), Os 3293 (9 car:. PI. 22, 2, fig.

4), Os 3295 (o- LV: PI. 22, 4, fig. 8), Os 3296 (9 RV: PI. 22, 4, fig. 1), Os 3297 (9 RV: PI. 22, 4, fig. 2) and

Os 3298 (9 LV: PI. 22, 4, fig. 6).

All of the figured specimens are from a single sample from the type locality.

B. primarius is known from about 120 specimens.

Known only from the Hirmuse Formation, Oandu Stage, Caradoc Series, Ordovician, at a few localities in the

vicinity of Rakvere, Estonia: the Vinni core (depth 43.25 m) and Tdrremagi section.

Explanation of Plate 21, 4

Fig. 1 , 9 RV, int. lat. (Os 3296, 0.72 mm long). Fig. 2, 9 RV, int. lat. (Os 3297, 0.70 mm long). Fig. 3, O' car., vent. (Os 3286, 0.77 mm

long). Fig. 4, o' car., It. lat. (Os 3281, 0.79 mm long). Fig. 5, 9 car., vent. (Os 3289, 0.73 mm long. Fig. 6, 9 LV, int. lat. (Os 3298,

0.78 mm long). Fig. 7, 9 car., vent., half-opened (Os 3288, 0.76 mm long). Fig. 8, o’ LV, int. lat. (Os 3295, 0.75 mm long).

Scale A (250 ^tm; x57), figs. 1-8.

Derivative of name:

Holotype:

Type locality:

Diagnosis:

Figured specimens:

Remarks:

Distribution:

Derivation of name:

Diagnosis:

Remarks:

Stereo-Atlas of Ostracod Shells 22, 2 Baltocyamus primarius (2 of 4)

I

I

I

I

I

I

Stereo-Atlas of Ostracod Shells 22 (2) 5-8 (1995) Dizygopleura landesi (1 of 4)

595.336.21 (1 13.333) (768: 162.089.35 + 766 : 162.097.34): 551.351 + 552.54

ON DIZYGOPLEURA LANDESI ROTH

by Robert F. Lundin

(Arizona State University, Tempe, U.S.A.)

Dizygopleura landesi Roth, 1929

1929 Dizygopleura landesi sp. nov., R. Roth, J. Paleont., 3, 341, pi. 35, figs. 7a-i.

1965 Dizygopleura landesi Roth; R. F. Lundin, Bull. Okla. geol. Surv., 108, 45.

Lectotype: United States Museum of Natural History (USNM), Washington D.C., U.S.A.; no.

USNM 80645 C; adult carapace (see Lundin, 1965).

Type locality: The precise locality of the type specimens cannot be established, but it is most likely in the

Lawrence Uplift area of Pontotoc County, Oklahoma; approximately lat. 34°25'N, long.

96°50'W (see Roth 1929, Lundin 1965, T. W. Amsden, Bull. Okla. geol. Surv., 84, panel 2, 1960).

This locality is probably of late Ludlow or Pridoli Series, Silurian, in age.

Figured specimens: Department of Geology, Arizona State University, (ASU), nos. X-214 (o* car.: PI. 22, 6, figs. 1-3),

X-215 (9 RV: PI. 22, 6, fig. 4), X-216 (9 LV: PI. 22, 6, fig. 5), X-217 (o* LV: PI. 22, 8, fig. 1),

X-218 (9 car.: PI. 22, 8, figs. 2-4), X-219 (o* LV: PI. 22, 8, fig. 5). All figured specimens are adults.

ASU X-214, ASU X-216, ASU X-217 and ASU X-219 are from approximately 49 m above the

base of the Henryhouse Formation in the Lawrence Uplift, Pontotoc County, Oklahoma (Section

P3, sample 11 of Lundin 1965). ASU X-215 is from approximately 12 m below the top of the

Explanation of Plate 22, 6

Figs. 1-3, o r car. (ASU X-214, 1259 pm long): fig. 1, ext. vent.; fig. 2, ext. dors.; fig. 3, ext. rt. lat. Figs. 4, 9 RV (ASU X-215, 1315 pm

long): int. lat. Fig. 5, 9 LV (ASU X-216, 1184/rm long): int. lat.

Scale A (200 /rm; x41), figs. 1-3; scale B (200 pm; x40), fig. 4; scale C (200 pm; x43), fig. 5.

Stereo-Atlas of Ostracod Shells 22, 7

Dizygopleura landesi (3 of 4)

Diagnosis:

Remarks:

Distribution:

A ckno wledgement:

Brownsport Formation in the Pope Quadrangle, Perry County, Tennessee; ASU X-218 is from the

middle of the same formation in the Olive Hill Quadrangle, Hardin County, Tennessee. All of these

specimens are from the late Ludlow of Pridoli Series, Silurian.

Dizygopleura species with distinct, crescent-shaped LI, weakly bulbous L2 connected ventrally with

L3 around slightly angulate S2. L3 and L4 confluent dorsally. L4 carina-like in male, swollen in

female. Ventral connection of LI and L4 more distinct in males than females, carina-like in some

male specimens. L2, L3 and the ventral connection of LI and L4 fused below S2. Distinct peri-

marginal carinae on both valves. Left/right overreach strong ventrally.

D. landesi is distinguished from D. chaleurensis Copeland, 1962 {Bull. geol. Surv. Can., 91, 40) by

its larger size, its distinct ventral left/right overreach and by the fusion of L2 and L3 with the

connecting lobe.

Lundin (1965, 45) described the ontogeny of this species based on a population from the Henry-

house Formation of Oklahoma. This study, in combination with Adamczak’s ( Acta palaeont. pol.,

6, Text-Pi. 1, 1961) definitive analysis of the ontogeny of Poloniella Gtirich, makes it clear that

these two genera are closely related.

With this report of D. landesi from the Brownsport Formation, the geographic occurrence of the

species is extended from south-central Oklahoma to western Tennessee. The species is known to

range from near the base to near the top of the Henryhouse Formation in the Lawrence uplift area

of Oklahoma and from 0.6 to 24 m above the base of the Brownsport Formation of western

Tennessee. These strata range from middle Ludlow to late Pridoli in age.

Support from NATO (Grant 870445) is gratefully acknowledged.

Explanation of Plate 22, 8

Fig. 1, cr LV (ASU X-217, 1165 pm long): int. lat. Figs. 2-4, 9 car. (ASU X-218, 1240 pm long): fig. 2, ext. dors.; fig. 3, ext. rt. lat.;

fig. 4, ext. vent. Fig. 5, cr LV (ASU X-219, 1240 ^urn long); int. lat.

Scale A (200 //m; x44), fig. 1; scale B (200 /rm; x41), figs. 2-5.

Dizygopleura landesi (4 of 4)

Dizygopleura landesi (2 of 4)

Stereo-Atlas of Ostracod Shells 22, 6

Stereo-Atlas of Ostracod Shells 22, 8

Stereo-Atlas of Ostracod Shells 22 (3) 9-12 (1995) Longiscella grandis (1 of 4)

595.337.23 (113.331) (420 : 162.003.52) : 551 .351 + 552.52

ON LONGISCELLA GRANDIS (JONES & HOLL)

by Lee E. Petersen & Robert F. Lundin

(Anadarko Petroleum Corporation, Houston & Arizona State University,

Tempe, U.S.A.)

Longiscella grandis (Jones & Holl, 1869)

1869 Cytherellina siliqua (Jones) var. grandis Jones & Hall var. nov., T. R. Jones & H. B. Holl, Ann. Mag. nat. Hist., (4), 3, 217, pi. 14, figs. la-c.

1869 Cytherellina siliqua (Jones) var. ovata Jones & Holl var. nov., T. R. Jones & H. B. Holl, Ann. Mag. nat. Hist., (4), 3, 217, pi. 14, fig. 4.

1869 Cytherellina siliqua (Jones) var. tersa Jones & Holl var. nov., T. R. Jones & H. B. Holl, Ann. Mag. nat. Hist., (4), 3, 217, pi. 14, figs. 3a-c.

1887 Bythocypris grandis (Jones & Holl); T. R. Jones, Ann. Mag. nat. Hist., (5), 19, 185.

1887 Cytherellina siliqua var. ovata Jones & Holl; T. R. Jones, Ann. Mag. nat. Hist., (5), 19, 185.

1887 Cytherellina ( Bythocypris ?) tersa Jones & Holl; T. R. Jones, Ann. Mag. nat. Hist., (5), 19, 191.

1991 Longiscella grandis (Jones & Holl); R. F. Lundin, L. E. Petersen & D. J. Siveter, J. Micropalaeontol., 9, pi. 1, fig. 10.

Lectotype: Designated herein. The Natural History Museum (BMNH), London, England, no. 1 2068; adult carapace. Jones and Holl (1869)

indicated that several specimens were available to them. The lectotype agrees well with the single specimen which they illustrated.

Type locality: Railway tunnel near The Wych, Malvern, England; approximately lat. 52°05'N, long. 2°21'W. National Grid Ref.: SO760428.

Woolhope Limestone Formation, Sheinwoodian, Wenlock Series, Silurian.

Figured specimens: Department of Geology, Arizona State University, (ASU), nos. X-133 (adult car.: PI. 22, 10, figs. 1-3), X-258 (adult car.: PI. 22,

10, fig. 4; PI. 22, 12, fig. 5), X-259 (juv. car.: PI. 22, 10, fig. 5), X-260 (juv. car.: PI. 22, 12, fig. 6.), X-261 (transverse section

of adult car.: Text-fig. la), X-262 (longitudinal section of adult car.: Text-fig. lb). BMNH I 2068 (lectotype, adult car.: PI. 22,

12, figs. 1-4).

ASU X-133, ASU X-258, ASU X-261 and ASU X-262 are from the lower part of the Apedale Member, Coalbrookdale

Formation at Buildwas Bridge, Shropshire, England (locality 34 of Lundin et at., 1991). ASU X-259 and ASU X-260 are from

Explanation of Plate 22, 10

Figs. 1-3, adult car. (ASU X-133, 2056,0111 long): fig. 1, ext. It. lat.; fig. 2, ext. rt. lat.; fig. 3, ext. vent. Fig. 4, adult car. (ASU X-258,

1953 jtm long): ext. dors. Fig. 5, juvenile car. (ASU X-259, 959 pm long): ext. rt. lat.

Scale A (300 jrm; x25), figs. 1-3; scale B (300 j/m; x27), fig. 4; scale C (200 /tm; x54), fig. 5.

Stereo-Atlas of Ostracod Shells 22, 1 1

Longiscella grandis (3 of 4)

Diagnosis:

Remarks:

Distribution:

A cknowledgements:

the upper part of the Buildwas Formation at Buildwas Abbey, Shropshire, England (locality 37 of Lundin et al., 1991). All of

these specimens are from approximately lat. 52°39'N, 2°33'W; the lower to middle Sheinwoodian, Wenlock Series, Silurian.

Longiscella species with subreniform lateral outline and subrectangular longitudinal outline. Ventriculus and straguloid processes

poorly developed. Adductorial recess distinct. Surface smooth.

Comparison of the type specimen of Cytherellina siliqua var. grandis Jones & Holl with the type specimen of Longiscella caudalis

(Jones, 1889), the type-species of the thlipsurid Longiscella Krandijevsky, indicates that the two species are congeneric. Valve rela-

tionships, contact margin features, shape and hingement in the two species are basically alike. We regard the varieties C. siliqua

var. tersa and C. siliqua var. ovata erected by Jones & Holl (1869, op cit.) as synonyms of L. grandis, the former being based on

a juvenile specimen and the latter being based on a minor shape variant. Bythocypris holli var. oblonga Jones (Ann. Mag. nat.

Hist., (6), 4, 270, 1889), from the upper Llandovery and lower Wenlock of Gotland, is a Longiscella species and differs from L.

grandis in its much smaller size and the greater convexity of the lateral surfaces of its valves.

All of the approximately 40 specimens from England are carapaces (many of which are deformed). Accordingly, the hingement

and contact margin structures are interpreted from longitudinal and transverse thin sections of carapaces (Text-fig. 1) and from

single valves of the close relative, L. oblonga (Jones, 1889).

L. grandis is known from late Llandovery (upper part of the Purple Shales Formation) to early Wenlock (Buildwas Formation

and lower part of the Coalbrookdale Formation), Silurian strata of Britain (Lundin et al., 1991).

We gratefully acknowledge support from NATO (Grant 870445) and the National Science Foundation (Grant EAR-8200816).

Text-fig. 1, Outline drawings from photographs of thin sections of L. grandis: la, transverse section (ASU X-261, anterior view, x35, 1109/rm high;

sample MS 544); lb, longitudinal section (ASU X-262, ventral view, x34, 2130 pm long; sample MS 541).

Explanation of Plate 22, 12

Fig. 1-4, adult car. (I 2068, 1900 /tm long): fig. 1, ext. rt. lat.; fig. 2, ext. It. lat.; fig. 3, ext. dors.; fig. 4, ext. vent. Fig. 5, adult car.

(ASU X-258, 1953^171 long): ext. rt. lat. Fig. 6, juvenile car. (ASU X-260, 1523 pm long); ext. rt. lat.

Scale A (300 j/m; x27), figs. 1-5; scale B (300 j/m; x34), fig. 6.

Stereo-Atlas of Ostracod Shells 22, 10

Longiscella grandis (2 of 4)

Stereo-Atlas of Ostracod Shells 22, 12

Longiscella grandis (4 of 4)

Stereo-Atlas of Ostraeod Shells 22 (4) 13-16 (1995) Microcheilinella gigas (1 of 4)

595.337.2 (113.333) (485 : 161 .018.56): 551.351 +552.54

ON MICROCHEILINELLA GIGAS BIRKMANN & LUNDIN sp. nov.

by Harry Birkmann & Robert F. Lundin

(Arizona State University, Tempe, U.S.A.)

Microcheilinella gigas sp. nov.

Holotype:

Type locality:

Derivation of name:

Figured specimens:

Diagnosis:

Department of Geology, Arizona State University (ASU), no. ASU X-263; adult carapace.

[Paratypes: Arizona State University, nos. ASU X-264-X-267],

Lower part of the cliff section approximately 100 m NNW of point 22, 23 on 5 I Hoburgen SO &

5 J Hemse SV topographic map sheet, Gotland, Sweden (locality Hoburgen Ha of Martinsson,

Bull. geol. Instn Univ. Uppsala , 41, 59, 1962). Approximately lat. 56°55'N, long. 18°8'E.

Latin, gigas, a giant; referring to the large size of the species.

Department of Geology, Arizona State University (ASU), nos. X-263 (holotype, adult car.: PI. 22,

14, figs. 1-4; PI. 22, 16, fig. 1), X-264 (paratype, adult car.: PI. 22, 16, fig. 2), X-265 (paratype,

juv. car.: PI. 22, 16, fig. 3), X-266 (paratype, adult car.: PI. 22, 16, fig. 4), X-267 (paratype,

juvenile RV: PI. 22, 16, fig. 5).

ASU X-267 is from the contact between the reef and the overlying bedded limestones, near the

top of the cliff at the type section. All of the other figured specimens are from the type locality.

All figured specimens are from the Hamra Beds, Ludfordian, Ludlow Series, Silurian.

Large Microcheilinella species with a distinct ventriculus; antero- and postero-lateral surfaces

slightly compressed producing a distinctive disk-shaped longitudinal outline. Maximum width at or

Explanation of Plate 22, 14

Figs. 1-4, adult car. (holotype, ASU X-263, 1598 am long): fig. 1, ext. rt. lat.; fig. 2, ext. dors.; fig. 3, ext. It. lat.; fig. 4, ext. vent.

Scale A (400 pm; x33), figs. 1-4.

Stereo-Atlas of Ostraeod Shells 22, 15 Microcheilinella gigas (3 of 4)

slightly posterior to midlength. Perimarginal carinae on the posteroventral and anteroventral part

of admarginal surface of right valve. Anterior admarginal surface of juvenile right valve crenulate.

Dimorphic(?) by posteriorward displacement of maximum width in heteromorph.

Remarks: This very distinctive Microcheilinella species is characterized by its very large size, the ventriculus,

and the perimarginal carinae on the right valve. It differs from all other Pachydomellidae by its dis-

tinctive longitudinal outline, which is present in juveniles as well as adults. All known adult speci-

mens are carapaces and, thus, crenulation of the anterior admarginal surface cannot be verified in

adults. The length : width ratio of this species is distinctly greater than in species of Daleiella

Boucek.

Distribution: Known from eight samples at the type locality, ranging from near the base to near the top of the

Hamra Beds, Ludfordian, Ludlow Series, Silurian, of Gotland, Sweden.

Text-fig. 1. Size dispersion of 21 carapaces from the type locality (Hoburgen Ila,

sample MS 2). Triangle = holotype; squares = figured paratypes.

1200

1000

2:

S 800

600

1000 1200 1400 1600 1800

Length, pm

Explanation of Plate 22, 16

Fig. 1, adult, car. (holotype, ASU X-263, 930 pm high): ext. ant. Fig. 2, adult car. (paratype, ASU X-264, 1541 pm long): ext. rt. lat.

Fig. 3, juv. car. (paratype, ASU X-265, 1100pm long): ext. rt. lat. Fig. 4, adult car. (paratype, ASU X-266, 1579pm long): ext. rt.

lat. Fig. 5, broken juv. RV (paratype, ASU X-267, 1203 pm long): int. of anterior part of valve.

Scale A (400pm; x30), figs. 1, 4; scale B (400pm; x33), figs. 2, 3; scale C (100pm; x 106), fig. 5.

Stereo-Atlas of Ostracod Shells 22 (5) 17-20 (1995) Ordovizona immanis (1 of 4)

595.336 (113.31) (261 .4 : 162.047.50): 551.351 + 552.54

ON ORDOVIZONA IMMANIS BECKER

by Gerhard Becker

( Senckenberg Museum, Frankfurt am Main, Germany)

Ordovizona immanis Becker, 1994

1994 Ordovizona immanis sp. nov., G. Becker, Scr. geol., 107, 8, pi. 1, figs. 1-4.

1994 Ordovizona immanis Becker; G. Becker in J. E. van Hinte & A. Ruffman, Scr. geol., 107, pi. 7, figs. 1-5.

Holotype:

Type locality:

Figured specimens:

Diagnosis:

Nationaal Natuurhistorisch Museum, Leiden, The Netherlands, no. RGM 414005; a silicified adult left

valve.

From seamount ‘Orphan Knoll’ (see Ruffman, A. & van Hinte, J. E., Geol. Surv. Pap. Can., 71-23,

407-449, 1973), in the Labrador Sea, approximately 500 km NE of Newfoundland. The material was

obtained from a single biologic dredge (LYNCH 7/11/71 cruise, station no. D3-7-1 1-71) on May 23, 1971 ,

at an average position of 50°33'N, 46°22'W and from an average depth of 1775 m (see Ruffman, A.,

Geol. Surv. Can. Open File, 2065, 1989). The specimens of Ordovizona immanis come from a single

pebble of middle to late Ordovician age.

Nationaal Natuurhistorisch Museum (RGM), Leiden, The Netherlands, nos. RGM 414005 (adult LV: PL

22, 18, figs. . 1 , 4; PI. 22, 20, fig. 1), RGM 414006 (adult LV: PI. 22, 20, fig. 3), RGM 414007 (juv. LV:

PI. 22, 20, fig. 2) and RGM 414008 (adult LV: PI. 22, 18, figs. 2, 3).

All figured specimens are from the type locality.

Species of Ordovizona with a short, straight, ventrally deepened sulcus (S2), a bow shaped dorsal carina,

and pronounced costae on the lateral surface which are reduced or absent towards the posterior margin.

Explanation of Plate 22, 18

Figs. 1, 4, adult LV (holotype, RGM 414005, 700 pm long): fig. 1, ext. lat.; fig. 4, int. lat. Figs. 2, 3, adult LV (RGM 414008, 655 am

long): fig. 2, vent.; fig. 3, ant.

Scale A (200 pm; X100), figs. 1, 3, 4; scale B (200 pm; x90), fig. 2.

Stereo-Atlas of Ostracod Shells 22, 19 Ordovizona immanis (3 of 4)

Remarks: The type-species of Ordovizona Schallreuter, 1969 ( Geologie , 18, 205), O. sulcata, is similar to O. immanis

in having a subamplete outline, a similar number of costae on the lateral surface (with reticulation devel-

oped between the costae) and a distinct dorsal carina and narrow velum. O. sulcata differs from O.

immanis by having a narrower and more clearly defined sulcus (S2) and by the lateral costae which are

developed even posteriorly. Ordovizona longa Schallreuter, 1983 {Neues Jb. Geol. Palaont. Mh., 1983, 10,

603) is more elongate than O. immanis, has a less distinct sulcus (S2), a less prominent dorsal carina and

more numerous but weaker costae on the lateral surface.

Ordovician forms with a monotiopleurid outline and short, mid-dorsally situated sulcal depressions

(e.g. Ordovizona) were believed by Schallreuter (Wiss. Z. Ernst Moritz Arndt-Univ. Greifswald, 17, 135,

1968) to be the oldest known members of the Superfamily Kirkbyacea Ulrich & Bassler, 1906. Becker

{Senckenberg. leth., 70, 150, 1990), however, considered them to be related to the Family Kirkbyellidae

Sohn, 1961 (Order unknown). Griindel (Z. geol. Wiss., 6, 74, 1978) suggested that such forms possibly

belong to the Family Monotiopleuridae Guber & Jaanusson, 1964 (Superfamilv unknown). The early

Palaeozoic monotiopleurids and kirkbyaceans sensu Schallreuter and the pE/iogenetically younger

kirkbyellids are probably related groups. The Kirkbyacea are a relatively youi p 6roup with, comparatively

advanced carapace architecture; the arcyzonid species ‘Amphissites’ primaevus Roth, 1929, from the late

Silurian of Oklahoma, U.S.A., is considered by some authors to be the first true kirkbyacean (Becker, G.

& Lundin, R. F., Stereo-Atlas Ostracod Shells, in press).

O. immanis occurs together with a rich ostracod fauna (see Becker, 1994, 4-9), including species refer-

able to middle to late Ordovician genera such as Anticostiella Copeland, 1973 {Geol. Surv. Pap. Can.,

72-43, 9) and Ectoprimitoides Berdan, 1988 {Mem. Bur. Mines Mineral Resourc., New Mex. , 44, 278).

Distribution: Known only from the type locality. The material recovered on Orphan Knoll is considered to be from

bedrock (Becker, 1994).

Explanation of Plate 22, 20

Fig. 1, adult LV, dors. obi. (holotype, RGM 414005, 700pm long). Fig. 2, juv. LV, dors. (RGM 414007, 580pm long). Fig. 3, adult

LV, ext. lat. (RGM 414006, 670 pm long).

Scale A (200pm; xlOO), figs. 1-3.

Stereo-Atlas of Ostracod Shells 22, 20 Ordovizona immanis (4 of 4)

Stereo-Atlas of Ostracod Shells 22 (6) 21-24 (1995) Inversibolbina lehnerti (1 of 4)

595.336 (82: 164.069.30); 551.351 + 552.55

ON INVERSIBOLBINA LEHNERTI SCHALLREUTER gen. et sp. nov.

by Roger E. L. Schallreuter

(University of Hamburg, Germany)

Genus INVERSIBOLBINA gen. nov.

Type-species: Inversibolbina lehnerti sp. nov.

Latin inversus ‘turned upside down’, plus the generic name Bolbina; alluding to the reversal of

valve overlap conditions. Gender, feminine.

Small to medium-size, elongate palaeocope. Unisulcate; short, vertical sulcus (S2) in dorsal half of

valve and just in front of mid length. Indistinct, flattish bulb occurs immediately anterior of sulcus.

No further special lobes but domicilium generally most inflated in ventrocentral region. Flange-like

admarginal ridge in anterior half of valve, narrowing in centroventral region to form a rounded

bend (larger valve) or even narrower ridge (smaller valve). Reversal of valve overlap conditions

occurs; larger left valve or right valve forms a broad, overlapping vertical flange between the free

margin and adventral bend. Surface smooth.

The systematic position of the new genus is uncertain. The main adventral sculpture does not seem

to be a velum, but rather a differentiated marginal sculpture similar to that in Eographiodactylus

sulcatus (see Schallreuter, R. E. L., Stereo-Atlas Ostracod Shells 7, 1-8, 1980). The latter differs

from Inversibolbina by the different construction of its marginal flange, which terminates

posteriorly in a long spine.

Derivation of name:

Diagnosis:

Remarks:

Explanation of Plate 22, 22

Figs. 1, 2, car. (holotype, GPIMH 3607, 835/un long); fig. 1, ext. rt. lat . : fig. 2, ext. vent, oblique. Fig. 3, car. It. lat. (GPIMH3608,

884 /jm long).

Scale A (250 //m; x78), figs. 1, 2; scale B (250 /um; x72), fig. 3.

Stereo-Atlas of Ostracod Shells 22, 23 Inversibolbina lehnerti (3 of 4)

Inversibolbina lehnerti sp. nov.

Holotype:

Type locality:

Derivation of name:

Diagnosis:

Figured specimens:

Distribution:

Geologisch-Palaontologisches Institut und Museum, University of Hamburg, Germany (GPIMH),

no. 3607; a carapace.

[Paratype: GPIMH 3609],

Quebrada de Las Aguaditas, San Jose de Jachal (Hoja 18c), San Juan, Argentina; approximately

latitude 30°18'S, longitude 68°48'W. Las Aguaditas Formation, Llanvirn-Caradoc series,

Ordovician.

After Dr Oliver Lehnert, who provided the samples.

As for the genus, which is currently monotypic.

Geologisch-Palaontologisches Institut und Museum, University of Hamburg (GPIMH) nos. 3607

(car.: PI. 22, 22, figs. 1, 2), 3608 (car.: PI. 22, 22, fig. 3; PI. 22, 24, fig. 3), and 3609 (car.: PI. 22,

24, figs. 1, 2).

All figured specimens are from the type locality and type section of the Las Aguaditas

Formation. The specimens are from material collected by Dr Oliver Lehnert: samples SE-CON 51

(specimen 3608) and SE-CON 46 (all other specimens); Pygodes anserinus conodont zone.

Known only from type locality, Ordovician of Argentina.

Explanation of Plate 22, 24

Figs. 1, 2, car. (paratype, GPIMH 3609, 1012,t/m long): fig. 1. ext. vent, oblique; fig. 2, ext. It. lat. Fig. 3, car. ext. vent, oblique

(GPIMH 3608).

Scale A (250/rm; x65), figs. 1, 2; scale B (250 x75), fig. 3.

Stereo-Atlas of Ostracod Shells 22 (7) 25-28 (1995) Artesiocythere artesica (1 of 4)

595.337.14 (116.313 + 116.331) (943 : 163. 142.29) 551.35 + 552.52

ON ARTESIOCYTHERE ARTESICA KROMMELBEIN

by Caroline A. Maybury & Robin C. Whatley

(Institute of Earth Studies, University of Wales, Aberystwyth, U.K.)

Artesiocythere artesica Krommelbein, 1975

1975 Artesiocythere artesica sp. nov., K. Krommelbein, Senckenberg. leth., 55, 469-470, pi. 5, figs. 16-17, text-figs. 7-8.

Holotype:

Type locality:

Figured specimens:

Diagnosis:

BMR (Bureau Mineral Resources) now called AGSO (Australian Geological Survey Organisation),

Canberrra no. CPC 13872; LV.

Borehole Tickalara-1, Great Artesian Basin, SW Queensland, Australia (long. 142°13'E, lat.

28°40'S), 247'0"-248'l " below surface, Allaru Mudstone, Rolling Downs Group; Albian-

Cenomanian.

AGSO nos. CPC 13872 (holotype, LV: PI. 22, 26, fig. 1; PI. 22, 28, figs. 1, 3), CPC 13873 (para-

type, RV: PI. 22, 26, figs. 2, 3; PI. 22, 28, fig. 2). Paratype from the same borehole as holotype but

from 276'3"-277'8!/2" below surface.

Artesiocythere with very coarsely reticulate ornament, thick shell and subpyriform shape; with apex

of dorsal margin below mid-height. Hinge robustly antimerodont. Radial pore canals straight; 10

anteriorly, 5 posteriorly, the latter concentrated at postero-ventral angle.

Explanation of Plate 22, 26

Figs. 1, LV, ext. lat. (holotype, CPC 13872, 630 /um long). Figs. 2, 3, RV (paratype, CPC 13873, 600 //m long): fig. 2, ext. lat.; fig. 3,

posterior ornament.

Scale A (200 /um; x95), figs. 1, 2; scale B (50 //m; x593), fig. 3.

Stereo-Atlas of Ostracod Shells 22, 27

Artesiocythere artesica (3 of 4)

Remarks: This monotypic genus was placed in the Progonocytheridae by Krommelbein (op. cit.) but it clearly

belongs in the Cytherideidae, Cytherideinae. The only somewhat similar taxon from the Australian

Cretaceous is Rostrocytheridea westraliensis (Chapman, 1917) of Neale (J. W. Neale, Spec. Pap.

Palaeont., 16, 39-40, pi. 2, figs. 1-2; pi. 6, fig. 4; pi. 7, figs. 1-3, 1975) but this species is more

elongate and has large posterior and postero-ventral spines. Although Kommelbein in the type

description refers to the hingement as ‘merodont/entomodont’, it is in fact, very robust

antimerodont.

Distribution: This species is known only from the Tickalara Borehole in SW Queensland, Australia.

Acknowledgements: We thank Dr M. A. Ayress (Department of Geology, The Australian National University,

Canberra) for photography of Krommelbein’s material.

Explanation of Plate 22, 28

Fig. 1, 3, LV (holotype, CPC 13872, 630 pm long): fig. 1, int. lat.; fig. 3, muse. sc. Fig. 2, RV, int. lat. (paratype, CPC 13873, 600 um

long).

Scale A (200 nm\ x95), figs. 1, 2; scale B (100 pm\ x294), fig. 3.

Stereo-Atlas of Ostracod Shells 22, 26

Artesiocythere artesica (2 of 4)

Artesiocythere artesica (4 of 4)

Stereo-Atlas of Ostracod Shells 22, 28

Stereo-Atlas of Ostraeod Shells 22 (8) 29-32 (1995) Allaruella australiensis (1 of 4)

595.337.14 (116.313+ 116.331) (943 : 163. 142.29) : 551 .35 + 552.52

ON ALLARUELLA AUSTRALIENSIS KROMMELBEIN

by Caroline A. Maybury, Robin C. Whatley & Sara Ballent

(Institute of Earth Studies, University of Wales, Aberystwyth, U.K.

& University of La Plata, Argentina)

Genus ALLARUELLA Krommelbein, 1975

Type-species (by original designation): Allaruella australiensis Krommelbein, 1975

Diagnosis: A medium, thick-shelled and heavily ornamented cytherurid. Anterior margin broadly and sym-

metrically rounded; posterior more bluntly so, with apex at about mid-height. Dorsal margin

sloping strongly towards posterior, over-reached, particularly in the LV by ornament. Ventral

margin with conspicuous oral concavity, overhung medianly by valve tumidity. End margins some-

what compressed. Eye tubercle large and prominent; internal ocular sinus small. Ornament coarsely

and very irregularly reticulate and with a series of large hollow tubercles situated sub-centrally,

postero-dorsally and postero-ventrally. Strong, almost crest-like vertical ribs occur just in front of

the sub-central tubercle, postero-ventrally and on the posterior marginal area. Hinge antimerodont

and strongly developed. Calcified inner lamella wide, especially anteriorly where there are (accord-

ing to Krommelbein) some 12-17 radial pore canals, with the lower number being characteristic of

the RV and the higher of the LV; 6 or 7 radial pore canals occur posteriorly.

Allaruella australiensis Krommelbein, 1975

1975 Allaruella australiensis gen. et sp. nov., K. Krommelbein, Senckenberg. leth., 55, 470-472, pi. 2, figs. 8-9, text-figs. 9-10.

Explanation of Plate 22, 30

Figs. 1, 9 LV, ext. lat. (holotype, CPC 13878, 630 /rm long). Fig. 2, 9 RV, ext. lat. (paratype, CPC 13879, 600 gm long).

Scale A (100 /tm; xl50), figs. 1-2.

Stereo-Atlas of Ostraeod Shells 22, 31

Allaruella australiensis (3 of 4)

Holotype:

Type locality:

Figured specimens:

Diagnosis:

Remarks:

Distribution:

A cknowledgements:

BMR (Bureau Mineral Resources) now called AGSO (Australian Geological Survey Organisation),

Canberra no. CPC 13878; 9 LV.

Borehole Tickalara-1, Great Artesian Basin, SW Queensland, Australia (long. 142°13'E, lat.

28°40'S), 247'0"-248' 1 " below surface, Allaru Mudstone, Rolling Downs Group, Albian-

Cenomanian.

AGSO nos. CPC 13878 (holotype, 9 LV: PI. 22, 30, fig. 1; PI. 22, 32, fig. 1), CPC 13879 (paratype,

9 RV: PI. 22, 30, fig. 2; PI. 22, 32, fig. 2). Paratype from same borehole and same level as

holotype.

As for the genus (presently monotypic).

The hinge, although described by Krommelbein (op. cit. , 471) as entomodont, is clearly

antimerodont. The fact that the illustrated paratype RV has a somewhat broken anterior hinge line

could be responsible for this error. The genus seems to be monotypic and not particularly closely

related to other taxa. Krommelbein suggested a similarity with Orthonotacythere Alexander, 1933

(C. I. Alexander, J. Paleont., 7, 199) but the latter genus is more quadrate to sub-rhomboidal in

shape. Other Mesozoic cytherurid genera, such as Trachycy there, Triebel & Klingler, 1959 (E.

Triebel & W. Klingler, Geol. Jb., 76, 343) are separated by a very large stratigraphical interval

(Lower to Middle Jurassic) and Trachycythere has an orderly double row of tubercles and is more

elongated with a different posterior margin. Some species of Eucytherura (Vesticytherura)

Griindel, 1964 emend 1981 (J. Griindel, Mber. dt. Akad. Wiss. Berl., 6, 747, 1964 and Z. geol.

Wiss., 9, 548, 1981) are somewhat similar but have a more sub-dorsal posterior margin and those

of Oligocythereis ( = Morkovenicythereis) Griindel, 1975 (J. Griindel, Z. geol. Wiss. , 3, 368) have

much less rugose ornament.

Known only from the Albian/Cenomanian of the Tickalara Borehole, SW Queensland, Australia.

We thank Dr M. A. Ayress (Department of Geology, The Australian National University,

Canberra) for photography of Krommelbein’s material.

Explanation of Plate 22, 32

Fig. 1, 9 LV, int. lat. (holotype, CPC 13878, 630//m long). Fig. 2, 9 RV, int. lat. (paratype, CPC 13879, 600 gm long).

Scale A (100 gm; x 150), figs. 1-2.

Stereo-Atlas of Ostracod Shells 22, 32

Allaruella australiensis (4 of 4)

Stereo-Atlas of Ostracod Shells 22, 30

Allaruella australiensis (2 of 4)

Stereo-Atlas of Ostracod Shells 22 (9) 33-36 (1995)

595.337.14 (118.144) (942 : 163. 138.36) : 551 .35

Arcacythere rugosa (1 of 4)

ON ARCACYTHERE RUGOSA MAJORAN sp. nov.

by Stefan Majoran

(Department of Marine Geology, Goteborg University, Sweden)

1979 Arcacythere sp.

1993 Arcacythere sp.

Holotype:

Type locality:

Derivation of name:

Figured specimens:

Arcacythere rugosa sp. nov.

K. G. McKenzie, in: B. J. Cooper (Ed.), Rep. Invest. Dept. Mines S. Aust., 50, 93, 94, pi. 1, fig. 9.

K. G. McKenzie, R. A. Reyment & E. R. Reyment, Revta esp. Paleont., 8, 93, pi. 4, fig. 1.

Department of Marine Geology, University of Goteborg, Sweden, no. DMGUG.Au. 68; LV.

Type section of the Blanche Point Formation, near Willunga, South Australia (lat. 35° 15' S, long.

138° 24' E). Late Eocene, Priabonian. Holotype collected 5 m above base of the Perkana Member

(dated by planktonic foraminifera as P16, see McGowran et al., 1992 in: D. R. Prothero & W. A.

Berggren (Eds.), Eocene-Oligocene Climatic and Biotic Evolution , Princeton University Press,

178-201).

Latin rugosa, ridged; alluding to the lateral ornament.

Department of Marine Geology, Goteborg University, nos. DMGUG.Au. 68 (holotvpe, adult LV:

PI. 22, 34, fig. 1), DMGUG.Au. 69 (adult car.: PI. 22, 34, fig. 2), DMGUG.Au. 70'(juv. A-l RV:

PI. 22, 36, fig. 3), DMGUG.Au. 73 (adult RV: PI. 22, 34, fig. 3), DMGUG.Au. 71 (adult RV: PI.

22, 36, fig. 1), DMGUG.Au. 72 (adult LV: PI. 22, 36, fig. 2).

Explanation of Plate 22, 34

Fig. 1, adult LV, ext. lat. (holotype, DMGUG.Au. 68, 420 pm long). Fig. 2, adult car., ext. dors. (DMGUG.Au. 69, 420 pm long).

Fig. 3, adult RV, ext. lat. (DMGUG.Au. 73, 415 long).

Scale A (100 /tm; x 165), figs. 1-3.

Stereo-Atlas of Ostracod Shells 22, 35

Arcacythere rugosa (3 of 4)

All specimens are from type locality: DMGUG.Au. 69, 73 from the Tuketja Member;

DMGUG.Au. 71, from the Gull Rock Member; and DMGUG.Au. 68, 70, 72 from the Perkana

Member. (The Blanche Point Formation is divided into the Tuketja, Gull Rock and Perkana

members in ascending stratigraphic order).

Diagnosis: A non-reticulate species of Arcacythere ornamented with conspicuously curved ridges running

from the mid-dorsal region towards the anterior and posterior margins. The ventromedian region

shows a curved horizontal ridge that forms a median lattice with ascending vertical, slightly

inclined ridges. Internal features as for genus.

Remarks: The lateral ornament distinguishes the new taxon from other species of Arcacythere (see Horni-

brook, 1952, Palaeont. Bull. Wellington, 18, 31-32; Whatley et al., 1982, J. Micropalaeontol. , 1,

1-11; Ayress, 1991, J. Micropalaeontol., 10, 223-226; McKenzie et al., 1993 (op. cit.), although

the lateral outline resembles A. chapmani Hornibrook, 1952 (op. cit.). The new species is very rare

in the Blanche Point Formation, only 19 specimens having been recovered, consisting of 15 adults

(one carapace and 14 valves) and 4 immature valves (A-l). There is no clear evidence of sexual

dimorphism among the adults.

Distribution: Presently known from the Tuketja, Gull Rock and Perkana members of the Blanche Point

Formation, South Australia (Late Eocene, Priabonian, Zone P16). Also from the Middle? Eocene,

below the Johanna River Greensand Member at Browns Creek, Victoria, and in the Browns Creek

Clays (Late Eocene) at Browns Creek (see McKenzie et al., 1993).

Explanation of Plate 22, 36

Fig. 1, adult RV., int. lat. (DMGUG.Au. 71, Alb pm long). Fig. 2, adult LV, int. lat., muse. sc. (DMGUG.Au. 72); Fig. 3, juv. A-l

RV, ext. lat. (DMGUG.Au. 70, 380 pm long).

Scale A (100 pm; x 165), figs. 1, 3; scale B (10//m; x565), fig. 2.

Stereo-Atlas of Ostracod Shells 22, 34

Arcacythere rugosa (2 of 4)

Arcacythere rugosa (4 of 4)

Stereo-Atlas of Ostracod Shells 22, 36

Stereo-Atlas of Ostracod Shells 22 (10) 37-40 (1995) Kuiperiana paravariesculpta (1 of 4)

595.337.14 (118.22) (420: 162.006.50 + 44:002.46): 551.35

ON KUIPERIANA PARAVARIESCULPTA MAYBURY sp. nov.

by Caroline A. Maybury

(Institute of Earth Studies, University of Wales, Aberystwyth, U.K.)

Kuiperiana paravariesculpta sp. nov.

1989 Kuiperiana variesculpta (Ruggieri); R. C. Whatley & C. Maybury in: J. Fourniguet, F. Trautmann, J.-P. Margerel, R. C. Whatley, C. Maybury

& M. T. Morzadec-Kerfourn, Geol. Fr., 1989 (1-2), 72 (list) ( non Loxoconcha variesculpta Ruggieri, 1962).

Holotype:

Type locality:

Derivation of name:

Figured specimens:

The Natural History Museum, London [BMNH] no. OS 14647, cr LV.

[Paratypes nos. OS 14648-14652],

Sample no. 29, Vicarage Pit, St. Erth, Cornwall, England (5°26'W, 50°10'N; Nat. Grid Ref. SW 556352);

Upper Pliocene.

Latin referring to the similarity of the new species to Kuiperiana variesculpta (Ruggieri, 1962) ( Palaeontogr .

ital., 56 (26), 58, pi. 7, figs. 12-13, text-fig. 13).

The Natural History Museum, London [BMNH] nos. OS 14647 (holotype, o’ LV: PL 22, 38, fig. 1), OS 14648

(paratype, cr RV: PL 22, 38, fig. 2), OS 14652 (paratype, 9 LV: PL 22, 38, fig. 3), OS 14651 (paratype, cr car:

PI. 22, 40, fig. 1), OS 14649 (paratype, cr LV: PI. 22, 40, Fig. 2), OS 14650 (paratype, o’ RV: PI. 22, 40, figs.

3, 4). All paratypes are from the same sample as the holotype, with the exceptions of paratype OS 14652 which

is from sample no. 23, but from the type locality and horizon (see C. A. Maybury, Taxonomy, Palaeoecology

and Biostratigraphy of Pliocene Benthonic Ostracoda from St. Erth and NW France, unpub. PhD thesis, Univ.

Wales, 1, 3-6, 1985 for further sample details) and paratype OS 14651 which is from Falleron, NW France

(1°45'W, 46°50'N) (see J.-P. Margerel, Les Foraminiferes du Redonien. Systematique, Repartition stratigrap-

hique, Paleoecologie, Nantes, 1, 8-26, 1968 for further sample details).

Explanation of Plate 22, 38

Fig. 1, o’ LV, ext. lat. (holotype, OS 14647, 510/rm long). Fig. 2, O’ RV, ext. lat. (paratype, OS 14648, 510^m long). Fig. 3, 9 LV,

ext. lat. (paratype, OS 14652, 410/um long).

Scale A (100 pm; xl23), figs. 1-3.

Stereo-Atlas of Ostracod Shells 22, 39 Kuiperiana paravariesculpta (3 of 4)

Diagnosis: A small to medium-sized, subelliptical Kuiperiana with an ornament of polygonal reticulae. Anterior margin

rounded and downturned; posterior margin rounded and upturned; dorsal margin straight, sometimes slightly

obscured by valve’s tumidity; ventral margin curved, but obscured posteriorly by a subrounded alar protuber-

ance. Eye spot smooth and connected with reticulae. RV hinge composed anteriorly of a comma-shaped socket

arching around a subovoid tooth and continuous with the median element, which is a smooth groove. The

posterior terminal element is a narrow bar with a frill-like dorsal edge. In the LV the anterior terminal element

is a comma-shaped tooth enclosing a small subovoid socket. The median element is a smooth bar communicating

with the anterior terminal tooth. The posterior terminal element is a comma-shaped socket and subovoid tooth.

Muscle scars an oblique row of 4 adductors with a ‘c’-shaped frontal open dorsally. Fulcral point between the

median adductors and frontal scar. The 2 mandibular scars are small and circular in outline.

Remarks: This species is similar in size to Kuiperiana variesculpta (Ruggieri) {op. cit.) and its ornament also appears

similar. As Ruggieri’s original illustrations are hand drawings and as I have been unable to contact Professor

Ruggieri I cannot regard the two species as conspecific. K. variesculpta seems, from the illustrations, to have a

prominent, strongly laterally compressed anterior margin rim with striate markings parallel to the margin. These

features are lacking in K. paravariesculpta. The species Whatley & Maybury referred to as K. variesculpta

(Ruggieri, 1962) (in: J. Fourniguet et al., op. cit.) is herewith assigned to K. paravariesculpta.

Distribution: Upper Pliocene deposits of St. Erth, Cornwall, England (sample nos. 1-4, 7, 10, 12, 14, 16, 18, 21, 23, 25-29)

and Upper Pliocene (Redonian) deposits of Apigne Borehole II, Beugnon (sample no. 1), Cricqueville-en-Bessin

(sample nos. 5, 9, 13), Falleron, L’Aubier, Le Bosq d’Aubigny, Le Temple du Cerisier, Palluau I (200-280, 380,

640 cm), Palluau II (480, 500-540, 580, >640 cm), Reneauleau, Reneauleau base, Saint-Jean-la-Poterie (sample

no. 1549.14) and a mixed sample. See Maybury (op. cit.) for further details of the British samples and for the

French, see Margerel (op. cit.), except for a description of the deposits at Cricqueville-en-Bessin, which may be

found in C. Pareyn, P. Brebion, E. Buge, R.-P. Carriol, A. Lauriat-Rage, Y. Le Calvez & J. Roman, Bull. Mus.

natn. Hist. nat. Paris, ser. 4, 5 (C, 4), 372-373, 1983.

Explanation of Plate 22, 40

Fig. 1, cr car., ext. dors, (paratype, OS 14651, 490 //m long). Fig. 2, o’ LV, int. lat. (paratype, OS 14649, 490 pm long). Figs. 3, 4, O’

RV (paratype, OS 14650, 550 pm long).

Scale A (100 /rm; xl23), figs. 1, 2; scale B (40 pm\ x307), figs. 3, 4.

Stereo-Atlas of Ostracod Shells 22, 38

Kuiperiana paravariesculpta (2 of 4)

Stereo-Atlas of Ostracod Shells 22 (11) 41-44 (1995) Cytheropteron bronwynae (1 of 4)

595.337.14 (119.9) (268 : 162.014.85): 551.353

ON CYTHEROPTERON BRONWYNAE JOY & CLARK

by Richard Jones & Robin C. Whatley

(Institute of Earth Studies, University of Wales, Aberystwyth, U.K.)

Cytheropteron bronwynae Joy & Clark, 1977

1977 Cytheropteron bronwynae sp. nov., J. A. Joy & D. L. Clark, Micropaleontology, 23, 140, PI. 2, figs. 1-3.

Type specimens:

Type locality:

Figured specimens:

Diagnosis:

Department of Geology and Geophysics, University of Wisconsin, Madison (UW): Holotype (UW 1597-

5a); paratypes (UW 1597-5b-1597-5d).

Core FL 198, 16-1, central Arctic Ocean (lat. 80°22.19'N, long. 172° 33.92' W), water depth 3198m;

Recent.

The Natural History Museum, London [BMNH] nos. 1995.1281 (9 RV: PI. 22, 42, fig. 1), 1995.1282 (9

LV: PI. 22, 42, fig. 2), 1995.1283 (O’ RV: PI. 22, 42, fig. 3), 1995.1284 (o* LV: PI. 22, 42, fig. 4),

1995.1285 (9 RV: PI. 22, 44, figs. 1, 5, 6), 1995.1286 (9 LV: PI. 22, 44, fig. 2), 1995.1287 (juv. LV: PI.

22, 44, fig. 3), 1995.1288 (9 car.: PI. 22, 44, fig. 4).

All specimens are from the Morris Jesup Rise, Arctic Ocean (lat. 85° 19.4' N, long. 14° W) on the ARK

VIII/3 (ARCTIC ’91) cruise.

Subovate with pronounced, smooth caudal process; apex just above mid-height. Anterior margin

narrowly rounded and bearing 5-6 strong marginal denticles, mainly above apex. Dorsal margin strongly

arched in RV with pronounced keel-like rib; less arched in LV. Ventral margins strongly convex, with

marked postero-ventral keel, especially in LV. Valve surface coarsely punctate with puncta orientated in

Explanation of Plate 22, 42

Fig. 1, 9 RV, ext. lat. (1995.1281, 700 ^m long). Fig. 2, 9 LV, ext. lat. (1995.1282, 700 long). Fig. 3, cr RV, ext. lat. (1995.1283,

700 long). Fig. 4, cr LV, ext. lat. (1995.1284, 700 pm long).

Scale A (200 pm\ xl20), figs. 1-4.

Stereo-Atlas of Ostracod Shells 22, 43 Cytheropteron bronwynae (3 of 4)

oblique rows and with oblique ribs originating in a postero-dorsal loop crossing valve behind alae.

Anterior third with subdued ornament. Ventral surface with parallel ribs and rows of puncta along

margin of postero-ventral keel. Alae pronounced; leading edge thick with ventro-lateral deep pit and

strong, backward-directed apical spine. Hinge antimerodont with a RV overlap except for the anterior

quarter of the hinge where the LV overlaps the RV.

Remarks: This deep water species of Cytheropteron co-exists with a number of morphologically similar forms of the

same genus in the Arctic Ocean, such as C. carolinae Whatley & Coles, 1987 (Revta esp. Micropaleont.,

19, 60), first described from DSDP Leg 94, and C. hamatum Sars, 1869 ( Forh . VidenskSelsk. Krist.,

1868, 172), first described from the Lofoten Islands and now recognised across the NE Atlantic. The

latter differs from the present species primarily by its more acutely tapering alae which possess a charac-

teristic second smaller spine on the training edge. C. carolinae, while similar in size and shape to females

of C. bronwynae, lacks marginal denticles on the anterior margin and has finer puncta on the dorsal alar

surface. C. alatum Sars, 1866 {Forh. VidenskSelsk. Krist., 1865, 81) has been compared to C. bronwynae

but is easily distinguished by its lack of ornamentation and considerably larger alar expansion. Sexual

dimorphism is exhibited in many Quaternary and Recent forms of Cytheropteron. It is expressed

morphologically in C. bronwynae in terms of the dimensions of the carapace and length of extension of

the alar spines. The shorter, higher forms are probably males and possess a shorter spine.

Distribution: C. bronwynae is the only known endemic deep water Arctic species. It is common at depths below 1000 m

and together with Krithe dominates ostracod assemblages in deep basins which are influenced by the

lower Arctic Ocean deep watermass between 2500 and 4500 m. C. bronwynae differs from other high

latitude species by being absent from the Greenland Sea and by its widespread occurrence in the Canadian

and Eurasian basins either side of the Lomonosov Ridge, a well known migrational barrier. A number of

Krithe and Cytheropteron species are absent or rare on the Canadian side of the ridge. The species

characterises glacial-age (cold) sediments.

Explanation of Plate 22, 44

Fig. 1, 5, 6, 9 RV (1995.1285, 685 pm long): fig. 1, ext. lat.; figs. 5, 6, ant. and post, hinge elements. Fig. 2, 9 LV, int. lat. (1995.1286,

685 pm long). Fig. 3, juv. LV, ext. lat. (1995.1287, 600 pm long). Fig. 4, 9 car. dors. (1995.1288, 700 pm long).

Scale A (200 pm\ xl20), figs. 1-4; scale B (100 ^m; x350), figs. 5, 6.

Stereo-Atlas of Ostracod Shells 22, 42

Cytheropteron bronwynae (2 of 4)

Stereo-Atlas of Ostracod Shells 22, 44

Cytheropteron bronwynae (4 of 4)

Stereo-Atlas of Ostraeod Shells 22 (12) 45-52 (1995) Cytherelloidea kayei (1 of 8)

595.337.3 (116.331 + 116.332+ 116.333.1) (420: 161.000.51 + 161.001.51): 551.35

ON CYTHERELLOIDEA KA YEI WEAVER

by David J. Horne1, Amnon Rosenfeld2 & Ian Slipper1

(x School of Earth Sciences, University of Greenwich, Chatham, U.K.;

2Geological Survey of Israel, Jerusalem)

Cytherelloidea kayei Weaver, 1982

1982 Cytherelloidea kayei sp. nov., P. P. E. Weaver, Palaeontogr. Soc. (Monogr.), 135 (562), 22-23, pi. 3, figs. 4-9.

1988 Cytherelloidea kayei Weaver; I. Jarvis, G. A. Carson, M. K. E. Cooper, M. B. Hart, P. N. Leary, B. A. Tocher, D. J. Horne

& A. Rosenfeld, Cret. Res., 9, 34, fig. 15 (h).

1988 Cytherelloidea kayei Weaver; I. P. Wilkinson, in: T. Hanai, N. Ikeya & K. Ishizaki (Eds.), Evolutionary Biology of Ostracoda,

Kodansha, Tokyo, pi. 1, fig. 9.

1990 Cytherelloidea kayei Weaver; D. J. Horne, I. Jarvis & A. Rosenfeld, in: R. Whatley & C. Maybury (Eds.), Ostracoda and Global

Events, Chapman & Hall, London, 127, pi. 2, fig. 1.

Holotype: The Natural History Museum, London [BMNH] no. OS 9464; 9 RV.

[Paratypes: BMNH nos. OS 9465-OS 9479],

Type locality: Bluebell Hill, Kent, SE England (lat. 51°20'N, long. 00°30'E), Lower Chalk Formation, Zig Zag

Chalk Member, 3.5 m below the Plenus Marls, Upper Cenomanian.

Explanation of Plate 22, 46

Figs. 1,5,9 RV (holotype, OS 9464, 595 gm long): fig. 1, ext. lat.; fig. 5, ext. vent. obi. Figs. 2, 4, 6, o* car. (paratype, OS 9465, 570 /urn

long): fig. 2, It. lat.; fig. 4, dors.; fig. 6, It. vent. obi. Fig. 3, 9 car. dors, (paratype, OS 9466, 600 am long).

Scale A (100 gm; x90), figs. 1-6.

Stereo-Atlas of Ostraeod Shells 22, 47 Cytherelloidea kayei (3 of 8)

Figured specimens: The Natural History Museum, London [BMNH] nos. OS 9464 (holotype, 9 RV: PI. 22, 46,

fig. 1, 5), OS 9465 (paratype, a car.: PL 22, 46, figs. 2, 4, 6), OS 9466 (paratype, 9 car.: PI. 22,

46, fig. 3), OS 14680 (9 RV: PI. 22, 48, fig. 1, 2), OS 14681 (9 LV: PI. 22, 48, figs. 3, 4; PI. 22,

52, fig. 5), OS 14682 (o* LV: PI. 22, 48, figs. 5, 6), OS 13134 (9 RV: PI. 22, 50, figs. 1, 2), OS 13133

(o- RV: PI. 22, 50, figs. 3, 4), OS 14683 (9 RV: PI. 22, 50, fig. 5), OS 13294 (9 RV: PI. 22, 52,

figs. 1, 2), OS 14684 (9 RV: PI. 22, 52, fig. 3, 4).

The holotype and paratypes were collected from the type locality and horizon by P. P. E.

Weaver. OS 14680-OS 14682 are from the Upper Cenomanian Zig Zag Chalk Member (Lower

Chalk Formation) at Abbots Cliff, near Folkestone, Kent, SE England (lat. 51°06'N, long.

01° 14'E), 4.6 m below the base of the Plenus Marls (sample ABC-1), collected by D. J. Horne.

OS 14683, OS 14684 are from the Coniacian Seaford Member (Upper Chalk Formation) at

Langdon Stairs, near Dover, Kent (lat. 51°08'N, long. 01°19'E), from samples D19 and D23

respectively (collected by D. J. Horne and A. Rosenfeld). OS 13294 is from the Turonian New Pit

Member (Middle Chalk Formation) at Akers Steps, near Dover (lat. 51°08'N, long. 01°17'E),

from sample AKS-C, collected by D. J. Horne and A. Rosenfeld.

Diagnosis: A species of Cytherelloidea with prominent, thick anterior marginal rib, an arcuate ventrolateral

rib, and posterodorsal and posteroventral swellings in both sexes. The anterior marginal rib runs

from below the anterior end of the relatively straight dorsal margin to about halfway along the

weakly sinuous ventral margin, the ventral segment being less swollen and tapering posteriorly. The

ventrolateral rib is swollen centrally and connects posteriorly, via a constricted section, to the

Explanation of Plate 22, 48

Figs. 1, 2, 9 RV (OS 14680, 585 gm long): fig. 1, ext. lat.; fig. 2, ext. vent. obi. Figs. 3, 4, 9 LV (OS 14681, 550//m long): fig. 3, ext.

lat.; fig. 4, ext. vent. obi. Figs. 5, 6, o* LV (OS 14682, 490 gm long): fig. 5, ext. lat.; fig. 6, ext. vent. lat.

Scale A (100 //m; x90), figs. 1-6.

Stereo-Atlas of Ostracod Shells 22, 46

Cytherelloidea kayei (2 of 8)

Stereo-Atlas of Ostracod Shells 22, 48

Cytherelloidea kayei (4 of 8)

Stereo-Atlas of Ostracod Shells 22, 49 Cytherelloidea kayei (5 of 8)

posteroventral swelling. The posterodorsal swelling is produced anteriorly into a short, tapering

diagonal rib which fades out in the direction of the central muscle scar pit. A short, swollen rib

inclined down towards the anterior is situated between the top of the central muscle pit and the

dorsal margin. A weak arcuate rib slightly swollen at each end, runs longitudinally between the

central muscle pit and the more prominent ventrolateral rib. Sexual dimorphism clear; males more

tapered posteriorly in lateral outline and with less prominent posterior swellings which in some

specimens tend to form a continuous posterior marginal rib. Well-preserved specimens show a fine

polygonal reticulation covering most of the external surfaces.

Remarks: Comparison of specimens of Cytherelloidea kayei from different parts of its stratigraphic range

show subtle differences in the development of the ribs. In particular, the subcentral rib running

longitudinally immediately below the muscle pit tends to be narrow and evenly developed in

Cenomanian specimens (e.g. PI. 22, 50, figs. 1, 2) but stratigraphically higher specimens show the

development of weak nodes or swellings at each end of this rib (e.g. PI. 22, 52, figs. 1, 2 (Turonian)

and PI. 22, 52, figs. 3, 4 (Coniacian)). In this respect some of the younger specimens resemble

Cytherelloidea binoda Clarke (Geol. Jb., A61, 45-46, pi. 1, figs. 1-5, 1982) from the Coniacian of

NW Germany, which we consider to be a distinct but closely related species. C. binoda differs from

C. kayei in that the rib connecting the two subcentral swellings is absent or at best very weakly

developed, and the dorsolateral and posterodorsal diagonal ribs are fused, giving the appearance of

a single, sinuous rib, tapering towards the anterior. Since these features are more easily distin-

guished in oblique ventrolateral views, we have followed Clarke’s (op. cit.) practice in providing

such illustrations is addition to the standard lateral views. C. binoda is also larger (length of adults

660-770 pm) than C. kayei (<650/wm long).

Explanation of Plate 22, 50

Figs. 1, 2, 9 RV (OS 13134, 570/zm long): fig. 1, ext. lat . ; fig. 2, ext. vent. obi. Figs. 3, 4, cr RV (OS 13133, 540 /jm long): fig. 3, ext.

lat.; fig. 4, ext. vent. obi. Fig. 5, 9 RV, int. lat. (OS 14683, 620 long).

Scale A (100 /^m; x90), figs. 1-5.

Stereo-Atlas of Ostracod Shells 22, 51 Cytherelloidea kayei (7 of 8)

Distribution: Marine Upper Cretaceous of the Anglo-Paris Basin: Cenomanian - Coniacian stages. In England,

the occurrence of C. kayei in the lowest Cenomanian is confirmed (Wilkinson, op. cit.); it has also

been reported (but not illustrated) in the Upper Albian Hunstanton Chalk Member by Wilkinson,

1990 (Cour. Forschlnst. Senckenberg, 123, 239-258).

Explanation of Plate 22, 52

Figs. 1, 2, 9 RV (OS 13294, 600 /^m long): fig. 1, ext. lat.; fig. 2, ext. vent. obi. Figs. 3, 4 (OS 14684, 625 um long): fig. 3, ext. lat.;

fig. 4, ext. vent. obi. Fig. 5, 9 LV, int. lat. (OS 14681, 550 fum long).

Scale A (100 am; x90), figs. 1-5.

Cytherelloidea kayei (6 of 8)

Cytherelloidea kayei (8 of 8)

Stereo-Atlas of Ostracod Shells 22, 50

Stereo-Atlas of Ostracod Shells 22, 52

Stereo-Atlas of Ostracod Shells 22 (13) 53-60 (1995) Semicytherura complanata (1 of 8)

595.337.14 (119.1 + 119.4+ 119.9) (485 : 161 .01 1.58 + 489 : 161.010.57 + 714 : 162.070.47 + 798 : 162.151.70): 551.351.

ON SEMICYTHERURA COMPLANATA

(BRADY, CROSSKEY & ROBERTSON)

by David J. Horne & Alan R. Lord

(School of Earth Sciences, University of Greenwich, Chatham

& Department of Geological Sciences,

University College London, England)

Semicytherura complanata (Brady, Crosskey & Robertson, 1874)

1874 Cytherura (?) complanata sp. nov., G. S. Brady, H. S. Crosskey & D. Robertson, Palaeontogr. Soc. (Monogr.), 1874, 194, pi. 11, figs. 19, 20.

1982 ‘Cytherura’ complanata Brady, Crosskey & Robertson; A. R. Lord, Sver. geol. Unders. Afh., C794, 138, 145.

1987 Semicytherura complanata (Brady, Crosskey & Robertson); T. M. Cronin in: N. R. Gadd (Ed.), Late Quaternary development of the Champlain

Sea Basin, Geol. Assoc. Canada, Special Publ., 20-21, pi. 3, figs. 7-9.

1987 Semicytherura sp., K. L. Knudsen & D. N. Penney, Danm. geol. Unders., B10, 54, pi. 2, figs. 5, 6.

1987 Semicytherura complanata (Brady, Crosskey & Robertson); T. M. Cronin & N. Ikeya, J. Micropalaeontol., 6 (2), 85, pi. 3, fig. 17.

Holotype : Not defined. No material in the Brady Collection, Hancock Museum, Newcastle-upon-Tyne; the Crosskey

Collection, Hunterian Museum, Glasgow has two poorly preserved RV, one broken (slide 610).

Type locality: Annochie, E Scotland (Nat. Grid. Ref. NK 104 532; lat. 57°34'20"N, long. 1°49'40''W). Original

material from this locality.

Figured specimens: Senckenberg Museum, Frankfurt, Germany nos. Xe 18047 (cr LV: PI. 22, 54, fig. 3), Skagen Borehole,

North Jutland, Denmark (lat. 57°46'N, long. 10°40'E), 115.14m; 18048 (cr car.: PI. 22, 56, fig. 1; PI.

22, 58, fig. 2), 18049 (9 RV: PI. 22, 58, fig. 4) and 18050 (O' LV: PI. 22, 54, fig. 1), Skagen Borehole,

Explanation of Plate 22, 54

Fig. 1, O' LV, ext. lat. (Xe 18050, 400 pm long). Fig. 2, 9 LV, ext. lat. (18051, 400 pm long). Fig. 3. O' LV, int. lat. (18047, 400 pm long).

Scale A (100 //m; xl50), figs. 1-3.

Stereo-Atlas of Ostracod Shells 22, 55 Semicytherura complanata (3 of 8)

119.19 m; 18051 (9 LV: PI. 22, 54, fig. 2), 18052 (9 RV: PI. 22, 56, fig. 2) and 18053 (9 car.: PI. 22, 58,

fig. 3), Skagen Borehole, 121.34 m; 18054 (9 RV: PI. 22, 56, fig. 3; PI. 22, 58, fig. 1), Skagen Borehole,

125.49 m; 18055 (9 RV: PI. 22, 58, fig. 5), Skagen Borehole, 127.34 m; all from the Pleistocene (Weich-

selian). Xe 18058 (9 LV: PI. 22, 60, figs. 1, 2) and 18059 (9 RV: PI. 22, 60, figs. 3, 4), Moltemyr Borehole,

Sweden (lat. 58° 26' 45" N, long. 1 1° 32' 36" E), 6.10-6.20 m (see Lord, op. cit., 1982); Pleistocene (Weich-

selian). The Natural History Museum, London [BMNH], Palaeontology Dept. no. OS 13355 (9 RV: Text-

fig. 1), Pt. Originaux, Quebec, Canada (lat. 47°29'N, long. 70°01'W), T. Cronin Colin., c. 10,000 BP;

Zoology Dept. no. 1988.317 (9 LV and appendages: Text-figs. 2a-c), BARNES 58-60, Beaufort Sea,

Alaska (lat. 70°36.69'N, long. 150°24.7'N), E. Brouwers Colin.; Recent.

Diagnosis: A species of Semicytherura lacking a caudal process and characterised by subquadrate outline, a rim

running around all margins, and ornament consisting of a primary reticulation of fine ribs posteriorly

passing in the mid-valve area into an even punctation (secondary reticulation) which dominates the

anterior half of the valve. Weakly dimorphic.

Remarks: A neotype should probably be defined from the material figured here, as recent investigations in the type

area of Annochie did not yield ostracods (A. Hall & J. Jarvis, Quaternary News/., 59, 5-7, 1989) and the

only specimens in the Crosskey Collection are poorly preserved. We would, however, prefer a neotype to

be defined from Scottish material.

The species is unusual for Semicytherura in lacking a caudal process but features of the marginal zone

(Text-figs. 1, 2a) and the appendages (Text-figs. 2b, 2c; Recent, Beaufort Sea, Alaska) confirm the generic

identification. Some variation in the strength of development of ornament is evident in our material and

in published illustrations but the significance is not clear. The ornamental pattern is unusual; posteriorly,

a network of fine primary ribs forms cells which enclose ‘blind’ puncta, but this changes in mid-valve

along a distinct line (PI. 22, 58, fig. 2) with the primary ribbing fading so that the secondary punctate orna-

ment dominates the anterior part of the valve and the puncta appearing ‘open’. Right valves show a small

postero-ventral marginal alar protuberance.

Explanation of Plate 22, 56

Fig. 1, cr car., ext. lat. (Xe 18048, 375 pm long). Fig. 2, 9 RV, ext. lat. (18052, 315pm long). Fig. 3, 9 RV, int. lat. (18054, 400 pm

long).

Scale A (100 pm\ x 160), figs. 1, 2; scale B (100 pm; x 150), fig. 3.

Stereo-Atlas of Ostracod Shells 22, 54

Semicytherura complanata (2 of 8)

Stereo-Atlas of Ostracod Shells 22, 56

Semicytherura complanata (4 of 8)

Stereo-Atlas of Ostracod Shells 22, 57 Semicytherura complanata (5 of 8)

Text-fig. 1. 9 RV, ext. lat. in transmitted light (OS 13355, 400 long). Text-fig. 2. 9 LV (1988.317, 400 long). 2a, ext. lat. in transmitted light;

2b, antenna; 2c, antennula.

Scale A (lOO^m), text-figs. 1, 2a; scale B (100 gm), text-figs. 2b, c.

Explanation of Plate 22, 58

Fig. 1, 9 RV, ant. hinge (Xe 18054). Fig. 2, cr car., detail mid-valve (18048). Fig. 3, 9 car., dors. (18053, 400 pm long). Fig. 4, 9 RV,

‘open’ pores, ant. mid-valve (18049, 400 pm long). Fig. 5, 9 RV, ‘closed’ pores, post, mid-valve (18055, 350 pm long).

Scale A (20 pm; x700), figs. 1, 2, 5; scale B (100 /rm; x 150), fig. 3; scale C (lO/tm, x2100), fig. 4.

Stereo-Atlas of Ostracod Shells 22, 59 Semicytherura complanata (7 of 8)

A cknowledgements:

Drs E. M. Brouwers (USGS, Denver) and T. M. Cronin (USGS,

Reston) kindly provided material and data from Alaska and

eastern North America respectively. K. L. Knudsen (Aarhus,

Denmark) generously supplied Danish and Swedish material

figured here, Miss T. J. Paramor (UCL) prepared material and Mr

J. Davy (UCL) prepared the micrographs.

Text-fig. 3. Distribution of S. complanata: Late Pliocene (Alaska), Pleistocene

and Holocene. Living in Beaufort Sea, Alaska. Widespread coldwater, Arctic

species. Known fossil from NW Europe, eastern N America, Svalbard, Green-

land, Alaska and Japan.

Explanation of Plate 22, 60

Fig- 1, 9 LV, ext. lat. (Xe 18058, 400 pm long). Fig. 2, detail mid-dorsal area (18058). Fig. 3, 9 RV, ext. lat. (18059, 400 pm long).

Fig. 4, detail mid-dorsal area (18059).

Scale A (100 //m; xl50), figs. 1, 3; scale B (20y«m; x700), figs, 2, 4.

-v Vf,'

, e .... ■

• • • ■“ " ^

O M 'Hv'^;

' - > - w ^ "

- . ‘ . ,,. jyji

Stereo-Atlas of Ostracod Shells 22, 58

Semicytherura complanata (6 of 8)

Stereo-Atlas of Ostracod Shells 22, 60

Semicytherura complanata (8 of 8)

Stereo-Atlas of Ostraeod Shells 22 (14) 61 (1995)

595.336.21 (113.333) (768: 162.089.35): 552.351 +552.54

Poloniella schallreuteri (1 of 1)

non 1964

non 1983

1994

Remarks:

ON POLONIELLA SCHALLREUTERI LUNDIN nom. nov.

by Robert F. Lundin

(Arizona State University, Tempe, U.S.A.)

Poloniella schallreuteri nom. nov.

Poloniella (Parapoloniella) adamczaki sp. nov., H. Jordan, Freiberger ForschHft. , C170, 46-47.

Poloniella adamczaki sp. nov., B. Zbikowska, Palaeont. pot., 44, 42-43.

Poloniella adamczaki sp. nov., R. F. Lundin, Stereo-Atlas Ostraeod Shells, 21, 111-114.

Drs Helga Uffenorde (University of Gottingen) and Roger Schallreuter (University of Hamburg) have both

kindly informed me that I created a primary homonym when I named a new species Poloniella adamczaki

(Lundin, 1994). That name is occupied by Poloniella adamczaki Zbikowska, 1983 which is in turn preoccupied

by Poloniella (Parapoloniella) adamczaki Jordan, 1964. I hereby replace the 1994 junior primary homonym

with the new name Poloniella schallreuteri in recognition of the many contributions Dr Schallreuter has made

to our knowledge of ostracods.

BPC BLACKPOOL LTD

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this Publication and wish every success

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Stereo- At las of Ostracod Shells: Vol. 22, Part 1

CONTENTS

Back

On Baltocyamus primarius Meidla gen. et sp. nov.; by T. Meidla.

On Dizygopleura landesi Roth; by R.F. Lundin.

On Longiscella grandis (Jones & Holl); by L.E. Petersen & R.F. Lundin.

On Microcheilinella gigas Birkmann & Lundin sp. nov. ; by H. Birkmann &

R. F. Lundin.

On Ordovizona immanis Becker; by G. Becker.

On Inversibolbina lehnerti Schallreuter gen. et sp. nov.; by R.E.L. Schallreuter.

On Artesiocythere artesica Krommelbein; by C.A. Maybury & R.C. Whadey.

On Allaruella australiensis Krommelbein; by C.A. Maybury, R.C. Whatley &

S. Ballent.

On Arcacythere rugosa Majoran sp. nov.; by S. Majoran.

On Kuiperiana paravariesculpta Maybury sp. nov.; by C.A. Maybury.

On Cytheropteron bronwynae Joy & Clark; by R. Jones & R.C. Whatley.

On Cytherelloidea kayei Weaver; by D.J. Horne, A. Rosenfeld & I. Slipper.

On Semicytherura complanata (Brady, Crosskey & Robertson); by D.J. Horne &

A.R. Lord.

On Poloniella schallreuteri nom. nov.; by R.F. Lundin.

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