260 Canadian Record of Scie?ice-. 



in the St. Lawrence and Ottawa rivers, has recently been 

 collected by Professor Macoun in Lake Erie, at Port 

 Colborne, in the Grand Eiver at Cayuga, and its two 

 branches at Gait and Ayr, also in the Detroit Eiver, at 

 Windsor. 



Unio gracilis, Barnes. (?= U. fragilis, Rafinesque.) 



Collected by Professor Macoun, in 1885, from Lake 

 Erie, at Port Colborne, and the Grand River, at Cayuga; 

 in 1890, at Port Dover, Ontario, and in 1894, in the River 

 Thames, at Chatham. 



Unio lachrymosus, Lea. (Probably = U. quadrulus, Ra- 

 finesque.) 



In Ontario, Professor Macoun collected specimens of 

 this species in the Grand River at Cayuga, in 1885, and in 

 the Thames River, at Chatham, in 1894. 



In Manitoba it was found to be abundant in the Red 

 River, by Dr. G. M. Dawson, in 1873, and Professor J. 

 Fowler has presented to the museum of the Survey a 

 specimen, which he collected at Emerson in 1887. 



Unio ligamentous, Lamarck. 



Grand River, at Caledonia, Ontario, J. Townsend, 1885, 

 and at Cayuga, Professor Macoun, 1890. Thames River, 

 at Chatham, Professor Macoun, 1894. Roseau River, 

 Manitoba, Dr. G. M. Dawson, 1873, and Assiniboine 

 River, at Millwood, J. B. Tyrrell, 1888. 



Unio luteolus, Lamarck. 



Common almost everywhere in Canada east of the 

 Rocky Mountains, though its exact range east of Ontario 

 is a little uncertain, owing to its close resemblance to 

 U. radiatus. Dr. Lea, in 1862, records it as occurring in 

 Great Slave Lake, Lake Athabasca, and near the mouth 

 of Moose River, Hudson's Bay. In Manitoba it was col- 

 lected by Mr. J. B. Tyrrell, in 1887, from the Swan River; 



