jj5 lamellibranchiata. 



The ribbing ma>' also be subject to some variation, in regard to denseness and strength. 

 This variety is common at West Greenland; apart from the "Ingolf stations mentioned 

 before I have seen specimens from the following localities: 



Julianehaab. 



Month of AmeraHk Fjord (as a short, convex, rather denseh* ribbed form). 



66°49' ^- L., 56°28' W. L 235 fm., sand and ooze. 4.4° C. 



Disko Bay 65 - 



Quite a number of the localities which Posselt notes from West Greenland under Astartc 

 crcnafa Gray (Medd. om Gronland, XXIII, 1898, p. 64), also refer probably to the \m&ty siib(rtjuilaf<ra. 

 — The largest specimens are 30 "'"'. long. 



At Jan Ma yen, in addition to at the "Ingolf" St. 115, it has been taken by the Danish 

 Expedition of 1900 at a depth of 55 fm., on ooze mixed with coarser material. The Austrian Polar 

 Station took it on the north side of the island, at a depth of 75 — 95 fm. (Becher I.e. p- 70). The 

 maximum length is 30 """. 



From Denmark vStrait there is a single valve from 64^42' N. L., 27°4o' W. L., 426 fm. (W. of 

 Iceland). 



Var. crcbricostata Mc. An dr. & Forbes. 

 PI. IV, figs. 5 f and g. 



Astartc crcbricostata Mc. Andr. & F'orbes, Ann. Mag. Nat. Hist. XIX, 1847, P- 9^, PI- 9, fig4; Forbes 

 & Hanley, Brit. Moll. I, 1853, p. 456, PI. 30, fig. 9; Sowerby, Thes. Conch yl. II, 1855, p. 

 780, PI. 167, fig. 10; Reeve, Conchol. Icon. XIX, 1874, Astartc, sp. 10, PI. 2, fig. 10; Sars, 

 Moll. Reg. Arct. Norv., 1878, p. 54, PI. 5, fig. 7. 



In this variety the ribbing is very like that in the foregoing, but the shell is in general more 

 triangular or oval-cordiform and has the umbones moved more in front. It is however very close to 

 the var. subccqiiilatcra and cannot always be kept separate from this. 



It occurs at North and East Iceland, whence we have it from the following localities: 



Skagestrands Bugt 119 fm. 5 spec. 



66°i7'N.L., i8°i3'W. L 52- i — 



Husavik in E. by S 47 — 58 - i — 



Thistil Fjordr 5° - i clay with many stones. 4 — &. 85 valves. 



66''32'N.L., i5"i5W. L 75 - 3 valves. 



Bakkafjordr 52—43 - , clay mixed with sand. i spec. 



Seydisfjordr 50—20 - i — 



— 38— 14 - , mud. 



The largest sijecimen is 31 """. long. 



