No, 4.] DAWSON — POST-PLIOCENE. 375 



Panoj)cea Norvegica, Spengler. 



Fossil — Leda clay ; Riviere-du-Loup. Very rare. 



Recent — Dredged in Gasp^ Bay, 30 and 40 fathoms, by Mr. 

 Whiteaves ; Halifax (Willis) ; Grand Manan (Stimpson) ; 

 Arctic and northern seas generally. 



It is very rare in the Post-pliocene, a few valves only having 

 been found at Riviere-du-Loup. The specimens are small, and 

 much inferior to those found in the Scottish Clyde beds, of 

 which I have a specimen from Rev. H. Crosskey. 



My a truncata, Linn, (and var. Uddevallensis). 



Fossil — Saxicava sand and Leda clay ; Montreal ; Quebec ; 

 Riviere-du-Loup ; Portland ; New Brunswick (Matthew) ; La- 

 brador (Packard) ; Greenland (Moller) ; also in the Post-pliocene 

 of Europe. 



Recent — Gulf St. Lawrence, but rare in comparison with its 

 abundance in the drift. Generally distributed in the Arctic seas 

 and North Atlantic, American coast as far south as Cape Cod ; 

 Puget Sound (=preciosa, Gould, P. P. C.) 



The variety found in the Post-pliocene of Canada is the short 

 ov UddevaUensis YSLYieiy, which, is that occurring in the Arctic 

 seas at present, while in the Gulf St, Lawrence the ordinary long 

 variety is found almost exclusively. At Portland, Maine, how- 

 ever, the long variety lived in the Post-pliocene, and occasional 

 specimens are found at Riviere-du-Loup. The form Uddevall- 

 ensis occurs living in Labrador (Packard), and I have found it at 

 Tadousac. 



It is interesting to observe that while the present species is 

 more abundant than the next in the Post-pliocene, it is much 

 more rare in the Gulf at present. It also occurs in deeper water. 



My a arenaria, Linn. 



Fossil — Leda clay and lower part of Saxicava sand ; Montreal ; 

 Upton ; Quebec ; Murray Bay ; Labrador ; Duck cove and Law- 

 lor'slake, New Brunswick ; Portland, Maine; Greenland (Moller) ; 

 also in the Post-pliocene of Europe. 



Recent — Very abundant throughout the Gulf St. Lawrence 

 and coast of Nova Scotia and New England, also Arctic seas 

 generally. Mr. Jeffreys considers it identical with 31. Japonica, 

 Jay. Not found yet in W. America. (P. P. C.) 



In the Gulf this species grows to a large size ; I have a speci- 

 men five inches long from Gaspd ; but in the Post-pliocene it is 



