88 



LAMELLIBRANCHIATA. 



Faxafjordr, off Kollafjordr 10 fm. ca. 25 spec. & 100 valves. 



, Keflavik 15 — 16 - 1 & 2 — 



, ca. 2 mil. N.E. of Keflavik 19 1 2 — 20 T / 2 - , ooze. 1 — 



, E. of Videy 9 — 10 - , fine sand and ooze. 3 — 



Reykjavik, Engey 7 — 8'/ 2 - , ooze. 1 fragment of a valve 



Hafnarfjordr. 1 valve. 

 25 - , fine black sand and ooze. 1 — 



On the northern part of the west coast C. groe.nlandicum is common and reaches the consid- 

 erable length of 80 n,m . As the above list shows, a considerable material has also been collected on 

 the southern part of the west coast (region of Faxafjordr); we might think, therefore, that the 

 species is also common on this part of the coast. It must be emphasized, however, that the living 

 specimens hitherto taken from the bottom of the sea are usually small (2 — 12 mm . long), and that the 

 separated valves accompanying them most often have an "ancient" appearance and do not reach any 

 great length either (at most 43 mm . long). From this, however, Hvalfjordr, with the Hvammsvik lying 

 en its south side, again forms an exception, as very large specimens have been taken here (up to 

 . in length) and containing the animals. The specimen from Keflavik is also of a fairly good 

 size and, though empty, appears rather "fresh". 



Distribution. Cardium groenlandicum is a high-arctic and circumpolar species; its southern 

 boundary lies in the Atlantic at Cape Cod (Dall) and Varanger Fjord (G. O. Sars) 1 ) and Porsanger 

 Fjord (Friele), in the Pacific at Hakodade and Puget Sound (Dall). 



Remarks. However well-characterized this species may be against all the other northern 

 Cardiida, it nevertheless shows a series of variations. 



This is especially evident in quite young specimens. In regard to sculpture some are radially 

 furrowed only on the posterior area, the majority likewise on the anterior area, some even over the 

 whole shell. Some are quite flat, others greatly ventricose and transitions occur. Some are uniformly 

 coloured, whitish, straw-yellow, gray or brownish, others again have dashes of yellowish-red. 



Adult specimens vary especially in regard to form. Some are high, short and greatly ventricose, 

 others comparatively elongated and flat, as will appear from the accompanying measurements: 



.... T , Height Breadth 



Locality Length Height Breadth 



Length Length 



Berufjordr (Iceland) 90""". 77 ™. 85.6% 50""". 55-6% 



Jakobshavn (Greenland).. 85 - 71 - 83.5 - 50 - 58.8 - 



Djupivogr (Iceland) . . 75 59.5 - 79.3 - 35 . 46.7 - 



Tunugdliarfik (Greenland) 73.5- 57 - 77.6 - 34 - 46.3 - 



0nundarfj6rdr (Iceland).. 71 - 59.5 - 83.6 - 37 - 52.1 - 



Godhavn (Greenland) ... . 70 - 62 - 88.6 - 42 - 60 - 



'i At this place, however, only small specimens have been taken, according to Sars I.e. 



