No. 4.] DAWSON — POST-PLIOCENE. 389 



This species is fossil at Uddevalla, and is supposed to be the 

 same with C.fallax and C. obliquatus of Wood from the English 

 Crag. It has not yet been recognized on the American coast. 

 (See Figure.) 



Margarita helicina, Fabricius. 



Fossil — Montreal ; Murray Bay. 



Young specimens resemble M. acuminata of Mighels. Broad 

 Specimens resemble 31. campanulata, Morse. 



Recent — x\rctic seas ; Gulf of St. Lawrence ; and coast of New 

 England. It is M. Arctica, Leach. 



Margarita argentata, Gould. 



Fossil — Montreal, rare. 



Recent — Labrador and Gulf St. Lawrence (Whiteaves) ; Mur- 

 ray Bay ; Gaspe ; coast of New England and Nova Scotia ? 

 Possibly the same with M. glauca, Moll., from Greenland. 



Margarita cinerea, Couthuoy. 



Fossil — Riviere-du-Loup, Portland. 



Recent — Gasp^ ; Labrador ; Greenland to New England ; var« 

 striata, Dall, Sitka. 



Cyclostrema, (^3fdlle?'ia^ costulata, Moller. 



Fossil — Montreal; Clyde beds; Uddevalla. 

 Recent — Gasp^ ; Arctic seas to New England. 



Cyclostrema Cutleriaiia, Clark. 



Fossil — Montreal, rare. 



This is an Arctic and British shell, as yet recognized only at 

 Montreal. 



Turritella erosa, Couthuoy. 



Fossil — Labrador; Rivicre-du-Loup ; Montreal? • 



Recent — Greenland to New England. 



Turritella, reticulata, Mighels. 



Fossil — Labrador (Packard). 



Recent — Labrador to Gulf St. Lawrence ; also fishing banks, 

 Nova Scotia (Willis). 



My specimens received from Dr. Packard are marked T. costu- 

 lata, but seem rather to be the above species. 



