Recent Canadian TJnionidai. 251 



Lamarck and others, will ultimately have to be retained 

 for some of these shells. 



ANODONTA, Lamarck, 1879. 

 Anodonta Benedictii, Lea. 



Specimens which appear to have been identified with 

 this species by Dr. Lea have already been recorded by 

 Dr. K. Bell 1 as having been collected by himself, in 1860, 

 at Batch-ah-wah-nah Bay, Lake Superior ; in the St. Mary 

 Biver, near Sugar Island, and on the north shore of Lake 

 Huron, at Lacloche Island. Professor Macoun has 

 recently (1894) collected it at Eondeau, near Point aux 

 Pins, on the Ontario side of Lake Erie, and a few speci- 

 mens, which Mr. Simpson thinks are probably referable 

 to A. Benedictii, were collected by Dr. E. Bell, in 1883, at 

 Lake Winnipeg, between Fort Alexander and Elk Island. 

 Mr. Simpson is inclined to believe that A. Benedictii may 

 be only a variety of A. ovata, Lea. 



Anodonta decora, Lea. 



Eight full grown specimens and one immature shell of 

 a very large Anodonta, which Mr. Simpson refers to A. 

 decora, were collected by Mr. Law, of Chatham, at Eon- 

 deau, Ontario, and presented by him to the Museum 

 of the Survey, through Professor Macoun, in 1884. One 

 of the adult shells from this locality, a fairly average 

 specimen, measures 6.6 inches in length, 4 inches in- 

 height and 3.1 inches in breadth or thickness. The 

 umbones of each are remarkably ventricose and pro- 

 minent. The test is rather thick, the hinge line short, 

 and the cardinal angles are rounded in front and obtusely 

 angular behind. The writer has long been under the 

 impression that these shells could be identified with the 

 typical form of A. grandis, Say, as they do not correspond 

 at all well with Lea's figures or measurements of A. decora, 



i In Canad. Nat. and Geol., Vol. VI., p. 269. 



