Eucytherura Muller, 1894

Ayress, M. A., Whatley, R., Downing, S. E. & Millson, K. J., 1995, Cainozoic and from Recent Deep Sea Cytherurid Ostracoda the South Western Pacific and Eastern Indian Oceans, Part Cytherurinae, Records of the Australian Museum 47 (2), pp. 203-223 : 205-206

Eucytherura Muller, 1894

Type species. Cythere complexa Brady, 1867 .

Emended Diagnosis. A genus of the subfamily Cytherurinae with a small carapace of subrectangular, quadrate or subtriangular lateral outline. Ventral margin gently sinuous, often obscured by posteroventral tumidity or tubercle. Eye tubercle present or absent. Surface very ornate with reticulation, tubercles and ridges. Normal pore canals usually of two types: those emergent through mural pore conuli; and those arranged in groups through the solum of the reticulation. Muscle scars consist of four subovate adductor scars in a vertical row and a subreniform frontal scar ahead of the row. Hinge, in right valve, consists of a small but prominent circular or ovate tooth on anterior and posterior ends, with a finely locellate median groove very narrow at midlength and often flexured or sinuous.

Comparisons. Our concept of Eucytherura indicated in the above emended diagnosis allows us to synonymise Typhlocythere Bonaduce, Ciampo & Masoli, 1975 , Typhloeucytherura Colalongo & Pasini, 1980 and Parahemingwayella Dingle, 1984 . These three genera were proposed mainly to accommodate the fact that they differ from Eucytherura (as presently diagnosed by Weingeist, 1949) in lacking eyes. Deep sea taxa always lack eyes as a result of living in an aphotic environment. Consequently, this feature cannot be used to recognise genera in the deep sea. It may well be that blindness of these genera in shallow environments had preadapted them for deeper water existence, but we can find no consistent features which might reveal their separate generic identity. Previous workers have stressed the importance of certain features for generic identification such as inflation and outline, absence of dorsal ridges or tubercles and nature of ornament. We recognise these features as being variable in number or nature, and moreover, as occurring in variable combination in different species. For this reason, we prefer to retain species previously assigned to Parahemingwayella , Typhlocythere and Typhloeucytherura within Eucytherura . The latter genus can be separated from Hemiparacytheridea by virtue of its hingement, having a distinct ovate posterior terminal element, and its solum pore clusters.

Key to Deep-sea Species of Eucytherura

1.

--Normal pores large and regularly distributed, valve size small.................................................2

2. Weakly inflated; ornament predominantly reticulation.............................................. anoda

--Moderately well inflated; ornament of ridges and reticulation.................................................3

3. Alate; subcentral tubercle present; surface ridges distinct............................. E. polydictyota

--Not alate; subcentral tubercle absent; surface ridges diffuse............................... E. boomeri

4.

--Lateral outline subrhomboidal, subquadrate or subrectangular................................................. 8

5.

--Singleposteroventral swelling;surface stronglyspinose spinose...................................E. TODO elegantula

6. Subcentral tubercle high on lateral surface; deep concavity indorsalmargin.............................................................................................. Eucytherurasp.3

-- Posterodorsal tubercle or ridge present; strong anterior marginal rim..................................

.

--Posterodorsaltubercle orridge absent; weak anteriormarginal marginal TODO TODO TODO batalaria

7. Dorsal margin sinuous; reticulation well developed with extensive ventral microreticulation................................................................... E. parabatalaria

--Dorsal margin gently convex; reticulation relatively irregular with only poorly developed ventral microreticulation.......................................E. downingae

8. multituberculate

--Tubercles not well developed or absent....................................................................................9

9. I

10.

--Carapace moderately inflated, may have intrafossal spines .................................................l3

1 l. Reticulation spinose; short horizontal median ridge present............................................... 12

--Reticulation lacks spines; median ridge absent tumida

12. Lateral spines weakly developed; microreticulation present on anteroventralsurface E. indianensis

--Strongly spinose; ventral microreticulation absent.................................................. E. calabra

13.

14. Large bulbous posteroventral swelling; lacks a median ridge................... Eucytherura sp. 2

15. .....Fossal spincs abscnt................................................................. Eucytherura sp. aff. antipodum