Recent Canadian TJnionidaz. 263 



Unio triangularis, Barnes. (?=» TJ. triqtceter, Eafinesque.) 



Collected by Professor Macoun, in 1885, at Port Col- 

 borne, Ontario, and in 1894, at Kondeau and in the 

 Thames Eiver at Chatham. 



Unio trigonus, Lea. (?= TJ. undatus, Barnes.) 



Port Dover, Lake Erie, Professor Macoun, 1890, two 

 perfect but worn specimens, which were identified with 

 this species by Mr. Simpson. 



Unio undulatus, Barnes. (?= TJ. costatus, Eafinesque.) 



Ontario. Sable Eiver, at Thedford, Mr. Bissell, 1883, 

 per Dr. H. Ami. Grand Eiver, Caledonia, J. Townsend, 

 1885. Lake Erie, at Port Colborne, and Detroit Eiver, 

 at Windsor, Professor Macoun, 1885. Grand Eiver, at 

 Cayuga, Professor Macoun, 1890, and Thames Eiver, at 

 Chatham, Professor Macoun, 1894. 



Manitoba. Black Eiver, Lake Winnipeg, Dr. E. Bell, 

 1883, two specimens, with the umbonal regions much 

 eroded. Emerson, Professor J. Fowler, one specimen of a 

 small form which approaches TJ. plicatus (Le Sueur, MS.S.) 

 Say. 



Unio ventricosus, Barnes. ( TJ. occidens, Lea, female, and 

 TJ. subovatus, Lea, male: ?= TJ. cardium, Eafinesque.) 



Common in the St. Lawrence and Ottawa rivers and 

 throughout Ontario. In Manitoba it has been collected 

 in the Eed and Eoseau Eivers by Dr. G. M. Dawson, in 

 1873, and at Lake Winnipeg, between Fort Alexander and 

 Elk Island, by Dr. E. Bell, in 1883. 



Ottawa, November 30th, 1894. 



