252 Canadian Record of Science. 



the " breadth " or, as it would now be called, the length 

 of which is stated to be 3.9 inches. The recent receipt 

 from Mr. Simpson of outline drawings of specimens from 

 Dr. Lea's collections, labelled " A. decora, from the canal 

 at Cincinnati, Ohio," has, however, convinced the writer 

 of the correctness of Mr. Simpson's determination, though 

 it is very generally believed that A. decora is not more 

 than a mere variety of A. grand is. 



Anodonta edentula, Say. (A. undulata, Lea, et auct., but 

 possibly not of Say; A. Pennsyhanica, Lamark, and 

 A. areolata, Swainson.) 



Dr. R Ellsworth Call has expressed the opinion that A. 

 edentida, Say, is peculiar to the Mississippi drainage sys- 

 tem, and A. undulata,, Say., to those waters that drain 

 into the Atlantic, but the writer has never been able to 

 see any tangible difference between these two shells. In 

 a recent letter to the writer, Mr. Simpson says, " Anodonta 

 undulata is no doubt the small form which we have here 

 in the Potomac. Though Say gives no locality, he speaks 

 of it as 'thin and fragile, length near half an inch; breadth 

 seven-tenths.' The figure fairly well represents our shell. 

 This may run into A. edentida, but I have never yet been 

 able to connect it with that. The material in Lea's collec- 

 tion, under the name of A. undulata, Say, is merely a 

 form or forms of A. edentida!' 



Under one or the other of these names this shell has 

 previously been recorded as having been collected in Lake 

 Matapedia, P.Q., by Dr. K. Bell in 1857 ; in a small lake 

 in the valley of the Eiviere Eouge, P.Q., by W. S. M. 

 D'Urban, in 1858 ; in the St. Charles Biver, near Quebec 

 city, by the writer, in 1861, and at Brome Lake, P.Q., by 

 Mr. K. J. Fowler, in 1862. 



More recently, it has been collected by Dr. E. Bell in 

 1883, at Lake Winnipeg, between Ports Alexander and 

 Simpson, and by Professor Macoun, in 1894, in Ontario,. 



