LAMELLIBRANCIIIATA. 



83 



Faxafjordr,ca.2 miles N.E. of Keflavik ig 1 2 — 20 1 2 fm., ooze. is valves. 



, 1 mile E. N. E. of Helgasker 



Vager 11' 2 . , spec . 



,4.3 miles W. \ 4 S. of Helga- 

 sker Vager 25 - 5 va lv< 



,E. of Videy g— 10 - , fine sand and ooze. 1 spec. 6c 1 valve. 



,ca. V', miles N. W. l i t N. of 



Engey Baake ig - , shells and stones. 1 



Reykjavik. 3 valves. 



— , Engey 7- 8 'A - , ooze. 1 spec. & 2 valves. 



Hafnarfjordr 25 - , fine black sand and ooze. 1 — & 20 



From the so nth-west coast (region of Faxafjordr) only separated valves or dead (empty 1 

 specimens are represented, though they often appear quite "fresh", with well-preserved ligament and 

 periostraeum ; the maximum length is only 53"". Hvalfjordr is however an exception from what has 

 just been said, as living specimens have been taken there, the largest of which is 14" long; a much 

 larger, but dead specimen appears quite "fresh" and the largest of the separated valves is 6] . lon°\ 

 On the north-west coast the species thrives well and reaches a length of 7 



-> mm 



3 



I Faeroes. I 

 A valve has been taken south-west of Sydero (6i°c/ N. L., 7'54'W. L.) at a depth of 180 fin., but 

 it is quite small (3.75 """.) and looks ancient (fossil). The species does not live at the islands. 



Distribution. Cardium ciliatum is a high-aretic and circumpolar species, as it occurs, apart 

 from West and East Greenland and northern Iceland, at Spitzbergen, in the Barents Sea, at Nova 

 Zembla and in the Kara Sea, in the Polar Sea of Siberia, Bering .Sea, at .Sitka and in the Wellington 

 Channel; the southern boundary for its distribution lies at Cape Cod (Da 11), East Finmarken iSars 

 and Friele), northern Japan and Puget Sound (Dall). 



Remarks. The shape of this species varies a good deal, as will he seen from the accompanying 

 measurements of 4 specimens from Iceland: 



Height Breadth 



Length Height Breadth 



Length Length 



73 """• 6 7 • 9i-8 °L 48 • »5-> s 



72 - 71 - gS.6 - 40 • 55.6 - 



71 - 64 - go.i - 42.5- 



65 - 58 - 89.2 - 33 50.8 - 



The very small specimens (see PI. Ill, fig. 10) can only be recognized as belonging to this 



species on comparing them witli somewhat larger specimens because the dorsal margin forms an angle 



with the anterior margin. The young thus obtain some resemblance to those of C.cchinatum (cf. p. 73 



and PI. Ill, fig. 11), but are easily distinguished by the fact, that the radiating ribs are more numerous, 



1 1 * 



