64 



J.A. ALLEN, H.L. SANDERS AND F. HANNAH 



GUYANA BASIN 



Knorr 25 



287 



288 



291 



306 



307 



31 



3356 



4980- 



4934 



4417- 



4429 



3859- 155 



3868 



3392- 38 



3429 



3862- 30 



3835 



38°17.6'N 70°22.8'W 



13°16.0'N 

 13°15.8'N 

 11°02.2'N 

 11°03.8'N 

 10°06.1'N 

 10°06.6'N 

 9°31.1'N 



12°34.4'N 

 12°40.8'N 



54°52.2'W 

 54°53.1'W 

 55°05.5'W 

 55°04.8'W 

 55°14.0'W 

 55°15.4'W 

 56°20.6'W 



58°59.3'W 

 59°09.2'W 



ES 24. 2.72 



ES 25. 2.72 



ES 26. 2.72 



ES 2. 3.72 



ES 3. 3.72 



ARGENTINE BASIN 

 Atlantis II 259 3305- 

 60 3317 



30 37°13.3'S 52°45.0'W ES 26. 3.71 



WEST EUROPEAN BASIN 

 Chain 106 316 2173- 85 

 2209 

 318 2506 106 



Jean Charcot 

 (Polygas) 

 (Biogas II) 

 (BiogasIII) 



(Biogas IV) 



(Biogas V) 

 (Biogas VI) 



(Incal) 



321 



323 



DS23 

 DS25 

 DS31 

 DS37 

 DS71 

 DS51 

 DS52 

 DS53 

 DS54 

 DS58 

 DS62 

 DS63 

 DS64 

 CV38 

 DS68 

 DS71 

 DS74 

 DS78 

 DS79 

 CP10 

 DS01 



2290- 94 

 2968 



3356- 6 

 3338 



4734 1 

 2096 2v 

 2813 11 



2110 

 3546 



2430 27 



2006 

 4425 

 4659 

 2775 

 2175 

 2126 

 2156 

 2695 

 4550 

 2194 



1 

 1 



1 



10 

 1 



1 



2 

 2 

 1 

 2 



2777 2+2v 



4706 1 



4715 2 



2878 1 



2091 73 



DS02 2081 67 



CP01 2068- 10 



2040 

 CP02 2091 2 



CP03 2466 4 



CP04 2483- 2 



2513 

 DS05 2503 123 



DS06 1494 243 



DS07 2884 267 



DS08 2891 32 



CP05 2884 58 



CP06 2888- 39 



2893 

 CP07 2896 17 



DS09 2897 274 



50°58.7'N 

 50°57.7'N 

 50°27.3'N 

 50°26.8'N 

 50°12.3'N 



50°08.3'N 



46°32.8'N 

 44°08.2'N 

 47°32.5'N 

 47°31.8'N 

 47°28.3'N 

 44°11.3'N 

 44°06.3'N 

 44°30.4'N 

 46°31.3'N 

 47°34.1'N 

 47°32.8'N 

 47°32.8'N 

 47°29.2'N 

 47°30.9'N 

 46°26.7'N 

 47°34.4'N 

 47°33.0'N 

 46°31.1'N 

 46°30.4'N 

 47°29.6'N 

 57°59.7'N 

 57°59.2'N 

 57°58.8'N 

 57°58.5'N 

 57°57.7'N 

 57°56.4'N 

 57°58.4'N 

 57°57.7'N 

 56°33.2'N 

 56°32.5'N 

 56°33.2'N 

 56°31. 5'N 

 56-28. l'N 

 56-27.6'N 

 56°26.6'N 

 56°25.9'N 

 55°00.7'N 

 55°01. 0'N 

 55°02.0'N 

 55°01. 9'N 

 55°00.4'N 

 55°00.9'N 

 55°02. 3'N 

 55°02.6'N 

 55°03.4'N 

 55°04.4'N 

 55°07.7'N 

 55°08. l'N 



13°01. 6' W 

 13°01. 3' W 

 13°20.9'W 

 13°19.9'W 

 13°35.8'W 



13°53.7'W 



13°50.9'W 



10°21. 0'W 



4°15.7'W 



9°04.2'W 



8°34.6'W 



9°07.2'W 



4°15.4'W 



4-22.4'W 



4-56.3'W 



10°29.1'W 



9°08.2'W 



8°40.0'W 



8°35.0'W 



8°30.7'W 



8°59.5'W 



10°23.9'W 



8°33.8'W 



9°07.8'W 



10°23.8'W 



10°27.1'W 



9°04.5'W 



10°39.8'W 



10-41.3' W 



10-48.5'W 



10°49.2'W 



10°55.0'W 



10°42.8'W 

 10°44.6'W 

 11°11.3'W 

 11°12.4'W 

 11°11.3'W 

 11°12.4'W 

 11°11.7'W 

 11°12.0'W 

 11°10.5'W 

 11°10.7"W 

 12°31. 0'W 

 12°32.0'W 

 12°34.6'W 

 12°33. 4"W 

 12°29.4'W 

 12°31.1"W 

 12°40.3"W 

 12°41. 7'W 

 12°46.4'W 



12°52.6'W 

 12°53.2'W 



ES 18. 8.72 



ES 19. 8.72 



ES 20. 8.72 



ES 21. 8.72 



DS 26. 



DS 1. 



DS 19. 



DS 24. 



DS 28. 



DS 18. 



DS 18. 



DS 19. 



DS 21. 



DS 23. 



DS 26. 



DS 26. 



DS 26. 



CV 24. 



DS 19. 



DS 20. 



DS 21. 



DS 25. 



DS 26. 



CP 21. 



DS 15. 



10.72 



11.72 



4.73 



8.73 



8.73 



2.74 



2.74 



1.74 



2.74 



2.74 



2.74 



2.74 



2.74 



2.74 



6.74 



10.74 



10.74 



10.74 



10.74 



10.74 



7.76 



DS 16. 7.76 



CP 16.7.76 



CP 16. 7.76 



CP 17. 7.76 



CP 17. 7.76 



DS 18. 7.76 



DS 18. 7.76 



DS 19. 7.76 



DS 19. 7.76 



CP 19. 7.76 



CP 19. 7.76 



CP 20. 7.76 



DS 20. 7.76 



CP08 2644 



49 



50°14.7'N 

 - 50°15.2'N 



13°13.5'W 

 13°14.8'W 



CP 



27. 



7.76 



DS10 2719 



48 



50°12.7'N 

 ■ 50°13.2'N 



13°16.6'W 

 13°16.4'W 



DS 



27. 



7.76 



OS01 2634 



794+ 

 52v - 



50°14.4'N 

 ■ 50°15.2'N 



13°10.9'W 

 13-11.0'W 



OS 



30. 



7.76 



WS01 2550- 39+2v 50°19.4'N 



13°08.1'W 



WS 



30. 



7.76 



2539 





■ 50°19.3'N 



13-06.0'W 









WS02 2498- 416 



50°19.3'N 



12°55.8'W 



ws 



30. 



7.76 



2505 





- 50°20.0'N 



12°56.0'W 









CP10 4823 



1 



48°25.5'N 

 - 48°26.3'N 



15°10.7'W 

 15°09.8'W 



CP 



31. 



7.76 



DS11 4823 



1 



48°18.8'N 

 - 48°13.6'N 



15°11.5'W 

 15°12.0'W 



DS 



1. 



8.76 



WS03 4829 



5+lv 



48°19.2'N 



15°23.3'W 



WS 



1. 



8.76 



CPU 4823 



2 



48°20.4'N 

 ■ 48°21. l'W 



15°14.6'W 

 15°13.7'W 



CP 



1. 



8.76 



OS02 4829 



4 



48°19.2'N 



15°15.7'W 



OS 



2. 



8.76 



DS14 4254- 



1 



47°32.8'N 



9°35.4"W 



DS 



7. 



8.76 



4248 















DS16 4268 



1 



47°29.8'N 

 • 47°30.3'N 



9°33.4"W 

 9-33.4'W 



DS 



9. 



8.76 



CANARY BASIN 















Discovery 6704 2129 



17 



27°44.9'N 



14°25.0"W 



ED 



17. 



3.68 



CAPE VERDE BASIN 















Discovery 8521 3053- 



90 



20°46.9'N 



18°43.4'W 



WS 



25. 



6.74 



3058 





■ 20°47.6'N 



18°53.5'W 









8521 3064- 



52 



20°47.9'N 



18°53.4'W 



WS 



26. 



6.74 



307 





■ 20°48.6'N 



18°53.4'W 









8532 3112- 



36 



13°47.8'N 



18°14.0'W 



WS 



5. 



7.74 



3119 





■ 13°48.0'N 



18°14.8'W 









8532 2952- 



20 



13°48.2'N 



18°08.0'W 



WS 



5. 



7.74 



2958 





13-47.6'N 



18 o 07.5'W 









ANGOLA BASIN 

 Atlantis II 197 4592- 

 42 4597 



CAPE BASIN 



Jean Charcot DS06 4585 



(Walvis) 



35 10°29.0'S 9°04.6'E ES 21. 5.68 



1 33°34.5'N 2°32.9'E DS 31.12.78 



Shell description (Figs. 101-103). Shell ovate, somewhat 

 inflated, inequilateral, fragile, frequently with broad, 

 opaque, concentric banding which is variable in form; umbo 

 inflated, anterior in position, orientated medially; dorsal shell 

 margins slope gently from umbo, antero-dorsal, anterior and 

 antero-ventral margins form a smooth curve, anterior limit of 

 which lies dorsal to the mid horizontal line, ventral margin 

 smoothly curved, with posterior limit of shell also dorsal to 

 mid horizontal line, postero-dorsal margin slightly convex, 

 slope increases moderately sharply at posterior limit of hinge 

 plate to join posterior margin to form slight subrostration; 

 hinge plate, stout, with relatively large chevron-shaped teeth, 

 posterior series with one or two more teeth than anterior 

 series (maximum 10 in posterior series), teeth extend as far as 

 the anterior and posterior margins of anterior and posterior 

 adductor muscles respectively, hinge plate lies close to shell 

 margin below umbo; ligament moderately sized, amphidetic, 

 'saddle'-shaped in lateral view, extends below hinge plate. 



Prodissoconch length: 187-198 u.m. Maximum recorded 

 shell length: 3.7 mm. 



The species has a high degree of variation in shape and 

 within a population may range from the form described above 

 (the most common) to a more quadrangular outline in which 

 the deepest part of the ventral margin instead of being 

 approximately central is posterior to vertical line through the 

 beaks (Fig. 104). Such specimens may be more inflated. 



