DEEP-SEA PROTOBRANCHIA (BIVALVIA) 



125 



Fig. 37. Nuculana vestita. Lateral views of right side of four shells in outline to show differences in shape with increasing size. Specimens from Atlantis 

 II station 203 from the Angola Basin. Scale = 1mm. 



of the mantle edge. The anterior mantle sense organ is well- 

 developed. 



The foot is large with the margins of the sole finely papillate. The 

 palps are very small with up to 12 broad folds. The palp proboscides 

 are stout and elongate, even in the contracted state. The gills are 

 elongate and broad with up to 36 gill plates. 



Propeleda carpenteri (Dall 1881) 



Type specimen. Syntypes, USNM 63 1 5 1 and MCZ 7936-7938. 



Type locality. Off Barbados, 'Blake' stations 5, 9, and 21, 

 100fm-287fm. 



Cited specimens. BMNH 1995057 



Leda carpenteri Dall 1881, 125; 1886, 249, pi. 8, fig. 10, pl.9, fig.3. 

 Nuculana carpenteri Johnson 1934, 16. 



Material: 



Cruise 



Sta Depth No Lat 



(m) 



Long 



Date Gear 



ARGENTINE BASIN 



Atlantis II 237 993- 194 36"32.6'S 53'23.0'W 11.3.71 ES 

 60 1011 



239 1661- 8 36'49.0'S 53"15.4'W 11.3.71 ES 

 1679 



240 2195- 8 36°53.4'S 53"10.2'W 12.3.71 ES 

 2323 



Specimen USNM 63151 examined by JAA. 



Previously reported off N. Carolina, Gulf of Mexico and Eastern 

 Caribbean (Dall, 1889; Rice and Kornicker, 1965; James, 1970), the 

 present specimens are from the Argentine Basin. This species has a 



Fig. 38. Nuculana vestita. Internal morphology as seen from the right 

 side of a specimen from Atlantis II station 203 from the Angola Basin. 

 For identification of the parts see text-figure 7, p. 106. Scale = 1mm. 



somewhat unusual distribution from shelf to lower slope depths, 

 200-2323m 



Shell description (Figs 39^-1) 



Shell fragile, semi-transparent, slender, moderately elongate, rostrate 

 with two post umbonal carinae, ornamented with faint concentric 

 ridges; periostracum pale straw colour; umbos small, far anterior 

 (postumbonal length 60-68% of total length), inwardly facing; 

 antero-dorsal margin slightly flattened, ventral margin smoothly 

 curved, postero-dorsal margin raised, slightly sinuous, concave 

 proximally, convex distally, meets posterior margin at limit of dorsal 

 post-umbonal carina, posterior margin concave between posterior 



