A Stereo-Atlas of Ostracod Shells edited by J. Athersuch, D. J. Horne, D. J. Siveter, and J. E. Whittaker Volume 19, Part 1; 31st July, 1992 Published under the aegis of the British Micropalaeontological Society, London ISSN 0952-7451 Editors Dr J. Athersuch, StrataData Ltd., 16 Ottershaw Park, Ottershaw, Surrey KT16 OGQ. Dr D.J. Horne, School of Earth Sciences, Thames Polytechnic, Walburgh House, Bigland Street, London El 2NG. Dr David J. Siveter, Department of Geology, The University, Leicester LEI 7RH. Dr J.E. Whittaker, Department of Palaeontology, British Museum (Natural History), Cromwell Road, London SW7 5BD. Editorial Board Dr J.-P. Colin, Esso Production Research - European, 213 Cours Victor Hugo, 33321 Begles, France. Dr MA. Ayress, Department of Geology, Australian National University, G.P.O. Box 4, Canberra, ACT 2601, Australia. Dr W. Hansch, Ernst-Moritz-Arndt Universitat, Sektion Geologische Wissenschaften, F.L.-Jahnstr. 17a, 2200 Greifswald, Germany. Prof. R. Lundin, Department of Geology, Arizona State University, Tempe, Arizona 85287-1404, U.SA.. Dr R.E.L. Schallreuter, Universitat Hamburg, Geologisch-Palaontologisches Institut, Bundesstrasse 55, D 2000 Hamburg 13, Germany. Prof. N. Ikeya, Institute of Geosciences, Shizuoka University, Shizuoka 422, Japan. Officers of the British Micropalaeontological Society Chairman Professor M.B. Hart, Department of Geological Sciences, Polytechnic South West, Drake Circus, Plymouth, Devon PL4 8AA. Secretary Dr J.B. Riding, British Geological Survey, Keyworth, Nottingham NG12 5GG. Treasurer Dr I.P. Wilkinson, British Geological Survey, Keyworth, Nottingham NG12 5GG. Journal Editor Dr M.C. Keen, Department of Geology, The University, Glasgow G12 8QQ. Newsletter Editor Dr D.J. Shipp, Simon- Robertson, T/n-y-Coed, Llanrhos, Llandudno, Gwynedd LL30 ISA. Conodont Group Chairman Dr J.J. Stone, Department of Geology, Trinity College, Dublin 2, Ireland. Conodont Group Secretary Dr S.J. Tull, Cambridge Arctic Shelf Programme, West Building, Gravel Hill, Huntingdon Road, Cambridge CB3 0DJ. Foraminifera Group Chairman Dr H.W. Bailey, PaleoServices Ltd., Unit 15, Paramount Industrial Estate, Sandown Road, Watford WD2 4XA. Foraminifera Group Secretary Dr S.R. Packer, Millenia Stratigraphic Consultants, Unit 3, Weyside Park, Newman Lane, Alton, Hampshire GU34 2PJ Ostracod Group Chairman Dr N.R. Ainsworth, PaleoServices Ltd., Unit 15, Paramount Industrial Estate, Sandown Road, Watford WD2 4XA Ostracod Group Secretary Dr I.D. Boomer, School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ. Palynology Group Chair Dr R.J. Davey, The Robertson Group pic, T/n-y-Coed, Llanrhos, Llandudno, Gwynedd LL30 ISA. Palynology Group Secretary Dr A. McNestry, British Geological Survey, Keyworth, Nottingham NG12 5GG. Calcareous Nannofossil Group Chairman Dr L.T. Gallagher, Paleo Services, Unit 15, Paramount Industrial Estate, Sandown Road, Watford WD2 4XA. Calcareous Nannofossil Group Secretary Dr N.M. Hine, British Geological Survey, Keyworth, Nottingham NG12 5GG. Instructions to Authors Contributions illustrated by scanning electron micrographs of Ostracoda in stereo-pairs are invited. Format should follow the style set by the papers in this issue. Descriptive matter apart from illustrations should be cut to a minimum; preferably each plate should be accompanied by only one page of text. Blanks to aid in mounting figures for plates may be obtained from any one of the Editors or Editorial Board. Completed papers should be sent to one of the Editors. All contributions submitted for possible publication in the Stereo- Atlas of Ostracod Shells are reviewed by an appropriate international specialist. The front cover shows a male left valves of Palmoconcha guttata (Norman, 1865) "normal form" (upper) and "granulata" form of Sars, 1866 (lower). Both Recent, from off Sunderland, NE England and Isle of Bute, SW Scotland, respectively. Hancock Museum, Newcastle-upon-Tyne, nos. 1.20.14 and 1.20.15. Photographed by J.E. Whittaker. Stereo-Atlas of Ostracod Shells 19 (1) 1-4 (1992) Cytheropteron byfieldense (1 of 4) 595.337.14 (116.213) (420: 162.002.52 + 003.56 + 44: 161.004.44): 551.351 +552.52 ON CYTHEROPTERON BYFIELDENSE BOOMER & BODERGAT sp. nov. by Ian Boomer & Anne-Marie Bodergat (University of East Anglia, Norwich, England & Universite Claude Bernard, Lyon, France) Cytheropteron byfieldense sp. nov. 1967 Cytheropteron byfieldensis (s/c) sp. nov. R. A. Field, Unpublished Ph.D. Thesis Univ. of London, 226, pi. 23, figs. 1-12 ( nom . nud.). Holotype. Type locality: Derivation of name: Figured specimens: British Museum (Natural History) No. OS 13698; 9 LV. Middle Toarcian, Byfield, Northamptonshire, lat. 52°12'N; long. 1°20'W (Grid Ref. SP 4535 2564). The type level is equivalent to the lowest 15 cm of Bed A, Barnard, 1950 (Q. Jl. geol. Soc. Lond., 106, 1-3) just above Lower Cephalopod bed. With reference to the type locality. British Museum (Natural History) numbers: OS 13695 (o* LV: PI. 19, 2, fig. 1), OS 13696 (9 LV: PI. 19, 2, fig. 2), OS 13697 (9 RV: PL 19, 2, fig. 4), OS 13698 (9 LV: PI. 19, 4, fig.l), OS 13699 (9 car: PL 19, 4, fig. 2), OS 13700 (A-l RV: PI. 19, 4, fig. 3), OS 13701 (9 RV: PI. 19, 4, fig. 4), Universite Claude Bernard, Lyon No. FSL 171058 (9 RV: PI. 19, 2, fig. 3). OS 13695, 13698, 13700 and 13701 from type locality and level; OS 13696, 13697 and 13699 from the Hildoceras bifrons Zone, Ilminster, Somerset, lat. 55°55'0"N, long. 2°55'0"W; FSL 171058 from the Hildoceras bifrons Zone, Penne, Quercy, France, lat. 44°26'24''N, long. 1°44'0"E. Explanation of Plate 19, 2 Fig. 1, 2.17 mm long): fig. 1, ext. It. lat.; fig. 2, ext. dors.; fig. 3, ext. vent.; fig. 4, ext. post. Scale A (250//m, x35), figs. 1-3; scale B (250 ttm, x48), fig. 4. Stereo-Atlas of Ostracod Shells 19, 7 Pejonesia sestina (3 of 4) Univ. Press). However, Paradabashanella does not apparently have an anterior beak; it does not appear to be present either in Shu’s reconstruction or in his photographs; indeed, the anterior side of Paradabashanella seems to be distinctly rounded. Further- more, Paradabashanella lacks the typical ridge that borders the dorsum in Pejonesia. This feature occurs not only in the holotype but also on the other specimens of Pejonesia and thus cannot be regarded as accidental distortion of the carapace. Shu has “a lot of carapaces or valves” at his disposal and did not mention this feature as a characteristic of Paradabashanella; thus, it is considered as a distinguishing feature between the two genera. Dabashanellids were described as univalved ostracods by Shu (op. cit., 1990) and Melnikova (In: Melnikova, L.M. & Mambetov, A.M ., Paleont. Zh. , 57-63, 1990), both of whom erected a new Order level taxon for this group. Pejonesia, too, lacks a defined “hinge”; nevertheless, I do not follow Shu’s and Melnikova’s concept because this development is regarded as an evolutionary trend rather than a feature for taxonomic differentiation at Ordinal level (Hinz, Arch. Geschk., 2, 231-234, 1991). In his 1990 paper Shu (op. cit.) stated that a primary phosphatic shell substance was characteristic of dabashanellids and included this feature in their diagnosis. Pejonesia clearly appears to be related to the later group of ostracods; however, as it comes from phosphorites (of the Georgina Basin), this fact excludes reliable statements about the true nature of the composition of its shell. Together with the uncertainty about the presence of a doublure, this prevents a firm assignment of Pejonesia to either phosphatocopinid or bradorinid ostracods, two groups which have been separated at ordinal taxonomic level by Muller (In: Bate, R.H., Robinson, E. & Sheppard, L.M. (eds.), Fossil and Recent Ostracods, 276-304, 1982, Brit. Micropal. Ser.; Ellis Harwood, Chichester). In Paradabashanella the presence of a multilayered shell points to the occurrence of secondary phosphatisation, as indeed does the presence (?) of what Shu (op. cit.) assumed were eggs in Dabashanella Shu. Notwithstanding such questions, it still remains unclear which features enabled Shu to differentiate taxa at the specific level. Pejonesia sestina (Fleming, 1973) 1971 Mononotelia sp. P.J.G. Fleming, in: Hill, D., Payford, G. & Woods, J.T., Cambrian fossils of Queensland, 28, pi. 14, figs. 2-4, Qd. Palaeontogr. Soc., Brisbane. 1973 Mononotelia sestina sp. nov., P.J.G. Fleming, Pubis geol. Surv. Qd, 356, 6, pi. 1, figs. 5-9, pi. 3, fig. 1, text-figs. A3-5. Holotype: Type locality: Figured specimens: Diagnosis: Distribution: Commonwealth Palaeontological Collections, Bureau of Mineral Resources, Canberra, Australia (CPC), no. 19781; carapace. About 1.6 km N 20° E of Mt. Murray, on Chatsworth Station, Duchess phosphorite field, Queensland, Australia; approx, lat. 21°47'S, long. 139°59'E. This is Bureau of Mineral Resources locality D640, Monastry Creek Phosphorite Member, Beetle Creek Formation, Late Templetonian, middle Cambrian. Commonwealth Palaeontological Collections, Bureau of Mineral Resources, Canberra, Australia (CPC) nos. 19781 (holotype, car.: PI. 19, 6, figs. 1-4), 23255 (car.: PI. 19, 8, figs. 1-4). Both from the type locality. Species of Pejonesia up to 2.2 mm long. In other respects as for the genus; Pejonesia is currently monotypic. Known only from the middle Cambrian of the Duchess phosphorite field, Queensland, Australia. Explanation of Plate 19, 8 Figs. 1-4, car. (paratype, CPC 23255, 2.1 mm long): fig. 1, ext. rt. lat.; fig. 2, ext. dors.; fig. 3 ext. vent.; fig. 4, ext. ant. Scale A (250 pm, x35), figs. 1-3; scale B (250 ^tm, x42), fig. 4. Stereo-Atlas of Ostracod Shells 19, 6 Pejonesia sestina (2 of 4) Stereo-Atlas of Ostracod Shells 19, 8 Pejonesia sestina (4 of 4) Stereo-Atlas of Ostracod Shells 19 (3) 9-12 (1992) Tubupestis tuber (1 of 4) 595.33.330 (113.23) (943 : 163.139.22): 551.351 ON TUBUPESTIS TUBER HINZ & JONES gen. et sp. nov. by Inglelore C. U. Hinz & Peter J. Jones (University of Bonn, Germany & Bureau of Mineral Resources, Canberra, Australia) Genus TUBUPESTIS gen. nov. Type-species: Tubupestis tuber sp. nov. From Latin tuber, tubercle, and pestis, plague; fancied resemblance of the lateral surface. Gender, feminine. Hesslandonid with equivalved, amplete carapace. Outline approximately semicircular, with gentle retral (posterior) swing in larger instars. Maximum length within half of valve. “Hinge” lines straight. Interdorsum fairly broad, mostly parallel-sided, tuberculate; “hinge-lines” converge only over a short distance near antero- and posterodorsal corners, both of which have upwardly directed spines. Free margin evenly developed, with doublure on inner side. Distinct free marginal ( = “adentral”) area absent, but carapace is somewhat flattened in antero- and posterodorsal regions. Maximum convexity of valve occurs anterodorsally. “Lobation” consists of nodes of different sizes and shape. Most prominent nodes/nodal complexes are those situated anterodorsally (1-3 nodes) and centrodorsally. Ventrally and posteriorly smaller and more widely spaced nodes/tubercles are arranged in rows approximately parallel to ventral margin. Original shell composition probably phosphatic. Tubupestis possesses the characters of a typical hesslandonid (Phosphatocopina) with respect to its phosphatic shell, and the presence of an interdorsum and doublure. The interdorsum of Tubupestis has parallel borders over most of its length, unlike that of Ulopsis Hinz, 1991 ( Stereo-Atlas Ostracod Shells, 18, 69-72) which has gently and continuously convex borders. Tubupestis displays several ontogentic changes: in particular, its lateral outline, which is amplete and horizontally elongate in juvenile stages, gradually becomes purse-shaped with a slight retral swing; nodes/tubercles become coarser and may be present on the interdorsum. Tubupestis is distinct from all other known phosphatocopinids in the characteristic arrangement of its lateral nodes/tubercles. Explanation of Plate 19, 10 Figs. 1, 2, car. (holotype, CPC 23158, 1.56 mm long): fig. 1, ext. rt. lat.; fig. 2, ext. dors. Fig. 3, incomplete, slightly compressed car., ext. It. lat. (CPC 23159 1.46 mm long). Scale A (250 pm, X42), figs. 1, 2; scale B (250 pm, x45), fig. 3. Derivation of name: Diagnosis: Remarks: Stereo-Atlas of Ostracod Shells 19, 1 1 Tubupestis tuber (3 of 4) Tubupestis shows superficial similarity to Neoduibianella Shu, 1990 (Cambrian and Lower Ordovician Bradoriida from Zhejiang, Hunan and Shaanxi Provinces, 54, Northwest Univ. Press), a Chinese genus which has distinct but (in contrast) irregularly arranged nodes on a reticulate surface. Well preserved specimens of Tubupestis tuber have a smooth outer surface, and occur together with other, definitely reticulate taxa. We regard Neoduibianella as congeneric with Duibianella Shu (op. cit., 52, 53): the outer surfaces of both taxa have a similar distribution of nodes and the absence in Duibianella of a similar microsculpture to that of Neoduibianella is probably due to poor preservation. As Duibianella has page priority, it is considered to be the senior synonym and the name we, as revising authors, prefer to use. Shu (op. cit., 52) referred the Duibianellidae (a family introduced by him to include Duibianella and Neoduibianella) to the Beyrichonacea Ulrich & Bassler 1931. By doing this, he thus implied that hesslandonid characters, such as a doublure and an interdorsum, are not found in the Duibianellidae. Tubupestis tuber sp. nov. 1980 New pustulose genus, P.J. Jones & K.G. McKenzie, Alcheringa, 4, 205. Derivation of name: Holotype: Type locality: Figured specimens: Diagnosis: Distribution: From Latin tuber, a tubercle; referring to the tuberculate outer surface of the valve. Commonwealth Palaeontological Collections, Bureau of Mineral Resources, Canberra, Australia (CPC) no 23158; carapace. About 1.6 km N 20° E of Mount Murray, on Chatsworth Station, Duchess phosphorite field, Queensland, Australia; approximately lat. 21°47'S, long. 139°59'E. This is Bureau of Mineral Resources locality D640. Monastry Creek Phosphorite Member, Beetle Creek Formation; Ptychagnostus gibbus Zone, later Templetonian, middle Cambrian. Commonwealth Palaeontological Collections, Bureau of Mineral Resources, Canberra, Australia (CPC) nos. 23158 (holotype, car.: PI. 19, 10, figs. 1, 2; PI. 19, 12, figs. 1, 2), 23159 (incomplete car.: PI. 19, 10, fig. 3), 23160 (car.: PI. 19, 12, fig. 3), 23161 (RV: PI. 19, 12, fig. 4). All of the figured specimens are from the type locality. Species of Tubupestis up to 2.6 mm in length. In other respects as for the genus; Tubupestis is currently monotypic. Known only from two early middle Cambrian localities of the type region, Duchess (4-mile geological series sheet F/54-6), Queensland, Australia. Unfigured specimens (CPC 19744-19746), also from BMR locality D640 ( = locality LI 13 of Queensland Museum), were listed by Jones & MacKenzie (1980, op. cit., 205) as “a new pustulose genus”. Explanation of Plate 19, 12 Figs. 1, 2, car. (holotype, CPC 23158, 1.56 mm long): fig. 1, ext. post.; fig. 2, ext. ant. Fig. 3, car. ext. rt. lat. (CPC 23160, 0.73 mm long). Fig. 4, RV, int. lat. (CPC 23161, 0.79 mm long). Scale A (100 pm, x46), figs. 1, 2; scale B (100 pm, xl02), fig. 3; scale C (100 /tm, x70), fig. 4. Stereo-Atlas of Ostracod Shells 19, 10 Tubupestis tuber (4 of 4) Tubupestis tuber (2 of 4) Stereo-Atlas of Ostracod Shells 19, 12 Stereo-Atlas of Ostracod Shells 19 (4) 13-16 (1992) Semillia pauper (1 of 4) 595.33.330 (1 13.23) (943 : 163.139.22): 551.351 ON SEMILLIA PAUPER HINZ gen. et sp. nov. by Inglelore C. U. Hinz (University of Bonn, Germany) Genus SEMILLIA gen. nov. Type-species: Semillia pauper sp. nov. From Latin semi- and elliptica; with reference to the shape of the valves in lateral view. Gender, feminine. Phosphatocopinid, carapace semieliiptical, subamplete. Dorsal margin in lateral view straight, except for slightly raised cardinal corners. Maximum length of valves at dorsal margin. Interdorsum very broad, with parallel edges that converge only near cardi- nal corners, both of which have upwardly directed processes. Width of interdorsum about one-third of entire width of carapace. Maximum convexity of carapace occurs just behind mid-length. Free margin evenly developed, distinct marginal ( = “adventral”) area lacking. Valves with narrow doublure. Four extremely weak nodes occur in the anterior half of the dorsal part of the valve. Lateral surface of valve smooth. The ventral morphology of the dosed carapace of the paratype (PI. 19, 16, fig. 3) is quite different from that of the holotype (PI. 19, 14, fig. 3). The paratype shows some sort of overlapping of the right valve by the left valve in the anteroventral portion of the carapace, behind which there is a distinct gap between the two valves. The ventral margin of the right valve of the paratype is slightly damaged, but not to such an extent as to explain the distinct gap. Both holotype and paratype come from the same sample, are comparatively large (length: 2.6 mm and 2.3 mm respectively) and, except for their ventral development, they agree in all available characters. It is presently uncertain whether these ventral differences represent a possible case of sexual dimor- phism within a single species or whether they reflect different species. It is preferred to regard the specimens as one species until further studies, based on a much larger amount of material, indicate otherwise. With its faintly nodose dorsal part of the valve, Semillia is similar to the middle Cambrian Hesslandona trituberculata Griindel (Freiberger ForschHft., C363, 57-73, 1981), which is characterised by three dorsal nodes. However, that species differs from Semillia in the number and arrangement of its nodes (with the third node being in the posterodorsal field) and by the development of its cardinal spines. H. trituberculata has a short, almost vertical anterior cardinal spine and a posterior cardinal spine which is Derivation of name: Diagnosis: Remarks: Explanation of Plate 19, 14 Figs. 1-4, car. (holotype, CPC 23253, 2.6 mm long): fig. 1, ext. It. lat.; fig. 2, ext. dors.; fig. 3, ext. vent.; fig. 4, ext. ant. Scale A (250/rm, x33), fig. 1; scale B (500 //m, x25), figs. 2, 3; scale C (250 pm, x44), fig. 4. Stereo-Atlas of Ostracod Shells 19, 15 Semillia pauper (3 of 4) large and broadly curved towards the posterior. Such differentiation in the cardinal regions is not present in Semillia. Further- more, the general outline of the valve in lateral view differs between the two taxa. According to Muller ( Neues Jb. Geol. Palaont. Abh., 121, 22, 1964), adult stages of the upper Cambrian Hesslandona necopina are characterised by having three nodes. However, it should be noted that Muller documented this species exclusively from what I regard to be larval stages, specimens whose maximum length is slightly greater than 1 mm. Indeed, the holotype of Hesslandona necopina (Muller, op. cit., PI. 1, fig. 6) is comparatively small (only about 0.5 mm long) and lacks any sculpture. Furthermore, all but one of Muller’s illustrated specimens come from the Olenus Zone; his largest specimen, which has nodes (Muller, op. cit., PL 1, fig. 2), was discovered from the much younger Peltura Zone and the conspecific nature of this specimen and the other specimens of H. necopina is rather questionable. Differences between this largest specimen of supposed H. “necopina” (Muller, op. cit., PI. 1, fig. 2) and Semillia include the number and distribution of nodes and the morphology of the free margin. In H. “necopina” the nodes are not in a line (the third node lies in the posterodorsal field, as in H. trituberculata) and the posteroventral margin is distinctly recessed. By contrast, in Semillia the nodes are restricted to the anterior half of the dorsal region and the free margin is evenly curved. Contrary to both the H. “necopina” specimen mentioned above and H. trituberculata, Semillia pauper has an extremely broad interdorsum, in which the valves themselves are incorporated at converging ends. As a consequence of this design, closure of the valves in Semillia inevitably resulted in a raising up of the dorsal ends of the valves; by contrast, opening of the carapace made the cardinal corners dip lower (Hinz, in press). In Hesslandona, the parallel edges of the interdorsum can be traced from the anterior to the posterior end of the carapace (In: Schram, F. R., Crustacean phytogeny, fig. 1 A, 1981 , Balkema, Rotterdam); with such an architecture, movements of the valves have much less effect on the flexibility of the dorsal area. Derivation of name: Holotype: Type locality: Figured specimens: Diagnosis: Distribution: Semillia pauper sp. nov. From Latin, pauper, poor; referring to the smooth outer surface of the valves. Commonwealth Palaeontological Collections, Bureau of Mineral Resources, Canberra, Australia (CPC) no. 23253; carapace. 500 m S of the telegraph line, Rogers Ridge, Duchess Region, Queensland, Australia; approximately lat. 21° 45.4' S, long. 139° 58.8' E. Monastry Creek Phosphorite Member, Beetle Creek Formation; late Templetonian, middle Cambrian; with Xystridura. Commonwealth Palaeontological Collections, Bureau of Mineral Resources, Canberra, Australia (CPC) nos. 23253 (holotype, car.: PI. 19, 14, figs. 1-4), 23252 (car.: PI. 19, 16, figs. 1-3), 23251 (LV: PI. 19, 16, fig. 4). Both from the type locality. Up to 3.2 mm long. In other respects as for the genus; Semillia is currently monotypic. Known only from type locality. Explanation of Plate 19, 16 Figs. 1-3, car. (paratype, CPC 23252, 2.3 mm long): fig. 1, ext. It. lat.; fig. 2, ext. dors.; fig. 3, ext. vent. Fig. 4, LV, int. lat. (CPC 2325, 1 .9 mm long). Scale A (500 pm, x23), figs. 1-3; scale B (500 pm, x27), fig. 4. ) Stereo-Atlas of Ostraeod Shells 19 (5) 17-20 (1992) Cuneoceratina exornata (1 of 4) 595.337.14 (116.333.3) (489: 161.014.55): 552.55 ON CUNEOCERATINA EXORNATA (HERRIG) by Ekkehard Herrig (University of Greifswald, Germany) Cuneoceratina exornata (Herrig, 1966) 1966 Monoceratina (sgen. nov. ? 1) exornata sp. nov. E. Herrig, Palaont. Abh. Bert., A, 2, 4, 909, pi. 40, figs. 1, 2, text-fig. 1 18d. Holotype: Fachrichtung Geowissenschaften, Ernst-Moritz-Arndt-Universitat, Greifswald, Germany, no. GPIG Os 87. Type locality: Uppermost section of the chalk complex no. 14, sample no. 3/103, beach at Jasmund, Isle of Riigen, Baltic Sea; lat. 54°33'N, long. 13°40'E. Upper part of lower Maastrichtian, upper Cretaceous. Figured specimens: Fachrichtung Geowissenschaften, University of Greifswald, Germany (GPIG), nos. 5291/1 (LV: PI. 19, 18, fig. 1), 5291/2 (RV: PI. 19, 18, fig. 2; PI. 19, 20, fig. 3), 16591/1 (RV: PI. 19, 20, fig. 2) and 16591/2 (anteroventrally incomplete RV: PI. 19, 20, fig. 1). Specimens 5291/1, and 5291/2 are from flint erratic boulder no. La 6/11/89. Specimens 16591/1 and 16591/2 are from flint erratic boulder “Wieck grau”. Both erratic boulders are from “Adler Grund’’, off SW part of Isle of Bornholm (Baltic Sea), Denmark; upper Maastrichtian, Cretaceous. Explanation of Plate 19, 18 Fig. 1, LV ext. lat. (5291/1, 1.12 mm long, including spines); fig. 2, RV ext. lat. (5291/2, 1.02 mm long, most spines are broken). Scale A (100 /um, x70), fig. 1; scale B (100 /um, x83), fig. 2. Stereo-Atlas of Ostraeod Shells 19, 19 Cuneoceratina exornata (3 of 4) Diagnosis: Remarks: Distribution: Cuneoceratina species with valves more than 1 mm long; rhomboid outline, reticulate shell surface, long lateral spine posteroventrally covered by tiny denticles. Marginal ridges with lines of spines: anteriorly, ventrally and one line on dorsal ridge. On shell reticulation, spines are scarce and scattered; dense below deepened muscle scar field where (ventrocentrally) they form a line. The newly obtained knowledge of well preserved shells and sculptural details [recovered by dis- aggregation of siliceous chalk (“flint stone”) by treatment with hydrofluoric acid] requires the redescription of a species first described in 1966. The species was originally established on the basis of incomplete valves and ill-preserved elements of fine sculpture (broken posteroventral and marginal spines and surface reticulation). The distally expanding, club-like character of many of the spines is typical for the species. Upper Cretaceous. The white chalk of the Isle of Riigen and boreholes from the Isle of Usedom (Baltic Sea); lower Maastrichtian. Also from flint erratic boulders from northern Germany and the floor of the Baltic Sea; upper Maastrichtian. Explanation of Plate 19, 20 Fig. 1, RV (16591/2, 0.96 mm long): int. lat. (anterovent. incomplete); fig. 2, RV (16591/1, 1.04 mm long): ext. dors.; fig. 3, RV (5291/2): ext. lat., detail. Scale A (100 gm, x83), figs. 1, 2; scale B (100 /rm, x240), fig. 3. Stereo-Atlas of Ostracod Shells 19, 20 Stereo-Atlas of Ostracod Shells 19, 18 Cuneoceratina exornata (2 of 4) Cuneoceratina exornata (4 of 4) Stereo-Atlas of Ostracod Shells 19 (6) 21-24 (1992) Scaldianella simplex (1 of 4) 595.337.2 (113.331) (420 : 162.003.52): 551.351 +552.54 ON SCALDIANELLA SIMPLEX (KRAUSE) by Lee E. Petersen & Robert F. Lundin (Anardarko Petroleum Corporation, Houston, Texas & Arizona State University, Tempe, U.S.A.) Genus SCALDIANELLA Gailite, 1967 Type-species (by original designation): Thtipsura simplex Krause, 1891 Diagnosis: Unisulcate, ? bisulcate or trisulcate Cavellinidae (Cavellininae) with strong dorsal and ventral overreach of left valve by right valve. Anterior straguloid process weak. Limen in posteroventral part of each female valve broadens ventrally. Remarks: Gailite (in: Gailite, L.K., Rybnikova, M.V. & Ul’st, R.Zh., Stratigraphy, fauna, and conditions of formation of the Silurian rocks of the centra! Baltic region, [Russian], 151, 152, Izdat. “Zinatne”, Riga, 1967), Sar \ (in: Kaljo, D. (ed.), Facies and fauna of the Baltic Silurian, [Russian], 269-273, Acad. Sci. Est. SSR, Tallinn, 1977) and other authors have included unisulcate as well as trisulcate species in Scaldianella. Additionally, Sarv (1977, op. cit.) and Zbikowska (Bull. Acad. pol. Sci. Ser. Sci. Terre, 21(2), 144, 145, 1973; Acta geol. pol., 23(4), 633, 1973) included a species, S. bisulcata Zbikowska, with two dorsoventrally oriented depressions on each valve, one of which is S2 and the other of which may or may not be a true sulcus. If it is a true sulcus, under present taxonomy the genus contains uni-, bi- and trisulcate species. In this case sulcation is used as a species character, whereas, in a related group, the kloedenellids, the same character has been considered to be of generic significance. We suggest that this practice should be reconsidered. Under its presently accepted concept, the genus is known from S. simplex, S. personata and S. bisulcata, all from Poland, the eastern Baltic region and/or Podolia (Ukraine). The discovery of the material described here extends the known geographic occurrence of the genus to Great Britain. Ulrich and Bassler’s (Maryland Geol. Surv., Lower Devonian Volume, 538, 1913) report of S. simplex (reported as Octonaria simplex ) in the Keyser Formation of Maryland needs to be checked. Their illustrations indicate the species present there is not a Scaldianella. Explanation of Plate 19, 22 Figs. 1, 3, 9 car. (ASU X-197, 846 t/m long): fig. 1, ext. It. lat.; fig. 3, ext. vent. Figs. 2, 4, c r car. (ASU X-198, 827 pm long): fig. 2, ext. dors.; fig. 4, ext. It. lat. Fig. 5, o* RV, int. lat. (ASU X-199, 695 pm long). Scale A (200 pm; x60), figs. 1, 3; scale B (200 pm\ x62), figs. 2, 4; scale C (200 pm\ x73), fig. 5. Stereo-Atlas of Ostracod Shells 19, 23 Scaldianella simplex (1 of 4) Scaldianella simplex (Krause, 1891) 1891 Thtipsura simplex sp. nov. A. Krause, Z. dt. geol. Oes., 43, 508, pi. 32, fig. 16. 1932 Thlipsurella? simplex (Krause); F.M. Swartz, J. Paleont., 10, 45. 1967 Scaldianella simplex (Krause); L.K. Gailite, in: Gailite, L.K., Rybnikova, M.V. & Ul’st, R.Zh., Stratigraphy, fauna, and conditions of formation of the Silurian rocks of the central Baltic region, [Russian], 152, pi. 12, fig. 5, Izdat. “Zinatne”, Riga. 1968 Krausellina simplex (Krause); V.S. Krandijevsky, in: Krandijevsky, V.S., Ishchenko, T.A. & Kiryanov, V.V., Paleontology and stratigraphy of the lower Paleozoic of Volyn-Podolia, [Russian], 73, pi. 11, fig. 24, Ukr. Akad. Nauk. 1973 Scaldianella simplex (Krause); B. Zbikowska, Acta geol. pol., 23(4), 633, pi. 8, fig. 2a, b. 1977 Scaldianella simplex (Krause); L. Sarv, in: Kaljo, D., Facies and fauna of the Baltic Silurian, [Russian], 270, pi. 4, figs. 1-11, Acad. Sci. Estonian S.S.R., Tallinn. 1986 Scaldianella simplex (Krause); R.E.L. Schallreuter, Mitt, geol.-palaeont. Inst. Univ. Hamburg, 61, 213, pi. 4, fig. 5. 1991 Scaldianella simplex (Krause); R.F. Lundin, L.E. Petersen & D.J. Siveter, /. Micropalaeontol. , 9 (pt. 2 for 1990), 180, pi. 2, fig. 4. 1991 Scaldianella simplex (Krause); W. Hansch, Arch. Geschiebe, 1(2), 98, pi. 5, fig. 1. Holotype: Type locality: Figured specimens: Diagnosis: Remarks: Distribution: Acknowledgements: Palaeozoological Section, Berlin Museum of Natural History (M.B.O.), Berlin, Germany; no. M.B.O. 138; left valve (see Hansch 1991, op. cit.). The type specimen came from an erratic boulder (Beyrichienkalk no. 97 of Krause 1891, op. cit.), at Miiggelheim in northern Germany. Department of Geology, Arizona State University, (ASU), nos. X-140 (9 car.: PL 19, 24, figs. 1, 2), X-197 (9 car.: PI. 19, 22, figs. 1, 3), X-198 (a car.: PI. 19, 22, figs. 2, 4), X-199 (o- RV: PI. 19, 22, fig. 5), X-200 (9 car.: PI. 19, 24, figs. 3, 4). ASU X-140, ASU X-197, ASU X-198 and ASU X-200 are from Wren’s Nest, Dudley, West Midlands, England, lat. 2.05' W, long. 52.30' N. ASU X-199 is from Lincoln Hill about 250 m N of the River Severn at Ironbridge, Shropshire; lat. 2.30' W, long. 52.38' N. All figured specimens are from the Much Wenlock Limestone Formation; Homerian Stage, Wenlock Series, Silurian. Unisulcate Scaldianella in which females have a poorly developed limen. Domatial dimorphism indistinct, but females somewhat more swollen posteriorly than males. Males generally with greater length/height ratio than females. The specimens described here compare favourably with specimens of the species from Estonia provided by L. Sarv, although, normally, the Estonian specimens, as well as the holotype, have a more distinct S2 than the British specimens. With the discovery of the material reported here, the species is now known from Silurian erratics of northern Germany, late Wenlock and early Ludlow strata of the English West Midlands and the Welsh Borderland, and late Ludlow and early Pridoli strata of the eastern Baltic area. We gratefully acknowledge support of NATO and the National Science Foundation (Grant No. EAR-8200816). Explanation of Plate 19, 24 Figs. 1, 2, 9 car. (ASU X-140, 771 pm long): fig. 1, ext. It. lat.; fig. 2, ext. dors. Figs. 3, 4, 9 car. (ASU X-200, 152pm long): fig. 3, ext. rt. lat.; fig. 4, ext. It. lat. Scale A (200 pm\ x66), figs. 1, 2; scale B (200 pm; x68), figs. 3, 4. Scaldianella simplex (4 of 4) Stereo-Atlas of Ostracod Shells 19, 22 Scaldianella simplex (2 of 4) Stereo-Atlas of Ostracod Shells 19, 24 Stereo-Atlas of Ostracod Shells 19 (7) 25-28 (1992) Glyptopleuroides insculptus (1 of 4) 595.336.17 (?) (1 13.51) (761 : 162.088.34): 551.351 +552.52 ON GLYPTOPLEUROIDES INSCULPTUS CRONEIS & GALE by Christopher P. Dewey & Janet E. Coker (Mississippi State University, Mississippi & Auburn University, Alabama, U.S.A.) Genus GLYPTOPLEUROIDES Croneis & Gale, 1939 Type-species (by original designation): Glyptopleuroides insculptus Croneis & Gale, 1939 1939 Glyptopleuroides gen. nov. C. Croneis & A.S. Gale, J. Scient. Labs Denison Univ ., 33, 283, pi. 6, fig. 32. Diagnosis: Small, subrhomboidal Glyptopleuroides ; lateral surface has by marginal rim and elsewhere, broad, flat ridges separated by grooves. Ridges may anastomose. Hinge merodont? Free margin with transverse elements on inner flange; details of calcified inner lamella uncertain. G/ytopleuroides insculptus Cronies & Gale, 1939 1939 Glyptopleuroides insculptus sp. nov. C. Croneis & A.S. Gale, J. scient. Labs Denison Univ., 33, 283-4, pi. 6, fig. 32. 1941 Glyptopleuroides insculptus Croneis & Gale; C.L. Cooper, Rep. Invest. III. St. geol. Surv., 77, 9, 17, pi. 8, figs. 28, 29. Holotype: Field Museum of Natural History, Chicago, U.S.A. , no. UC 44435; adult carapace. Type locality: Locality no. Gl, South line, Sec. 25, T11S R9E, Shawneetown Quadrangle, Illinois, U.S.A.; lat. 37°31'31"N, long. 88°09'31"W. Golconda Formation, Chesterian, Mississippian, Carboniferous. Figured specimens: Field Museum of Natural History, U.S.A., no. UC 44435, (holotype, adult car: PI. 19, 26, fig. 1). Dunn-Seiler Museum of Geology, Mississippi State University, U.S.A., nos. 3341-5a (adult car: PI. 19, 28, fig. 1), 3341-5b (juv. car: PI. 19, 26, figs. 2-4), 3341-5c (juv. RV: PI. 19, 28, figs. 2-5). No. UC 44435 from type locality, Illinois, U.S.A. Nos. 3341-5a, 3341-5b from light brown fossiliferous mudstone, N side of county highway 56, east of Mountain Star, Sec. 7, T6S R10W, Franklin County, Alabama, U.S.A.; lat. 34°32'50"N, long. 87°37'49"W. No. 3341-5c from light brown fossiliferous mudstone, county Explanation of Plate 19, 26 Fig. 1 , adult car., RV ext. lat. (UC 44435, 0.70 mm long). Figs 2-4, juv. car. (3341-5b, 0.62 mm long); fig. 2, LV ext. lat.; fig. 3, RV ext. lat.; fig. 4, ext. dors. Scale A (250 pm; x85), fig. 1; scale B (200 //m; x86), figs. 2-4. Stereo-Atlas of Ostracod Shells 19, 27 Glyptopleuroides insculptus (3 of 4) Diagnosis: Remarks: Distribution: A cknowledgement: highway 37, Sec. 31, T5S R10W, Colbert County, Alabama, U.S.A.; lat. 34° 34' 12"N, long. 87°37'28"W. Bangor Limestone Formation, Chesterian, Mississippian. Small, subrhomboidal; dorsal and ventral margins straight, ends evenly rounded, slight anteroventral swing, anterior broadly rounded with maximum curvature anteroventrally. Dorsal aspect suboblong, maximum width posterior to midlength; hinge slightly incised. Surface has broad, flat, variably anastomosing ridges separated by grooves. Marginal rim extends from cardinal angles around free margin. Vertical ridge extends from posterodorsal corner just anterior of cardinal angle to ventral marginal rim. Three, anastomosing and posteriorly furcated, obliquely trending, lateral ridges fused in anteroventral quadrant posterior to marginal rim. Ridges confluent with posterior vertical ridge. Fourth, less distinct ridge, ventral to other three, fused with marginal rim anteroventrally. Marginal rim and all major ridges marked by vein-like ridges/reticulation. Grooves irregular, smooth. Hinge merodont (?), crenulate cardinal teeth in right valve. Free margin with transverse elements on inner surface. The holotype of G. insculptus Croneis & Gale, 1939 is an adult carapace but no paratypes were designated; thus, hitherto, the internal morphology of the genus was unknown. The genus was questionably referred to the Youngiellacea (Sohn, in: Moore, R.C. (ed.), Treatise Invert. Paleont., Pt. Q, Arthropoda 3, 178, 1961), but our material from the Black Warrior Basin shows that G. insculptus differs from other youngiellaceans in two important respects. Firstly, G. insculptus has posterior crenulate hinge teeth in the right valve but no specimens have been found with the taxodont hinge typical of the youngiellaceans. If the hinge could be shown to be merodont, then together with the valve outline, this fact could be used to suggest a quasillitid affinity for the genus. Secondly, the inner surface of the free margin of G. insculptus possesses ridge-like elements, perpendicular to the valve margin. This feature is unlike the calcified inner lamella described for Youngiella (see Gramm, Vnutrennie stuktur rakovin Paleozoiski ostrakod, Akademia Nauk S.S.S.R., Leningrad, 4, 25, pi. 10, figs. 11, 13, pi. 31, figs. 4-16, 1984; Dewey & Coker, Stereo-Atlas Ostracod Shells, 18, 29-32, 1991). It is not likely, therefore, that Glyptopleuroides is a youngiellacean, although its true taxonomic position is still enigmatic. Chesterian Series, Mississippian, Lower Carboniferous, U.S.A. We acknowledge the financial support given by the Donors of the Petroleum Research Fund administered by the American Chemical Society. Explanation of Plate 19, 28 Fig. 1, adult car., LV ext. lat. (3341-5a, 0.77 mm long). Figs. 2-5, juv. RV (3341-5c, 0.65 mm long): fig. 2, RV ext. lat.; fig. 3, RV int. lat.; fig. 4, RV int. anterovent. margin; fig. 5, int. post, hinge. Scale A (200^m; x78), fig. 1; scale B (200pm; x86), figs. 2, 3; scale C (100/nn; xl64), figs. 4, 5. Stereo-Atlas of Ostracod Shells 19, 26 Glyptopleuroides insculptus (2 of 4) Slereo-Atlas of Ostracod Shells 19 (8) 29-32 (1992) Glezeria belgica (1 of 4) 595.336 (1 13.45) (493 : 161.004.50): 551.351 + 552.52 ON GLEZERIA BELGICA (MATERN) by Gerhard Becker & Michel Coen (University of Frankfurt, Germany & University of Louvain-la-Neuve, Belgium) Glezeria belgica (Matern, 1929) 1929 Bollia belgica sp. nov. H. Matern, Abh. preuss. geol. Landesanst. , N.F., 118, 30, 31, pi. 2, figs. 22 a-c. 1974 Glezeria belgica (Matern); G. Becker, M.J.M. Bless, M. Streel & J. Thorez, Meded. Rijks geol. Dienst., N.S., 25(2), pi. 2, figs. 11, 13, ? 12. 1977 Glezeria belgica (Matern); M. Coen, Annls Soc. geol. Belg., 100, 27. 1987 Glezeria ? belgica (Matern); J.-G. Casier, Bull. Soc. beige Geol., 96, 26. 1988 Balantoides sp.; J.-G. Casier, Bull. Inst. r. Sci. nat. Belg. (Sciences de la Terre), 58, 81, pi. 2, fig. 17. Holotype: Type locality: Figured specimen: Institute royal des Sciences naturelles de Belgique, Bruxelles, Belgium, no. IRBala; an adult LV. Les Abannets, Nismes village, about 4 km E of Frasnes village, S border of the Dinant basin, Belgium; lat. 50°04'N, long. 4°34'E. Green-greyish to brownish fossiliferous shales, Upper asymmetricus conodont zone, middle Frasnian (F2e), Upper Devonian. Forschungs-Institut Senckenberg, Frankfurt am Main (SMF), Germany, nos. SMF Xe 15152 (adult cr car.: PI. 19, 30, fig. 1; PI. 19, 32, fig. 2), SMF Xe 15153 (adult o* car.: PI. 19, 30, fig. 2; PI. 19, 32, fig. 1), SMF Xe 15154 (adult 9 car.: PI. 19, 30, fig. 3), SMF Xe 15155 (adult 9 car.: PI. 19, 32, figs. 3, 4), SMF Xe 15156 (adult 9 car.: PI. 19, 32, fig. 5). Explanation of Plate 19, 30 Fig. 1, adult cr car., rt. lat. (SMF Xe 15152, 875,«m long). Fig. 2, adult cr car., ant. (SMF Xe 15153, 910pm long). Fig. 3, adult 9 car., rt. lat. (SMF Xe 15154, 845 pm long). Scale (100 pm\ x85), figs. 1-3. Stereo-Atlas of Ostracod Shells 19, 31 Glezeria belgica (3 of 4) Diagnosis: Remarks: Distribution: All the figured specimens are from the type level at Boussu-en-Fagne, 7 km W from the type locality; lat. 50°05'N, long. 4°28'E. Glezeria species with comparatively short median sulcus and broad ventral lobe. Hamal structure in tecnomorphs is a short but strongly developed anterodorsally located hook, in heteromorphs it is a low but distinct, anteriorly located ridge. Glezeria belgica was originally placed in the genus Bollia Jones & Holl, 1886. In connection with a revision of the ostracod species established by Matern (1929) (see G. Becker, Bull. Inst. r. Sci. Beige, 47, 34, 1971) the species was then transferred by Becker et al. (1974 op. cit.) to the taxon Glezeria Shishkinskaya, 1968, a genus originally proposed for bilobate “drepanellids”. This genus, however, belongs (as indicated, herein, by the morphology of Glezeria belgica) to the Superfamily Nodellacea Becker, 1968, because of the occurrence of the distinct hamal type of dimorphism. Glezeria belgica is considered to have been a benthic species. Belgium; middle to upper Frasnian, probably lower Famennian, Upper Devonian. Explanation of Plate 19, 32 Fig. 1, adult cr car., vent. (SMF Xe 15153, 910pm long). Fig. 2, adult cr car., dors. (SMF Xe 15152, 875 pm long). Figs. 3, 4, adult 9 car. (SMF Xe 15155, 825 pm long): fig. 3, vent.; fig. 4, ant. Fig. 5, adult 9 car., post. (SMF Xe 15156, 825 pm long). Scale A (100 /rm; x85), figs. 1, 3; scale B (100 /rm; x82), fig. 2; scale C (100 ^m; x80), figs. 4, 5. Stereo-Atlas of Ostracod Shells 19, 30 G/ezeria belgica (2 of 4) Glezeria belgica (4 of 4) Stereo-Atlas of Ostracod Shells 19, 32 : Stereo-Atlas of Ostracod Shells 19 (9) 33-36 (1992) Kanyginia hartmanni (1 of 4) 595.33.13 (113.312) (57: 161.062.64): 551.351 ON KANYGINIA HARTMANNI SCHALLREUTER & KANYGIN sp. nov. by Roger E.L. Schallreuter & Aleksandr V. Kanygin (University of Hamburg, Germany & Russian Academy of Sciences, Siberian Branch, Novosibirsk) Kanyginia hartmanni sp. nov. Deviation of name: Holotype: Type locality: Figured specimens: In honour of Professor Gerd Hartmann, University of Hamburg. Institute of Geology, Siberian Branch of the Russian Academy of Sciences (RAN), Novosibirsk (IGN), no. 1054/7; female left valve. At depth 76.9 m in borehole 4-6, Dyukunak, Morkoka river area, Siberia; approximately lat. 64°45'N, long. 62°30'E. Stan Formation, Chertovskian, middle Ordovician. Institute of Geology, Novosibirsk, (IGN) nos. 1054/7 (holotype, 9 LV: PI. 19, 36, fig. 1), 1054/8 (RV: PI. 19, 34, fig. 2), 1054/9 (RV: PI. 19, 34, fig. 1), and 1054/10 (RV: PI. 19, 36, fig. 2). All specimens are from the type locality. Of the figured specimens only the sex of the holotype is certain. Explanation of Plate 19, 34 Fig. 1, RV ext. lat. (IGN 1954/9, 0.90mm long); fig. 2, RV ext. lat. (IGN 1054/8, 0.71 mm long). Scale A (100 /ym; x 1 10), fig. 1; scale B (100 /ym; x 135), fig. 2. Stereo-Atlas of Ostracod Shells 19, 35 Kanyginia hartmanni (3 of 4) Diagnosis: Remarks: Distribution: Species of Kanyginia with length up to 0.90 mm. Sulcus (S2) relatively shallow. A swarm of ridges also posterior of sulcus, incorporating more than half of posterior field of the valve. The new species is very similar to the slightly older type-species of Kanyginia, Oecematobolbina armilata Kanygin, 1971 ( Trudy Inst. Geol. Geofiz. sib. Otd., 128, 58), from the lower Labystakh Formation of Sette-Daban, Siberia. The latter species differs in having fewer ridges in its ornament and in that the ridges only occur in the ventral and anterior parts of the valve (see Kanygin, op. cit., pi. 5, figs. 1-4). Furthermore, the sulcus is deeper in K. armilata than in K. hartmanni. Kanyginia Schallreuter & Kruta (Neues Jb. Geol. Palaont. Mh., 1980(8), 506) was originally established as a subgenus of Hippula ( = Oecematobolbina). As shown by the new species herein, there are no rhombiform septa between the ridges in Kanyginia. Kanyginia is, therefore, no longer considered to be a subgenus of Hippula. However, it is still considered to be a member of the Tribe Hippulini Schallreuter ( Palaeontographica , (A), 108(4/6), 144, 1983). Known only from the type locality, Stan Formation, middle Ordovician of the Siberian platform. Explanation of Plate 19, 36 Fig. 1, 9 LV ext. lat. (holotype, IGN 1054/7, 0.84 mm long); fig. 2, RV ext. lat. (IGN 1054/10, 0.79mm long). Scale A (100 /ym; x 1 10), fig. 1; scale B (100 /ym; x 120), fig. 2. Stereo-Atlas of Ostracod Shells 19, 34 Kanyginia hartmanni (2 of 4) Kanyginia hartmanni (4 of 4) Stereo-Atlas of Ostracod Shells 19, 36 Stereo-Atlas of Ostracod Shells 19 (10) 37-40 (1992) Fidelitella ( Sibiritella ) rara (1 of 4) 595.33.13 (113.312) (57 : 161 .062.64): 551.551 ON FIDELITELLA (SIBIRITELLA) RARA (IVANOVA) by Roger E.L. Schallreuter & Aleksandr V. Kanygin (University of Hamburg, Germany & Russian Academy of Sciences, Siberian Branch, Novosibirsk) Genus FIDELITELLA V. Ivanova, 1960 Type-species (by original designation): Tritobella unica V. Ivanova, 1955 Soanellid with asymmetrical carapace. Right valve quadrilobate; left valve tri- or quadrilobate, lobes weaker than in right valve. No adventral sculptures. Sexual dimorphism unknown. Subgenus FIDELITELLA < SIBIRITELLA ) Kanygin, 1967 Type-species (by original designation): Tetradella rara Ivanova, 1955 Both valves quadrilobate. SI in both valves short; lobes in left valve flatter than in right valve. In the asymmetry of its valve morphology (and in the fact that its sexual dimorphism is unknown) T. rara Ivanova, 1955 compares with Fidelitella Ivanova, 1960 (in: I.E. Zanina et al., Osnovy paleontologii, 8, 305). In the type-species of the latter genus, Trilobella unica V.A. Ivanova (in: E.A. Ivanova et al., Trudy PIN, 56, 178, 1955), the right valve has a long L2 and a deep SI which is missing in the left valve. F. (S.) rara exhibits, in both valves, a short, discrete L2 and a corresponding short SI. F. (F.) simplex (Ivanova, 1955) has a similar short SI in the left valve but has a long SI in the right valve. Thus, in this respect F. simplex forms, morphologically, a transition between F. unica and F. rara. Whereas in both F. (F.) unica and F. (F.) simplex SI in the larger left valve is either missing or is shorter than that of the right valve, in Sibiritella SI and L2 are symmetrical between valves. The asymmetry of the valves in F. (S.) is expressed mainly by the strength of the development of the lobes. In this respect Sibiritella is still, therefore, considered as a discrete subgenus. Fidelitella (Sibiritella) rara (Ivanova, 1955) 1955 Tetradella rara Ivanova; O.I. Nikiforova, Polevoj atlas ordovikskoj i silurijskoj fauny Sibirskoj platformy , 16, BSEGE1, Moscow. 1955 Tetradella rara sp. nov. V.A. Ivanova, Ibid., 113, 182, pi. 20, fig. 5. 1960 Tetradella rara V. Ivanova; V.A. Ivanova, Mater. Osnov. Paleont., 3, 80. Explanation of Plate 19, 38 Fig. 1, LV ext. lat. (GP1MH 3237, 2.12 mm long). Fig. 2, RV ext. lat. (GPIMH 3238, 2.20 mm long). Scale A (250 pm; x38), fig. 1; scale B (250/tm; x44), fig. 2. Diagnosis: Diagnosis: Remarks: Stereo-Atlas of Ostracod Shells 19, 39 Fidelitella (Sibiritella) rara (3 of 4) 1967 Sibiritella rara (V. Ivanova); V.A. Kanygin, Ostrakody ordovika gornoj sistemy Sherskogo, 87, 88, 89, 90, 92, 94, 125, 135, 138, 151, pi. 16, figs. 1-5, table 2, 3, 6, 10, Nauka, Moscow. 1971 Sibiritella rara (V. Ivanova); V.A. Kanygin, Trudy Inst. Geol. Geofiz. sib. Otd., (IGiG), 128, 81. 1972 Sibiritella rara (V. Ivanova); V.A. Ivanova, Katalog originalov, Ostrakody, 81, 86, Acad. Sci., Moscow. 1973 Valentella rara (V. Ivanova); A.l. Neckaja, Trudy VNIGRI, 324, 36, 72. 1974 Sibiritella rara (V. Ivanova); G.R. Kolosnitsyna in: L.V. Ogienko et al., Biostratigrafija kembrijskich i ordovikskich otlozhenij juga Sibirskoj platformy, 48, 97, 198, pi. 33, figs. 8, 9, Nedra, Moscow. 1974 Sibiritella rara (V. Ivanova); A.V. Kanygin, Trudy IGiG , 84, 92, 97. 1975 Sibiritella rara (V. Ivanova); G.R. Kolosnitsyna in: Yu. I. Tesakov, Ibid.. 200, 21, 78, 82, 187, 207, 214, 215, 218, 236, fig. 11, table 4, 5. 1979 Sibiritella rara (V . Ivanova); V.A. Ivanova, Trudy PIN, 172, 165, 166, 167, 191, pi. 14, figs. 10, 11. 1980 Sibiritella rara (V. Ivanova); A.V. Kanygin et at, Geologiya Geofiz., 1980(6), 17. 1982 Sibiritella rara (V. Ivanova); Ju.I. Tesakov et al., Trudy IGiG, 506, 47, 48, figs. 5, 8 (logs). 1984 Sibiritella rara (V. Ivanova); A.G. Jadrenkina et al.. Ibid.. 584, fig. p. 18 (log). 1984 Sibiritella rara (V. Ivanova); A.V. Kanygin et al.. Ibid., 590, 12. 1984 Sibiritella rara (V. Ivanova); A.V. Kanygin, Ibid. , 590, 91, 222, pi. 22, figs. 2-3, 5, 8-10 (non fig. 6). 1984 Sibiritella rara (V. Ivanova); A.V. Kanygin et al.. Ibid., 595, 80. 1985 Sibiritella rara (V. Ivanova); A.V. Kanygin, Ibid., 615, 7. 1987 Sibiritella rara (V. Ivanova); Ju. Ja. Schabanov et al., Niznij paleozoja jugo-zapadnogo cklona Anabarskoj anteklizy, 39, Nauka, Novosibirsk. 1988 Sibiritella rara (V. Ivanova); A.V. Kanygin et al., Publ. Int. Un. Geol. Sci., 26, 6, pi. A. 1988 Sibiritella rara (V. Ivanova); A.V. Kanygin in: M.M. Oradovskaya, Ibid., 26, 104, pi. D. 1989 Sibiritella rara (V. Ivanova); V.A. Kanygin et al., Trudy IGiG., 751, 18, 19, 20, 21, 28, 35, 36, 152, figs. 3, 7 (logs), table 2. 1990 Sibiritella rara (V. Ivanova); V.A. Ivanova in: Abushik et al., Prakt. rukov. mikrof. S.S.S.R., 4, 63, 233, pi. 8, fig. 9. Holotype: Type locality: Figured specimens: Diagnosis: Remarks: Distribution: Palaeontological Institute, Russian Academy of Sciences, Moscow (PIN), no. 1597/4; left valve. River Nyuya, near Mukhtuya, Siberian platform; approximately lat. 60°31'N, long. 116°23'E. Lower Krivolukian, Volginian, middle Ordovician. Geologisch-Palaontologisches Institut and Museum, University of Hamburg, Germany (GPIMH) nos. 3237 (LV: PI. 19, 38, fig. 1). 3238 (RV: PI. 19, 38, fig. 2), 3239 (RV: PI. 19, 40, fig. 1), and 3240 (LV: PI. 19, 40, fig. 2). All from Dyukunak: boring 1-4, depth 135.1 m; Morkoka River, Siberian platform; approximately lat. 64°45'N, long. 62°30'E. Krivaya Luka Formation, Volginian, middle Ordovician. Species of F. (Siberitella) up to 3 mm long. Outline of right valve semi-ovoid. Lobes connected ventrally; LI, L3 and L4 gradually become more elevated in dorsal direction, dorsal ends being bulb-like. Lobes lack pores or furrows. F. (S.) furcata Kanygin, 1967 (op. cit., 90) differs from F. (S.) rara mainly by the more distinct asymmetry of its valves, the more trapezoid outline of its right valve and in lacking a ventral connection to its lobes which furthermore, are more equal in height and show a development of pores and furrows (Kanygin, 1967, op. cit., 92). Volginian of Siberian platform: Rivers Nyuya, Lena, Poloviny, Moyero, Morkoka, Kulyumbe. Lachugian of NE Siberia. Explanation of Plate 19, 40 Fig. 1, RV ext. lat. (GPIMH 3239, 2.11 mm long); fig. 2, LV ext. lat. (GPIMH 3240, 2.17 mm long). Scale A (250 pm; x43), fig. 1; scale B (250 pm; x37), fig. 2. Stereo*Atlas of Ostracod Shells 19, 38 Fidelitella ( Sibiritella ) rara (2 of 4) Fidelitella ( Sibiritella ) rara (4 of 4) Stereo-Atlas of Ostracod Shells 19, 40 Stereo-Atlas of Ostracod Shells 19 (11) 41-48 (1992) Pseudocandona ceratina (1 of 8) 595.337.12 (1 19.9) (57: 161.109.55): 551.312 ON PSEUDOCANDONA CERATINA MAZEPOVA by Koen Martens, Irina Noskova & Galina Mazepova (Royal Belgian Institute of Natural Sciences, Brussels & Limnological Institute, Siberian Branch of the Russian Academy of Sciences, Irkutsk) Pseudocandona ceratina Mazepova, 1982 1982 Pseudocandona ceratina sp. nov., G. Mazepova, Novoye o Faune Baikala, 120, fig. 7, “Nauka” (Sib. Otdel. Akad. Nauk S.S.S.R.), Novosibirsk. 1990 Pseudocandona ceratina Mazepova; G. Mazepova, Rakuschkovye ratschki (Ostracoda) Baikala , 197-200, figs. 77, 78, Ibid. Holotype: Type locality: Figured specimens: Diagnosis: (originally designated as “type specimen’’): a 9, with the following measurements: LV: L = 888/um, H = 518//m; RV: L = 874//m, H = 483/um. Limnological Institute, Siberian Branch of the Russian Academy of Sciences, Irkutsk; no catalogue number. Lake Baikal, northern basin, Tompuda (approx, lat. 55°08'N, long. 109°45'E), depth 10 m on sand. Royal Belgian Institute of Natural Sciences, Brussels, Ostracod Collection, nos. OC1599 (o’: PI. 19, 48, fig. 2), OC1600 (o-: PI. 19, 46, fig. 2), OC1601 (O’: PI. 19, 42, fig. 3; 19, 44, fig. 3; text-figs. 2a-f; 3a, d, f), OC1602 (O’: PI. 19, 46, fig. 3; 19, 48 fig. 3), OC1603 (9: PL 19, 44, fig. 2), OC1604 (9: PI. 19, 42, fig. 2), OC1605 (9: PI- 19, 42, fig. 1; 19, 44, fig. 1; text-figs. 3b, c, e, g, h), OC1606 (9: PI- 19, 46, fig. 1; 19, 48, fig. 1). All collected from the vicinity of the type locality. Subrectangular, strongly pitted valves, with straight dorsal margin, broadly rounded anterior margin, and largely sinuous ventral margin, the latter showing a striking sexual dimorphism, with a large, Explanation of Plate 19, 42 Fig. 1, 9 LV, ext. lat. (OC1605, 931 long); fig. 2, 9 car., vent. (OC1604, 897 pm long); fig. 3, cr LV, ext. lat. (OC1601, 879/um long). Scale A (200 ^/m; x75), figs. 1-3. Stereo-Atlas of Ostracod Shells 19, 43 Pseudocandona ceratina (3 of 8) asymmetrically inserted tooth on both valves in males, absent in females. LV overlapping RV ventrally and anterodorsally. Dorsal margin passing into anterior margin with a striking indention in both sexes. Caudal margin forming a nearly rectangular corner with the dorsal margin in females; caudal margin bluntly produced towards the ventral side in males. Anterior inner lamella moderately wide in both valves; RV with a submarginal, weakly developed inner list. Males with four pairs of seminal tubes. Antennula set with (non-flagellated) claws. Antenna without male bristles, but with elongated subterminal segment (length at least 3 times basal width) weakly divided; sexual dimorphism in apical chaetotaxy evident: zl and z2 in males full-grown claws. G3 a small claw; in females zl (or z3) missing, G3 a large claw. Hemipenis with lobes “a’’, “h” and “b” simple; post- labyrinthal part of inner spermiductus uncoiled in relaxed condition; bursa copulatrix large. Prehensile palps consisting of one segment, largely asymmetrical: right palp rounded, with two seta-like lateral processes; left palp strongly developed and sickle-shaped, with two stout seta-like lateral processes and one rounded lobe-like outgrowth. Furcal ramus slightly more curved in females. Remarks: Like Pseudocandona gajewskajae Bronstein, 1947 (see K. Martens, I. Noskova & G. Mazepova, Stereo- Atlas Ostracod Shells 19, 49-56, 1992), P. ceratina probably belongs to a phyletic lineage related to, but quite different from true Pseudocandona. New genera cannot be erected, however, without a thorough re-examination of all European and Baikalian representatives of this apparently polyphyletic genus. Distribution: Recent, freshwater: Lake Baikal. Acknowledgements: Both the visit of the senior author to Lake Baikal and the one of the second author to Belgium were financed by the bilateral agreement between the Belgian Government and the Siberian branch of the Russian Academy of Sciences, presently being incorporated in BICER. J. Cillis and C. Behen (Brussels, Belgium) offered technical assistance with the SEM images and with the line drawings respectively. Dr K. Wouters (Brussels) and Dr D. Danielopol (Mondsee) read the manuscript and suggested improvements. Explanation of Plate 19, 44 Fig. 1, 9 RV, ext. lat. (OC1605, 905 long); fig. 2, 9 car., dors. (OC1603, 966//m long); fig. 3, o’ RV, ext. lat. (OC1601, 845 pm long). Scale A (200 //m; x75), figs. 1-3. Pseudocandona ceratina (2 of 8) Stereo-Atlas of Ostracod Shells 19, 42 Stereo-Atlas of Ostracod Shells 19, 44 Pseudocandona ceratina (4 of 8) Stereo-Atlas of Ostracod Shells 19, 45 Pseudocandona ceratina (5 of 8) Text-fig. 1, schematic representation of sexual dimorphism in distal chaetotaxy of terminal antennal segments (right antenna, apical view) in Pseudocandona ceratina Mazepova ( 1 a) and P. gajewskajae Bronstein ( 1 b) (see also Martens et al. , Stereo- A tlas Ostracod Shells, 19, 49-56, 1992). Large circles represent circumferences of segment, small circles are setae and aesthetascs, ovals are claws. For full explanation, see Martens (Bijdr. Dierk., 57, 183-190, 1987). Text-fig. 2a-f, cr appendages (OC1601): a, hemipenis; b, c, prehensile palps; d, Tl; e, Al; f, T2. Scale bar = 78ium. Explanation of Plate 19, 46 Fig. 1, 9LV, int. lat. (OC1606, 948 /rm long); fig. 2, cr car., vent. (OC1600, 845 nm long); fig. 3, O' LV, int. lat. (OC1602, 862 //m long). Scale A (200 ^/m; x75), figs. 1-3. Stereo-Atlas of Ostracod Shells 19, 47 Pseudocandona ceratina (7 of 8) Text-fig. 3, appendages: a, A2, detail of distal chaetotaxy (OC1601); b, 9, Mx2 (OC1605); c, 9, A2 (OC1605); d, O', A2 (OC1601); e, 9, furca (OC1605); f, cr, furca (00601); g, 9, Mxl-palp (OC1605); h, 9, Mxl, respiratory plate (OC1605). Scale bars = 146 //m for 3e, f, h; 78 //m for 3b-d, g; 29 /um for 3a. Explanation of Plate 19, 48 Fig. 1, 9 RV, int. lat. (OC1606, 948 /mr long); fig. 2, cr car., dors. (OC1599, 862 /rm long); fig. 3, cr RV, int. lat. (OC1602, 845 nm long). Scale A (200 /jm; x75), figs. 1-3. Pseudocandona ceratina (6 of 8) Pseudocandona ceratina (8 of 8) Stereo-Atlas of Ostracod Shells 19, 46 Stereo-Atlas of Ostracod Shells 19, 48 \ Stereo-Atlas of Ostracod Shells 19 (12) 49-56 (1992) 595.337.12 (119.9) (57: 161.105.52): 551.312 Pseudocandona gajewskajae (1 of 8) ON PSEUDOCANDONA GAJEWSKAJAE BRONSTEIN by Koen Martens, Irina Noskova & Galina Mazepova (Royal Belgian Institute of Natural Sciences, Brussels & Limnological Institute, Siberian Branch of the Russian Academy of Sciences, Irkutsk) Pseudocandona gajewskajae Bronstein, 1947 1947 Pseudocandona gajewskajae sp. nov. G. Bronstein, Fauna U.S.S.R. 2(1), 202-203, 317-318, fig. 115. 1969 Alatocandona gajewskajae (Bronstein); G. Carbonnel, Docums Lab. Geol. Fac. Sci. Lyon, 32(1), 28. , ... . 1990 Pseudocandona gajewskajae Bronstein; G. Mazepova. Rakuschkovye ratschki (Ostracoda) Baikala, 247-250, fig. 104, Nauka (Sib. Otdel. Akad. Nauk S.S.S.R.), Novosibirsk. Twe specimens • Repository unknown; however, Bronstein’s (op. cit.) original description and illustration are adequate to define the species. Lake Baikal, southern basin, Bol’shie Koty (approx, lat. 52°20'N, long. 105° E), on stone surface, depth approx. 1.0m. Roval Belgian Institute of Natural Sciences (Brussels, Belgium), Ostracod Collection: OC1590 (9: PI. 19, 50, figs. 1, 4; 19, 52, figs 4 5) OC1592 (9: PI. 19, 50, figs. 2, 3), OC1593 (9: PE 19, 52, figs. 1, 2, 3, 6), OC1594 (or; PI. 19, 54, figs. 2, 3; text-figs, le, 2c), OC1596 (ct: PI. 19, 56, fig. 2), OC1597 (c: PI. 19, 54, fig. 1; 19, 56, fig. 1; text-figs, la-d, f-k, 2a, d-h), OC1598 (9: text-fig. 2b). All collected from the general vicinity of the type locality. Medium-sized candonid, with nearly straight dorsal and ventral sides and with asymmetrically rounded anterior and posterior margins. Both sexes with very striking, hollow lateral alae, about Vi-Vi the total length, in dorsal view each as wide as rest of valve. Entire external surface set with a network of strong ridges. LV overlapping RV on all four sides, consequently being larger, and especially higher than RV. LV further with a well developed, submarginal inner list along anterior, ventral and posterior margins. Six central muscle scars present: 2 elongated ones on the dorsal sides, 2 pairs of nearly rounded scars below. Antennula with 2 long natatory setae, and few reduced ones. Male antenna with subterminal segment only 1 Vi times as long as wide, undivided. Sexual dimorphism in apical chaetotaxy of antenna apparent: only zl a large claw and both G1 and G3 small claws in males; 3 z-setae present and Gl-3 large claws in females. Hemipenis with lobe “a” bluntly pointed, lobe “h” swollen and produced; internal anatomy with post-labyrinthal spermiductus showing an extra coil in relaxed condition, part e ( — bursa copulatrix?) cup-shaped. Both prehensile palps consisting of one segment, asymmetrical: right palp wide and with 2 claw-like lateral processes; left palp narrower, straight over most of length, with one stout claw-like lateral process and one less solid process. Type locality: Figured specimens: Diagnosis: Explanation of Plate 19, 50 Fig. 1, 9 car., dors. (OC1590, 776 pm long); fig. 2, 9 LV, ext. lat. (OC1592, 116 pm long); fig. 3, 9 RV, ext. lat. (OC1592, 741 pm long); fig. 4, 9 car., vent. (OC1590, 116pm long). Scale A (200 /tm; x70), figs. 1-4. Stereo-Atlas of Ostracod Shells 19, 51 Pseudocandona gajewakajae (3 of 8) Remarks: Mazepova (1990, op. cit. All pp.) followed Bronstein (1947, op. cit. ,339 pp.; English translation, 1988, 470 pp.) in distinguishing 3 candonid genera in the endemic ostracod fauna of Lake Baikal: species with smooth valves (or with only weak pits in the centre of the valves) and with the endopodite of the male antenna with four segments and male bristles (Candona— 49 species); species with strongly sculptured valves and with the endopodite of the male antenna four-segmented, carrying male bristles (Baikalocandona — 1 1 species); and species with strongly sculptured valves and with the endopodite of the male antenna three- segmented and without male bristles (Pseudocandona— 28 species). Apart from the candonids, the fourth (and largest) endemic ostracod lineage in Lake Baikal belongs to Cytherissa (47 species). The allocation of a number of the endemic Baikal candonids to these three genera has been questioned by Damelopol (1978, Sber. ost. Akad. Wiss., (1), 187(1-5), 1-166) and by Broodbakker & Danielopol (1982, Bijdr. Dierk., 52, 103-120). Carbonnel (1969, op. cit.) created the genus Alatocandona in which he included P. gajewskajae. The history of the genus Pseudocandona Kaufmann, 1900 is complicated. For a discussion and a redefinition, see Damelopol (1978, op. cit.)', later discussions are in Danielopol (1978, Int. J. Speleol., 10, 57-71; and 1982, Bull. Mus. natn. Flist. nat. Paris, (4:4), 3-4, 369-396) and in Broodbakker & Danielopol (1982, op. cit.). According to these authors, the main features characteriz- ing this genus are the flat “M” part, with weakly sclerotized distal part of the hemipenis and aspects of the sexual dimorphism in the distal chaetotaxy of the antenna. Bronstein (1947/1988, op. cit.) was of the opinion that both European and Baikalian Pseudocandona have no sexual dimorphism in the antenna (neither in the divided penultimate segment, nor in the male bristles), and concluded that there was a close relationship between both faunas. Broodbakker & Danielopol (1982, op. cit.) argued against this, stating that some groups within the genus clearly show a sexual dimorphism in other features of the distal chaetotaxy of this limb. Such differences are now also illustrated from two Baikalian species (P . gajewskajae, herein, and P. ceratina Mazepova (see K. Martens, I. Noskova & G. Mazepova, Stereo-Atlas Ostracod Shells 19, 41-48, 1992). However, it becomes clear from the present redescriptions, different patterns in antennal chaetotaxy can also be found within the Baikalian fauna. This must indicate that the Pseudocandona problem requires more than a simple comparison between European and Baikalian species, in order to solve it. It would seem that the apparent polyphyletic nature of Pseudocandona can only be investigated by thoroughly re- examining all European and Baikalian representatives, with special reference to antennal chaetotaxy and internal anatomy of the hemipenes. The pattern of distal chaetotaxy presently described for the two Baikalian taxa here, may indeed also be present in other species of the Candoninae. Distribution: Recent, freshwater, Lake Baikal. Acknowledgement : See under Stereo-Atlas of Ostracod Shells 19, 43, 1992. Explanation of Plate 19, 52 Fig. 1, 9 LV, int. lat. (OC1593, 810/rm long); fig. 2, 9 RV, int. lat. (OC1593, 116pm long); fig. 3, 9 RV, int. lat., detail of adductor muse. sc. (OC1593); fig. 4, 9 car., vent., detail of overlap (OC1590); fig. 5, 9 car., vent., detail of surface structure (OC1590), fig. 6, 9 LV, int. lat., detail of ant. margin (OC1593). Scale A (200 pm; x70), figs. 1,2; scale B (25 pm; x540), fig. 3; scale C (25 pm; x425), fig. 4; scaleD(5/rm; x2,200), fig. 5; scale E (50 pm; x230), fig. 6. Stereo-Atlas of Ostracod Shells 19, 50 Pseudocandona gajewskajae (2 of 8) Stereo-Atlas of Ostracod Shells 19, 52 Pseudocandona gajewskajae (4 of 8) Stereo-Atlas of Ostracod Shells 19, 53 Pseudocandona gajewskajae (5 of 8) Text-fig. la-d, f-k, o* appendages (OC1597); le, cr appendage (OC1594): a, hemipenis; b, Tl; c, prehensile palp; d, prehensile palp; e, Mxl; f, Md-palp; g, idem., detail of seta si; h, idem., detail of gamma-seta; i, idem., detail of alpha-seta; j, idem., detail of beta-seta; k, T2. Scale bar = 78^/m for figs, la-d, f, k; 29 /am for figs, le, g-j. long); fig. 4, 9 antenna, detail. Scale A (200 //m; x70), figs. 1-3; scale B (10/rm; x 1,500), fig. 4. Stereo-Atlas of Ostracod Shells 19, 55 Pseudocandona gajewskajae (7 of 8) Text-fig. 2, appendages: a, cr, A2, detail of distal chaetotaxy (OC1597); b, 9, idem. (OC1598); c, o*, Md-coxa, detail (OC1594); d, cr, Md-coxa (OC1597); e, cr, Zenker organ (OC1597); f, cr, A1 (OC1597); g, cr, A2 (OC1597); h, cr, furca and furcal attachment (OC1597). Scale bar= 146 /am for fig. 2e; 78/um for fig. 2b, d, f-h; 29 /um for fig. 2a, c. Explanation of Plate 19, 56 Fig. 1, cr RV, ext. lat. (OC1597, 774 /am long), fig. 2, cr car. vent. (OC1596, 845 /im long), fig. 3, 9 antenna, detail. Scale A (200 /on; x70), figs. 1, 2; scale B (5//m; x3,000), fig. 3. Stereo-Atlas of Ostracod Shells 19, 54 Pseudocandona gajewskajae (6 of 8) Pseudocandona gajewskajae (8 of 8) Stereo-Atlas of Ostracod Shells 19, 56 Stereo-Atlas of Ostracod Shells 19 (13) 57-60 (1992) Semicytherura pulchra (1 of 4) 595.337.14 (119) (265.7 : 163.154.30+ 147.18): 551.352 ON SEMICYTHERURA PULCHRA (COLES & WHATLEY) by Michael A. Ayress & Thierry Correge (Department of Geology, The Australian National University, Canberra) Semicytherura pulchra (Coles & Whatley, 1989) 1986 Trinacriacy there cornuta sp. nov. G. Ciampo, Boll. Soc. paleont. ital., 24, 103, pi. 15, figs. 1-4, pi. 18, fig. 6. 1988 Rostrocythere? sp. R.C. Whatley & M.A. Ayress, Evolutionary biology of Ostracoda (Proc. 9th Int. Symp. Ostracoda, Shizuoka, 1985), pi. 1, figs. 2a, b, 3a, b. Kodansha & Elsevier, Tokyo & Amsterdam, etc. 1989 Mayburya pulchra gen. et sp. nov. G. Coles & R.C. Whatley, Revta esp. Micropaleont. , 21, 87, pi. 1, figs. 5-7. Holotype: Department of Earth Sciences, University of Naples, Italy no. COC n. 502. Type locality: Falconara section, Sicily. Globorotalia continuosa Zone, Tortonian, Late Miocene. Figured specimens: National Museum of Victoria, Melbourne, Australia nos. NMVP197914 (LV: PI. 19, 58, figs. 1-5) and NMVP197915 (RV: PI. 19, 60, figs. 1-4). Both from off east coast of Australia: NMVP197914 from Tasman Sea (lat. 29° 18.6' S, long. 154°4.534'E), water depth 1,989m, Bureau of Mineral Resources Rig Seismic core sample 71GC026, interval 19-20 cm; NVMP197915 from Coral Sea (lat. 18°07'S, long. 147° 36' E), water depth 1,007 m, Verna core sample V24-160, interval 35-36 cm. Quaternary. Explanation of Plate 19, 58 Figs. 1-5, LV (NMVP197914, 362 pm long); fig. 1, ext. lat.; fig. 2, int. lat.; fig. 3, int., ant. dors.; fig. 4, post, hinge; fig. 5, muse. sc. Scale A (100 //m; X 160), fig. 1; scale B (100 pm; x 150), fig. 2; scale C (50 ^m; x390), fig. 3; scale D (20 ^m; X 1,150), fig. 4; scale E (25 pm; X 800), fig. 5. Stereo-Atlas of Ostracod Shells 19, 59 Semicytherura pulchra (3 of 4) Diagnosis: Remarks: Distribution: A ckn o w led gem en ts: A species of Semicytherura with a regularly punctate median area but microreticulate, micro- punctate or smooth towards free margins. Four short anterior marginal spines and a longer postero-ventral spine in LV; the latter spine locates between two accommodating knobs on selvage in RV when valve is closed. “V”-shaped ventro-lateral ridge continuous with prominent antero- and postero-dorsal marginal ribs. Internal morphology characteristic of genus. Previous authors have placed this species within the Bythocytheridae having been strongly influenced by its artificial similarity to Pseudocy there. Well preserved specimens, shown here for the first time, clearly show four adductor scars and a complex inner lamella characteristic of Semicytherura. None of the previously described specimens from Italy or from the deep sea have had the proximal part of the calcarious inner lamella preserved. Ciampo’s (1986, op. cit.) name cannot be used for this species as it is a secondary junior homonym of Semicytherura cornuta (Brady) (1868, Trans. Linn. Soc. Lond., 26, 445). Late Miocene of Sicily (Ciampo, 1986); Late Oligocene to Recent of the North Atlantic (Coles & Whatley, 1989), Quaternary of the E Indian Ocean and SW Pacific (Whatley & Ayress, 1988; and herein). We would like to thank the Electron Microscope Unit of ANU for their assistance and use of their scanning electron microscopes. Prof. R.C. Whatley (UCW, Aberstwyth) commented helpfully on the manuscript. Explanation of Plate 19, 60 Figs. 1-4, RV (NVMP197915, 369^/171 long); fig. 1, post. vent, selvage; fig. 2, ext. lat.; fig. 3, int. lat.; fig. 4, ant. dors. Scale A (20 pm; x600), fig. 1; scale B (100 ^m; xl33), fig. 2; scale C (100 /rm; xl60), fig. 3; scale D (50 ^m; x480), fig. 4. Stereo-Atlas of Ostracod Shells 19, 60 Semicytherura pulchra (4 of 4) Stereo-Atlas of Ostracod Shells 19, 58 Semicytherura pulchra (2 of 4) ERRATA This paper appeared in ^4 Stereo-Atlas of Ostracod Shells 18 (pt. 2), 81-84, 1991 with pis. 18, 82, 84 unfortunately printed upside down. It is reprinted here with the plates in the correct orientation. The original pagination is retained should the subscriber wish to replace the original version with this correct copy. Stereo-Atlas of Ostracod Shells 18 (20) 81-84 (1992) Daleiella corbuloides (1 of 4) 595.337.21 (113.331) (420: 162.003.52): 55.351 +552.54 ON DALEIELLA CORBULOIDES (JONES & HOLL) by Robert F. Lundin & Lee E. Petersen (Arizona State University, Tempe & Anardarko Petroleum Corporation, Houston, U.S.A.) Genus DALEIELLA Boucek, 1937 Type-species (by original designation): Cythere corbuloides Jones & Holl, 1869 Diagnosis: Large, strongly inequivalved Pachydomellidae(?) with a perimarginal carina on the posteroventral, extending to the ventral surface and even to the anteroventral surface in some species, part of the admarginal surface of one or both valves. Overreach of the right by the left valve strong around entire periphery of the right valve, but especially strong dorsally and posteroventrally. Hinge parallel to longitudinal axis of valve. Shell wall without tubules or pore canals. Carapace width greater than height. Dimorphic)?) by posteriorward displacement of maximum width in heteromorph (presumed female). Remarks: This genus is similar in general appearance to pachydomellids but the combination of characters including the perimarginal carinae, strong overreach, great carapace width, orientation of the hinge and absence of tubules and pore canals distinguish it from the most similar genera Microcheilinella Geis, 1933, Tubulibairdia Swartz, 1936 and Newsomites Morris & Hill, 1952. The genus is represented by the type-species, D. corbuloides (Jones & Holl, 1869), from the Silurian of Great Britain and Podolia and the following species from the Silurian of Podolia and/or the East Baltic area: D. acutifinis Neckaja, 1960, D. acutifiniformis = M. acutifiniformis Abushik, 1979, and D. ianica Neckaja, 1960. The existence of the diagnostic generic charac- ters in D. triangularis Boucek, 1937 have not been verified and D. americana Morris & Hill, 1952 is most probably a Krausella Ulrich, 1894. D. ? canadensis Copeland, 1962, D. caleyi Copeland, 1973 and D. deubeli Zagora, 1967 have little in common with the type-species and certainly do not belong to Daleiella. The placement of Daleiella and other similar genera without tubules in the Pachydomellidae Berdan & Sohn, 1961 is open to question and would necessitate redefinition of that family. Discussion of suprageneric systematics of this large group of superfi- cially similar genera is beyond the scope of this paper. It is clear, however, that if the presence of tubules is considered to be of less than familial significance, Daleiella can be placed with Tubulibairdia, Microcheilinella, Newsomites and others in one family of the Bairdiacea. Explanation of Plate 18, 82 Figs. 1-3, car. (ASU X-128, 959 pm long): fig. 1, ext. rt. lat.; fig. 2, ext. post.; fig. 3, ext. dors. Fig. 4, car., ext. It. lat. (ASU X-129, 1071 long). Scale A (200 jrm; x53), figs. 1-3; scale B (200 /tm; x48), fig. 4. Stereo-Atlas of Ostracod Shells 18, 83 Daleiella corbuloides (3 of 4) Daleiella corbuloides (Jones & Holl, 1869) 1869 Cythere corbuloides sp. nov. T.R. Jones & H.B. Holl, Ann. Mag. nat. Hist., (4), 3, 211, pi. 15, figs. 4, 5. 1887 Xestoleberis corbuloides (Jones & Holl); T.R. Jones, Ann. Mag. nat. Hist., (5), 19, 410. 1892 Xestoleberis corbuloides (Jones & Holl); J. Smith, Trans, nat. Hist. Soc. Glasg., 3, 158. 1934 Microcheilinella corbuloides (Jones & Holl); R. S. Bassler & B. Kellett, Spec. Pap. geol. Soc. Am., 1, 412. 1937 Daleiella corbuloides (Jones & Holl); B. Boucek, Mem. Soc. r. Sci. Boheme, 1936(2), 7. 1952 Daleiella corbuloides (Jones & Holl); R. W. Morris & B. W. Hill, Bull. Am. Paleont., 34, 13. 1960 Tubulibairdia? corbuloides (Jones & Holl); I.G. Sohn, Prof. Pap. U.S. geol. Surv., 330-A, 75. 1961 Daleiella corbuloides (Jones & Holl); R.H. Shaver, Treatise on Invertebrate Paleontology, Q, 385, fig. 310A, 5. 1979 Microcheilinella mukschensis sp. nov. A.F. Abushik, Ezheg. vses paleont. Obshch., 22, 51, pi. 3, figs. 1, 2. 1991 Daliella [src] corbuloides (Jones & Holl); R.F. Lundin, L.E. Petersen & D.J. Siveter, J. Micropalaeont., 9 (2 for 1990), 179, pi. 1, figs. 5, 6. Designated herein. British Museum (Nat. Hist.) no. 12058; adult carapace. Jones & Holl 1869, pi. 15, figs. 4a-e. “Croft’s Quarry,” 0.5 km W of Malvern, Hereford & Worcester, England; approximately Nat. Grid Ref. SO 757 464, lat. 52°08'N, long. 2° 18'W. Much Wenlock Limestone Formation, Wenlock Series, Silurian. Department of Geology, Arizona State University (ASU), nos X-128 (PI. 18, 82, figs. 1-3), X-129 (car.: PL 18, 82, fig. 4), X-195 (car.: PI. 18, 84, fig. 6), X-196 (car.: PI. 18, 84, fig. 5). British Museum (Nat. Hist.), no. 1 2058 (lectotype, car.: PI. 18, 84, figs. 1-4). The lectotype and ASU X-195 are from the type locality. ASU X-128 and X-129 are from Harley Hill (A458) road cutting, 1 .2 km NW of Much Wenlock, Shopshire, England (Nat. Grid Ref. SJ 6103 0036) and ASU X-196 is from an exposure along path just above old railway track, S side of River Severn and about 400 m W of Browers Brook, Benthall Edge, Shropshire (Nat. Grid Ref. SJ 6635 0355); all three from Farley Member, Coalbrookdale Formation, Wenlock Series. Daleiella with a short perimarginal carina on the posteroventral admarginal surface of both valves and on the anteroventral admarginal surface of the right valve. Surface smooth. Possible dimorphism in this species is suggested by differences in the position of greatest width (compare PI. 18, 84, figs. 5, 6). Data are not available at this time to demonstrate if this difference is due to normal variation or dimorphism because large single- sample populations have not been found. Comparison of Abushik’s (1979) figures and specimens she has supplied, with the British materials described here indicate that D. corbuloides is conspecific with Microcheilinella mukschensis Abushik, 1979. This extends the known geographic distribution of D. corbuloides, which heretofore was known only from the Welsh Borderland and English West Midlands (Lundin et al. 1991). Known from many samples of Late Wenlock, Homerian, age and from one sample (locality no. 59 of Lundin et al. 1991) of Ludlow, early Gorstian, age in the Welsh Borderland and English West Midlands, and from Late Wenlock stata of Podolia. We gratefully acknowledge the support of NATO, the National Science Foundation (Grant No. EAR-8200816) and the College of Liberal Arts and Sciences, Arizona State University. Lectotype: Type locality: Figured specimens: Diagnosis: Remarks: Distribution: A ckno wledgements: Explanation of Plate 18, 84 Figs. 1-4, car. (lectotype, BMNH 12058, 1050/rm long): fig. 1, ext. rt. lat.; fig. 2, ext. vent.; fig. 3, ext. dors.; fig. 4, ext. It. lat. Fig. 5, car., ext. vent. (ASU X-196, 1053 pm long). Fig. 6, car., ext. vent. (ASU X-195, 1053 //m long). Scale A (200 /rm; x48), figs. 1-4; scale B (200 /tm; x49), figs. 5, 6. „ Stereo-Atlas of Ostracod Shells 18, 82 Daleiella corbuloides (2 of 4) Stereo-Atlas of Ostracod Shells 18, 84 Daleiella corbuloides (4 of 4) BPCC Blackpool COLOUR PRINTERS 0253 22351 Fax: 0253 295733 Stanley Road • Blackpool Stereo-Atlas of Ostracod Shells: Vol. 19, Part 1 CONTENTS 19 (1) 1-4 19 (2) 5-8 19 (3) 9-12 19 (4) 13-16 19 (5) 17-20 19 (6) 21-24 19 (7) 25-28 19 (8) 29-32 19 (9) 33-36 19 (10) 37-40 19 (11) 41-48 19 (12) 49-56 19 (13) 57-60 18 (20) 81-84 On Cytheropteron byjieldense Boomer & Bodergat sp. nov.; by I. Boomer & A.-M. Bodergat. On Pejonesia sestina (Fleming); by I.C.U. Hinz. On Tubupestis tuber Hinz & Jones gen. et sp. nov.; by I.C.U. Hinz & P.J. Jones. On Semiilia pauper Hinz gen. et sp. nov.; by I.C.U. Hinz. On Cuneoceratina exomata (Her rig); by E. Her rig. On Scaldianella simplex (Krause); by L.E. Petersen & R.F. Lundin. On Glyptopleuroides insculptus Croneis & Gale; by C.P. Dewey & J.E. Coker. On Glezeria belgica (Matern); by G. Becker & M. Coen. On Kanyginia hartmanni Schallreuter & Kanygin sp. nov.; by R.E.L. Schallreuter & A.V. Kanygin. On Fidelitella (Sibiritella) rara (Ivanova); by R.E.L. Schallreuter & A.V. Kanygin. On Pseudocandona ceratina Mazepova; by K. Martens, I. Noskova & G. Mazepova. On Pseudocandona gajewskajae Bronstein; by K. Martens, I. Noskova & G. Mazepova. On Semicythemra pulchra (Coles & Whatley); by MA. Ayress & T. Correge. ERRATA On Daleiella corbuloides (Jones & Holl); by R.F. Lundin & L.E. Petersen. 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