18 JAMES A. GRIEG. [SEC. ARCT. EXP. FRAM 



both specimens with thick and thin valves may occur. Typical speci- 

 mens of the form arctica have a length of 25 26 mm., and a height 

 of 12.5 14 mm. Some specimens which may be referred to this form 

 have moreover a length of up to 38 mm., and a height of 16.5 mm. 

 The form pholaclis s. rugosa has a length of 46 47 mm., and a height 

 of 24 25 mm. 



Lyonsia arenosa, MOLLER. 



Locality: 



July 25. 1900. The winter harbour, Havnefjord, about 20 m. Rocks and stones. 



July 26. West side of the entrance to Stordalen, Havnefjord, 1620 m. Clay. 



Sept. 19. Off Forvisningsdalen, Gaasefjord. 440 m. Clay with small stones. 



Sept. 20. The head of the Gaasetjord. 6 40 m. Clay with small stones. 



Aug. 2. 1901. , about 40 in. 



Aug. 16. , about 14 m. 



In Havnefjord only a quite young specimen was obtained 7.5 mm. 

 long. In Gaasefjord 10 specimens in all were collected, which were 

 15-26 mm. long. The height of their shells varied from 54% to 

 64.25 o of their length, while the breadth (thickness) varied between 

 37.14 % and 42 ll / of their length. For purposes of comparison we 

 may state that JENSEN found in the case of some specimens from the 

 east coast of Greenland, that the height of the shell was 51.662.7 % 

 of the length and the breadth 36.944.7 /o of the length. Some of 

 the specimens from Gaasefjord measure: 



Long. 26 mm. Lat. 16.7 mm. Grass. 10.5 mm. 

 26 15.5 10 



25 15.5 ., 10.5 



25 13.5 9.5 



23.5 , 14.5 9 



18 10.5 7.5 



14.5 10 6.5 



15 9.5 6 



The specimens closely resemble the description and illustration which 

 HANCOCK gives of lyonsia gibbosa (lyonsia arenosa var. sibirica LECHE) 

 from Davis Strait. 



Thracia truncata, TURTON. 



Locality: 

 July 29. 1899. The winter harbour, Havnefjord, 12 m. A somewhat deformed 



specimen (Long. 18.5 mm., Lat. 14.5 mm., Crass 9 mm.). 

 July 25. 1900. The winter harbour, Havnefjord, about 20 m. Rocks and stones. 



One specimen (Long. 13 mm., Lat. 10 mm., Crass 7 mm.) belongs 



to the typical form, the other on the contrary more closely 



resembles the variety devexa G. 0. SARS. 



