120 



J.A. ALLEN AND H.L. SANDERS 



Fig. 29. Tmdariopsis aeolata. a, internal morphology as seen from the 

 right side of a specimen from Knorr station 301 from the Guyana Basin; 

 b, the form of the hind gut on the left side of the body. For identification 

 of the parts see text-figure 8, p.. Scale = 1mm. 



whether the difference warrents generic status. Other protobranch 

 genera show an array of hind gut morphologies (e.g. Yoldiellidae, 

 Allen, 1992; Allen, Sanders and Hannah, 1995) which we believe 

 relate to changes in the benthic food resource as depth increases. For 

 this reason we are reluctant to erect a new genus when in other 

 respects T. aeolata is clearly within the genus Tindariopsis. 



Subfamily Nuculaninae Allen and Sanders 1982 



The subfamily is defined by Allen and Hannah ( 1 986) and comprises 

 three genera Nuculana, Propeleda and Adrana. 



Genus NUCULANA Link 1807 



TYPE SPECIES. Area rostrata Gmelin 1791 = Area pernula Miiller 

 1779. OD. 



Shell robust, moderately elongate, concentric sculpture, occa- 

 sionally with radial ribs, slightly rostrate, usually bicarinate; umbo 

 anterior; postero-dorsal margin straight or somewhat concave, pos- 

 terior margin may be slightly sinuous; escutcheon present; no 

 internal ridge from umbo to posterior margin; hinge moderately 

 robust, teeth chevron-shaped; ligament small, for most part internal, 

 usually amphidetic and vertical, sometimes posteriorly oblique. 



Genus PROPELEDA Iredale 1924 



Type SPECIES. Leda ensicula Angas 1 877. OD. 



Shell very elongate, thin, glossy, concentric sculpture may be ill- 

 defined, 3/4 shell post-umbonal, usually with two marked carinae 

 from umbo to upper and lower limit of rostrum, posteriorly truncate; 

 umbo small; postero-dorsal margin concave, postero- ventral margin 

 not sinuous; internal ridge usually from umbo, skirts ventral margin 

 of posterior adductor to posterior margin, second ridge may be 

 present from hinge plate to rostral margin; hinge plate slender, hinge 



teeth chevron-shaped, one or both arms of the chevron may be 

 elongate, anterior tooth series curve round the outer margin of the 

 anterior adductor, posterior series extends posterior to adductor; 

 ligament in large part internal, opisthodetic and oblique. 



Genus ADRANA Adams & Adams 1858 



Type SPECIES. Nucula lanceolata Lamarck 1819. SD Stoliczka 

 1871. 



Shell extremely elongate, slender, lanceolate, fragile, smooth or 

 with fine concentric and sometimes oblique sculpture, without 

 carinae, glossy; umbo almost central, barely raised; escutcheon 

 elongate, flattened, narrow; postero-dorsal margin straight, antero- 

 dorsal margin slightly convex, postero- ventral margin sinuous; hinge 

 plate slender, hinge teeth fine, obtuse, chevron-shaped;chondrophore 

 present; ligament internal, amphidetic. 



Nuculana acuta (Conrad 1831) 



TYPE specimen. Lectotype here designated, chosen from ANSP 

 30613, remainder of lot designated paralectotypes. 



Cited specimen. BMNH 1995055. 



Type locality. Tertiary fossil beds, near Suffolk, Virginia. 



Nucula acuta Conrad 1 83 1 , 32, pi. 6, fig. 1 . 

 Nucula cuneata Sowerby 1833, 198. 

 Nucula carinata H.C.Lea 1843, 163, (non M'Coy 1844). 

 ?Leda jamaicensis d'Orbigny 1846, 263, pl.XXIV, figs 30-32. 

 ?Leda inornata A.Adams 1856, 48. 

 Leda unca Verrill 1880, 401, (?non Gould 1862). 

 Leda acuta Dall 1886, 251, pl.7, figs 3a, 3b and 8. 

 Nuculana acuta Morris 1951, 7, pi. 6, fig. 2. 



Material: 



Cruise 



Sta 



Depth No 



(m) 



Lat 



Long 



Date 



Gear 



NORTH AMERICA BASIN 



Atlantis CI 97 2+2v 40*20.5'N 70"47.0'W 25.5.61 AD 



264 



Atlantis Slope 200 8+6v 40'01.8'N 70"42.0'W 28.8.62 AD 



283 sta.2 



Atlantis II 114 197 8 40"04.1'N 70°27.8'W 15.8.66 ES 



24 



Atlantis II 172 119 7+2v 40'12.3'N 7044.7'W 27.1 1.67 ES 



40 173 123 4 40'10.8'N 70"43.6'W 28.1 1.67 ES 



The type specimens have been examined by JAA. 



Conrad (1831) described this species from fossils obtained from 

 the Miocene beds near Suffolk and the banks of the James and York 

 rivers, Virginia. He later redescribed the species (Conrad, 1845) 

 adding that he had found Recent specimens in deep water in the Gulf 

 of Mexico. His first account refers to specimens being in 'Cabinet of 

 the Acad. Nat. Sciences, No. 1738.' This reference does not corre- 

 spond with any lot of N. acuta. Recent or fossil, in the Academy of 

 Natural Sciences, Philadelphia today. There are specimens in the 

 Invertebrate Paleontology collection of the Academy (catalogue 

 number 30613) that up to now have been considered as possible 

 syntypes of the species. The lot comprises 4 right valves, 3 left 

 valves 1 left and 1 right broken valve, 1 intact shell, 1 shell with 

 rostrum tip missing and 3 fragments. These specimens, labelled by 



