1870.] CANADIAN FOSSIL OSTRACODA. 385 



EXTRACT FROM NOTES ON FOSSIL OSTRACODA 

 FROM THE POST-TERTIARY DEPOSITS OF 

 CANADA AND NEW ENGLAND. 



By George Stewardson Brady, C.M.Z.S., and H. W. Crosskej F.G.S. 

 (^Froiii the Geological Ma grizlne for Feh.^ 1871.) 



We are indebted for the material from which the following 

 notes have been compiled to Principal Dawson of Montreal, and 

 to the Secretary of the Portland Society of Natural History, to 

 whom our best thanks are due for the opportunity thus afforded 

 us of comparing the fossils of the North American Clay Beds with 

 those of our own country. By carefully washing the clays kindly 

 forwarded to us, we have obtained many specimens in excellent 

 condition for examination. 



Of the thirty-three species here noticed, twenty-three are well 

 known to us as occurring in the Scottish Glacial Clays, twenty-five 

 are living inhabitants of the British Seas, while six {Cytliere 

 cuspidata, C. MacChesneyi, C. Logani, Ci/therura granulosa, C. 

 cristata, Cytheropteron complanatuin) are new to science, being 

 here for the first time described. 



We know too little of the recent American Ostracoda to 

 institute any very precise comparison between them and the fossil 

 fauna represented by the following Hst of species ; but when com- 

 pared with British collections, we find the contents of the Canadian 

 fossiliferous clays to resemble very closely those of some similar 

 formations in Scotland, and less closely those of dredgings obtained 

 in the seas around the Hebrides and Shetland, 



The character of the Mollusca with which the Ostracoda are 

 associated justifies the same observation. About two- thirds of 

 the Mollusca collected from the Scotch glacial clays are also found 

 in the corresponding beds of Canada ; and the difference between 

 the glacial fossil fauna of Canada and that now existing in the 

 Gulf of St. Lawrence is far less marked than the difference 

 between the glacial fauna of the Clyde beds and that now existing 

 in the Firth. The fossil fauna of Canada is slightly more arctic 

 than that of the Gulf, but does not contrast with it so broadly as 

 the fauna of the Scotch glacial clays with the Mollusca still living 



