242 THE ICE AGE IN CANADA. 



This shell has been found as yet only at Riviere-du-Loup, where 

 the specimens however are as good as those now living in the Gulf. 

 It will be observed, however, that though they have the number 

 of teeth of Y. limatula, they approach in form to the allied species 

 or variety Y. sapotilla, a shell which occurs in Greenland and thence 

 to New England, and which I strongly suspect is merely a short 

 variety bearing a similar relation to Y. limatula to that which 

 Mya Uddevallensis bears to the ordinary M. truncata ; but Jeffreys 

 considers it distinct. Y. sapotilla is, I may mention, the Y. arctica of 

 Morch, as proved by a specimen from his collection now in my possession. 



Yoldia myalls. Couthuoy. 



Fossil — Labrador (Packard). 



Recent — Riviere-du-Loup ; Little Metis ; Kamouraska ; Gaspe 

 (Whiteaves) to south of Cape Cod. This shell is supposed to be 

 identical with hyperhorea^ Loven, from Spitzbergen. 



Leda fossa. Baird. 



Fossil — Vancouver Island (Dr. G. M. Dawson). 

 Pecten Groenlandicus. Chemnitz. 



Fossil — Leda clay, Portland and Saco, Maine ; not yet found in 

 Canada. 



Recent — Gulf St. Lawrence (Whiteaves), in deep water 200 to 300 

 fathoms. 



This species is found in the Clyde beds and in Greenland ; and if, as 

 Jeffreys supposes, identical with P. similis (Laskey), it is a shell of 

 very wide distribution in the Atlantic, as well as in geological time. 

 Though not yet found in Canada as a Pleistocene fossil, its occurrence 

 as a fossil in Maine and recent in the Gulf St. Lawrence, renders it 

 probable that it may yet occur in our Leda clays. 



Pecten tenuicostatus. Mighels. ( = P. Mogtllanicus. Lamarck. ) 



Fossil — Leda clay, St. John, N.B. (Matthew). 



Recent — Labrador to Cape Cod. 



This shell has not yet been found in the Pleistocene of the St. 

 Lawrence valley; but since, according to Packard, it is common in 

 Labrador, there is nothing remarkable in its occurrence at St. John. 



Pecten Islandicus. Chemnitz. 



Fossil — Riviere-du-Loup ; Quebec ; Anticosti ; Labrador (Packard) ; 

 St. John, N.B. (Matthew); Portland, Maine ; Greenland (Moller); also 

 Crag, Clyde beds, and Post-pliocene of Norway, 



