NATURAL SCIENCES OF PHILADELPHIA. 97 



On the Marine Shells brought by Mr. Drexler from Hudson's Bay, and on the 

 occurrence of a Pleistocene deposit on the Southern shore of James' Bay. 



BY WM. STIMPSON. 



Mr. Drexler, who last summer visited the south-eastern shores of Hudson's 

 Bay, under the auspices of the Smithsonian Institution, has brought home some 

 shells which it will be of interest to notice here, siuce nothing has been hitherto 

 published upon the molluscous fauna of that region. The physical conditions 

 of the bay do not seem to be favorable to any great development of true marine 

 mollusks at the present day, though we have evidence of an abundance of deep- 

 sea species at a former epoch. The waters of the bay are now mostly shallow 

 and somewhat brackish. 



Cape Hope, the point at which the marine shells were collected, is situated 

 on the eastern side of James' Bay, in latitude about 52 10' N. Only three spe- 

 cies of these shells were found alive, but these occurred in great numbers, 

 above low water mark. They were 

 Mytilus edulis L. 



Macoma fragilis 0. Fabr. (T. gro'nlandica.) 

 Littorina gro'nlandica Chemn. 

 The Littorina reaches a large s:ze, (0-65 inch,) and is probably identical with 

 L. tenebrosa. We cannot distinguish it from specimens from Greenland. 



The following species were found dead at Cape Hope, perhaps washed out of 

 some pleistocene deposit, as they are the characteristic species of that period. 

 Rhynchondla psittacca Ch. 

 Pecten islandicus Mull. 

 Cardium islandicum Ch. 

 Astarle arctica (Gray.) 

 Astarte striata (Leach.) 

 Mi/a truncala Lin. 

 Admete viridula (0. Fabr.) 

 The specimens of Cardium were much eroded on the outer surface, leaving 

 sharp, distant, crenulated, concentric ridges, as in those from the pleistocene ol 

 Lake Cuamplain. 



The southern part of James' Bay is so shallow that even small boats must go 

 out.of sight of land to find water deep enough to enable tbem to float at low 

 tide. This part, called Hannah Bay, forms the embouchure of the Hannah river, 

 in which Mr. Drexler collected many fresh water shells, chiefly elongated 

 Lymnece, and large Planorbes. In a box of these shells we found a considerable 

 number of marine species,, evidently fossils washed out of the river banks, 

 indicating the existence there of an extensive marine pleistocene deposit. The 

 following is a list of the species, which, with one exception, are deep water 

 forms. 



Mytilus edulis Lin. 

 Nucula ixpansa Reeve (iV. tenuis.) 

 Yoldia portlandica (Hitch.) 

 Leda permda (Mull.) 



Macoma sabulosa (Spengl.) (T. proximo.) 

 Of these, the Yoldia portlandica was most abundant, about twenty specimens 

 being found, with valves united, among which there were forms exactly cor- 

 responding to Y. siliqua Reeve, which appears to be only a vaiiety. This spe- 

 cies is now found living in the Arctic seas, where it was dredged by Capt. Sir 

 Edward Belcher. We may here remark that we have met with living examples 

 of Astarte, exactly corresponding to A. laurentiaiia, so that none of the borea! 

 pleistocene species yet found in North America can be regarded as extinct. 



1861.] 



