1898-1902. No. 20.] BRACH10PODS AND MOLLUSCS. 19 



Thracia truncata has not been previously found in waters north 

 and west of Baffin Bay; though it should be stated that thracia obliqua 

 JEFFREYS, of which there is but one fossil valve from Grinnell Land, is 

 possibly merely a deformed form of this species, as indeed I am in- 

 clined to believe. 



Thracia septentrionalis, JEFFREYS. 



Locality: 



March 7. 1900. Bay south of Sj6p6lse Ness, Havnefjord, 3040 m. Small stones 

 slightly overgrown with laminaria. 



Two specimens measuring: 



Long. 20.5 mm. Lat. 14.5 mm. Crass. 7.5 mm. 



18.5 13.5 6.5 



The specimens are not so thick-valved and short as those taken 

 by "Voringen" near Jan Mayen. They more closely resemble in these 

 respects specimens from Norskoerne, Spitzbergen. 



Like the last-mentioned, thracia septentrionalis has not been pre- 

 viously found in the archipelago north af America. 



Pandora, kennerleyia, glacialis LEACH. 



Locality: 



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

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

 Aug. 2. 1901. , about 40 m. 



Aug. 16. , about 14 m. 



Of this species there are only six specimens, so that it seems to 

 be scarce. 



The largest specimen measures: Long. 25.7 mm., Lat. 15.2 mm., 

 Crass. 4.7 mm. In the smallest specimens these measurements are 

 respectively 17.5 mm., 10.5 mm., and 2.5 mm. The epidermis of the 

 right valve is marked with radiating lines, as may also be seen in the 

 drawing of LECHE; though in the specimens collected by the Fram 

 these are stronger and more distinct than they are in the drawing. 

 When the shell is closed the margin of the left valve bends downwards 

 over the right valve, while the margin of the latter bends upwards. 

 The same will be found to be the case with several other molluscs such 

 as pecten gronlandicus. When various authors assert that the margin 

 of the left valve of this species projects slightly over that of the right 

 valve, this is due in most cases to a strong contraction of the animal, 

 resulting in the margin of the valve becoming bente. 



