316 



All the East-Greenland specimens belong to the variety 

 with the angular somewhat expanded shape: expansa Reeve; 

 they obtain a length of up to I5"5 mm. 



Leda permda Müller. 



1901—02. Tasiusak. . .30— 50 fms. 1 specimen. 



1900. Cape Dalton... 9 — 11 — Clay with small stones 12 — and 1 valve. 



1900. Turner-Sound . . . ca. 3 — 6 — 



1891—92. Hekla-Havn . 3—6 — б — 



1900. Hurry-Inlet -50 — Clay with stones 17 - and 3 valves. 



1900. Forsblad-Fjord ..14—3 — 1 — 



1900. SE.of Sabine-Island 110 — Fine clay with stones 



and gravel 1 — 



In 1883 the Nordenskiöld-Expedition took 5 specimens 

 off Angmagsalik at 25 — 40 fms.; it was moreover taken by the 

 Ко 1th off- Expedition in 1900 in Mackenzie-Bay, N. of Franz 

 Joseph-Fjord, on muddy ground and at depths from 6V2 — 19 fms. 

 (14 specimens) and 53 fms. (1 specimen) (Hägg 1. с. p. 8). 



Along East-Greenland Leda pernula has thus been found 

 to occur on the line from Tasiusak to Sabine-Island, or from 

 ca. 65V2— 74V2° N. 



All the specimens found at East-Greenland belong to the 

 variety costigera Beck. The periostracum is on the whole light 

 and straw-coloured. The concentric striation is fine (sometimes 

 however more distinct). In larger specimens the periostracum 

 is frequently wanting on a great part of the shell and the 

 underlying lime highly eroded; apart from this the shell is in 

 itself rather thin; the longitudinal rib on the inside of the po- 

 sterior end is well developed. 



The species obtains a considerable size at East-Greenland. 

 From Turner-Sound we have one specimen of 26 mm., from 

 Cape Dalton several of 27 — 32 mm. and from Hurry-Inlet some 

 of 30—34 mm. 



Fossil. The East-Greenland Expedition of 1900 found 

 a fragment of a valve at Hurry-Inlet, opposite the anchoring 

 place. 



