LAMELLIBRANCHIATA. 



19 



Nor can I believe, that the shells of this species stated to have been taken off the west coast of 

 France, 748—1262™. ("Princesse Alice") and in the Bay of Biscay, 400 m. ("Caudan") were "fresh" 

 — nnfortunately, the authors say nothing as to the condition of the shells — though Locard makes 

 the following statement regarding P.islandicns : "C'est, comme on le sait, une espece particulierement 

 septentrionale, qui ne vient jusque dans nos regions qu'a la condition de se propager en eaux 

 profoudes".') 



Pecteti islandiats is not a particularly high-arctic species; it lives in greatest quantity, forming 

 whole banks of shells, at Finmarken, North Iceland and South-West Greenland as well as on the 

 fishing banks of Nova Scotia and Newfoundland, whereas it occurs much more sparsely at Spitzbergen ^). 

 Morch also remarks, that it does not grow so large in the high norths). As mentioned, it attains a 

 considerable size even so far south as S. W. Iceland, where the bottom-temperature in August 

 amounted to 9.3° C. 



Pecten aratus Gmelin. 

 PI. I, figs. 5a — e. 

 Pecten arafns Gmelin, Linn. Syst. Nat. ed. 13, 17S8, p. 3327. 



Pecten silica t us Jeffreys, 



Brit. Conchol. II, 1863, p. 64; Proc. Zool. Soc, 1879, p. 557 

 Norv. 1878, p. 17, Tab. 2, fig. 3. 



The "Ingolf Expedition has taken this species at: 



St. 98. W. of Iceland 138 fm. 



- 97- - - - 



- 89. - - - 



- 9. S.W. - — 



- 10. - - — 



- 85. - - - 



- 55-S.E.- - 



Pcctoi aratus Sars, Moll. Reg. Arct. 



At Iceland and the Faeroes — where it has not been known hitherto — it has also been 

 taken at the following places by Danish expeditions: 



64=42' N.L., 27°43' W.L 426 fm. 6' C. 



63=15' — 22^^23' - 170-114 - 



20°7' — 293 - 



2o"o6' — 268 - 



9°35' — ca. 475 - 



63=05' - 

 63=12.5' 



61=15' 



I spec. 



1 — 



2 — & 13 valves, 

 ca. 20 spec. 



I spec. 



The specimens to hand are rather variable both in form and sculpture. As a rule the height is 

 somewhat greater than the length, but the two dimensions may be almost equal. In consequence of 

 this the circumference is variable, the lower contour forming sometimes a part of an oblique oval, some- 

 times an almost perfect arc of a circle. The number of the primary, stronger ribs is extremely variable 



1) Campagne du "Caudan", par R. Koehler, 1S96, p. 207. 



2) Torell: Spitsbergens MoUuskfauna, 1S59, p. 124. 



3) Catal. des Moll, du Spiteberg, p. 27. .\nn. Soc. Mai. de Belgique, IV, 1869. 



3* 



