1898-1902. No. 20.1 BKACHIOPODS AND MOLLUSCS. 



Very common ; at the last-named dredging station nearly 600 speci- 

 mens were obtained. 



The specimens, which have a length of up to 23 mm. belong partly 

 to the variety portlandia, HITCHCOCK and partly to the variety siliqua, 

 REEVE. The majority helong to intermediate forms. I append some 

 measurements of specimens which were taken at the same time at the 

 head of the Gaasefjord : 



Long. 23 mm. Lat. 13.5 mm. Crass. 10.2 mm. 



99 c 1 q (\ e 



<n.& ,. lo y.o n 



22.2 12.7 8.7 



22 13 10.5 



21.5 12.2 7.7 



21.5 12.5 .. 9.5 



21 12.5 8 



20.7 12.5 , 9 



20.5 13 9 



20 ., 11.5 ., 8 ,. 



19.5 .. 12 7,5 



111 12.5 .. 8.5 .. 



18 ., ' 12.2 8 



17 10.5 ., 6.5 



Thus in these specimens the height of the shell is 56.74 67.78 "/ 

 of the length and the breadth 35.3447.73 % of the length : in some 

 other specimens I have found moreover that the breadth of the shell 

 can be as much as 49.11 "/ of the length. 



Yoldia hyperborea, LOVEN. 



L o c-a 1 i t y : 



Aug. 18. 1898. Bay near Rice Strait. 



Sept. 19. 1900. Off Forvisningsdalen, Gaasefjord, 440 m. Clay with small stones. 



Sept. 20. The head of the Gaasefjord. 640 ra. Clay with small stones. 



Aug. 2. 1901. , about 40 m. 



The species seems to be very scarce, since not more than at most 

 3 specimens have been found at any locality. 



The specimens quite accord with specimens from Spitzbergen and 

 Novaya Zemlya in the Bergen Museum. The height of the shell varies 

 between 49.3 "/ and 55.9 % of the length, while its breath (thickness) 

 is between 25 / and 31 % of its length. In a specimen 31 mm. long 

 there were anteriorly 25 hinge-teeth and posteriorly 20 hinge-teeth. In 

 a specimen 25 mm. long the number of hinge-teeth were 24 and 20 



