DEEP-SEA PROTOBRANCHIA (BIVALVIA) 



33 



Fig. 43 Yoldiella biscayensis . Lateral view from the right side of 

 the internal morphology of a specimen from Sta. BG VI DS76 

 West European Basin. (Scale = 1.0 mm). For identification of the 

 parts see Fig. 34. 



possible to identify which of the two is L. lata. We have 

 separated the two species and chosen lectotypes from the 

 'Valorous' material. 



Material. 



Cruise 



Sta DepthNo 

 (m) 



Lat 



Long 



Gear Date 



WEST EUROPEAN BASIN 



Sarsia 



44 1739 



18 



43°40.8'N 



3°35.2'W 



ED 



16. 



7.67 





65 1922 



25 



46°15.0'N 



4 o 50.0'W 



ED 



25. 



7.67 



La Perle 

















(Biogas I) 



DS06 

 DS07 



3 

 2 















DS11 2205 



8 



47°35.5'Ne 



8-33.7' 



WDS 8. 



8.72 





DS12 2180 



2 



47-28.5 'N 



8-35.5'W 



DS 



9. 



8.72 





DS13 2165 



5+lv 



47°33.7'N 



8°39. 9'W 



DS 



9. 



8.72 





OS01 



2v 







OS 







Chain 106 



313 1491- 

 1500 



457 



51°32.2'N 



12 35.9'W 



ES 



17. 



8.72 





316 2173- 1653 



50°58. 7' N 



13°01. 6'W 



ES 



18. 



8.72 





2209 















Jean Charcot 















(Polygas) 



DS15 2246 



8 



47°35. 2'N 



8°40. l'W 



DS 



21. 



10.72 





DS16 2325 



1 



47°36. l'N 



8°40.5'W 



DS 



21. 



10.72 





DS18 2138 



10 



47°32. 2'N 



8°44.9'W 



DS 



22.10.72 





DS25 2096 



255 



44°08. 2'N 



4°15. 7'W 



DS 



1. 



11.72 





DS26 2076 



1095 



+ 17v 



44°08.2'N 



4°15.0'W 



DS 



1. 



11.72 





CV10 2108 



2 



47°30. 7 'N 



8 o 40.6'W 



CV 



22.20.72 



Jean Charcot 















(Biogas II) 



DS32 2138 



26 



47°32. 2'N 



8°05.3'W 



DS 



19. 



4.73 



(Biogas III) 



DS35 2226 



9 



47°34.4'N 



8°40.7'W 



DS 



24. 



8.73 





DS36 2147 



7 + 2v 



47°32.7'N 



8°36.5'W 



DS 



24. 



8.73 





DS37 2110 



12+2v 47°31.8'N 



8°34.6'W 



DS 



24. 



8.73 





DS38 2138 



13 



47°31.5'N 



8-35.8'W 



DS 



25. 



8.73 





DS49 1845 



177+ 

 25v 



44 o 05.0'N 



4°15.6'W 



DS 



1. 



9.73 





DS50 2124 



153+ 

 61v 

 421 + 



44°09.9'N 



4°15. 9'W 



DS 



1. 



9.73 



(Biogas IV) 



DS51 2430 



44°11.3'N 



4-15.4'W 



DS 



18. 



2.74 







lOlv 















DS52 2006 



183+ 

 190v 



44-06.3 'N 



4°22.4'W 



DS 



18. 



2.74 





DS61 2250 



3 



47°34.7' N 



8°38.8'W 



DS 



25. 



2.74 





DS62 2175 



48+ lv 47°32.8'N 



8°40.0'W 



DS 



26. 2.74 



Jean Charcot DS64 2156 



12 + 



47°29.2'N 



8°30.7'W 



DS 



26. 2.74 







14v 













CV33 1913 



1 



44°04.6'N 



4°18. l'W 



CV 



18. 2.74 





CP01 2245 



19+4v 47°34. 6'N 



8°38.8'W 



CP 



25. 2.74 



(Biogas V) 



DS70 2150 



6 



44°08. 8'N 



4°17.4'W 



DS 



21. 6.74 





CP07 2170 



136+ 



4v 

 19 



44°09.8'N 



4°16.4'W 



CP 



21. 6.74 



(Biogas VI) 



DS71 2194 



47°34.4'N 



8 33.8'W 



DS 



20.10.74 





DS86 1950 



325 + 

 13v 



44°04.8'N 



4°13.7'W 



DS 



31.10.74 





DS87 1913 



550+ 



4v 



40+2\ 



44°05.2'N 



4°19.4'W 



DS 



1.11.74 





DS88 1894 



' 44°05.2'N 



4°15. 7'W 



DS 



1.11.74 





CP08 2177 



12+lv44°33.2'N 



8°38.5'W 



CP 



20.10.74 





CP09 2171 



34 



47°33.0'N 



8°44. l'W 



CP 



20.10.74 





CP24 1995 



23 



44°08. l'N 



4-16.2'W 



CP 



31.10.74 



Jean Charcot CP01 2068- 



29 



55°57.0'N 



10°55.0'W 



CP 



16. 7.76 





2040 













(Incal) 



CP02 2091 



4 



57-58.4'N 

 ■ 57°57.7'N 



10°42.8'W 

 10°44. 6'W 



CP 



16. 7.76 





CP08 2644 



1 



50°14.7'N 



13-13.5'W 



CP 



27. 7.76 





- 





50°15.2'N 



13°14.8'W 









OS01 2634 



2 



50°14.4'N 

 ■ 50°15.2'N 



13°10.9'W 

 13 o 11.0'W 



OS 



30. 7.76 





DS01 2091 



234 



57°59.7'N 

 ■ 57°59.2'N 



10 o 39.8'W 

 10-41.3'W 



DS 



15. 7.76 





DS02 2081 



262 



57°58.8'N 

 ■ 57-58.5'N 



10°48.5'W 

 10°49.2'W 



DS 



16. 7.76 





DS05 2053 



7 



56°28. l'N 

 ■ 56-17.6'N 



11°11.7'W 

 11°12.0'W 



DS 



18. 7.76 





DS06 2494 



86 



56°26.6'N 

 56-15.9'N 



11°10.5'W 

 11°10.7'W 



DS 



18. 7.76 





WS01 2550- 



6 



50°19.4'N 



13°08.0'W 



WS 



30. 7.76 





2539 





50°19.3'N 



1 3°06.9' W 









WS02 2498- 



4 



50°19.3'N 



12 55.8'W 



WS 



30. 7.76 





2505 





50-20.0'N 



12°56.0'W 







CANARIES BASIN 



Discovery 6701 1934 9 27°45.2'N 14°13.0'W ED 16. 3.68 



SIERRA LEONE BASIN 



Atlantis II 139 2099- 1 10°33.0'N 17°53.0'W ES 4. 2.67 

 31 2187 



Largely restricted to lower slope and abyssal rise depths in 

 the northeastern Atlantic, but predominantly in the West 

 European Basin with a few specimens taken in the Canaries 

 and Sierra Leone Basins. Depth range: 1491-3220 m. 



Shell description (Figs. 44 & 45). Shell transversely 

 ovate, fragile, inequilateral, postumbonal length 53-65% 

 of total length, moderately inflated, very fine concentric 

 lines forming ridges ventrally, more conspicuous in larger 

 specimens, irridescent, pale yellow/brown periostracum, 

 light and dark banding patterns; umbo moderately inflated, 

 inwardly directed; dorsal margin raised, anterior and pos- 

 terior margins smoothly curved with anterior margin more 

 convex than posterior, antero-dorsal margin short, joins 

 anterior margin in smooth curve, postero-dorsal margin 

 approximately straight, gradually inclining distally to pos- 

 terior limit of hinge plate, then curves sharply to posterior 

 margin, posterior margin more convex dorsally, ventral 

 margin smoothly curved; hinge plate narrow, anterior and 

 posterior hinge plates merge with margin below umbo, 

 teeth small, chevron-shaped, number on each plate 

 depending on size (up to 9/10), usually with one or two less 

 on anterior hinge plate; ligament amphidetic, small, inter- 

 nal rectangular in cross-section. 



Prodissoconch length: 198 u.m (average) range 190-220 

 u.m. Maximum recorded shell length: 4.43 mm. 



