88 THE NAUTILUS. 



Genessee R., N, Y, Cohoes Falls, Hudson R. 



Ottawa, Can., Rideau Canal. Seneca Lake, N. Y. 



INIontreal, Can. Oneida Lake, N. Y. 



St. Lawrence R., Thousand Isles. Moose R., Hudson Bay. 



Camden, S. C. Lake Winnipeg. 



Oguchee R., Ga. Athabaska Lake. 



Savannah R. Great Slave Lake. 



Charles Co., Indiana ! Small Lakes, Mackenzie R. 



Red River of the North. 



New Mexico. 

 I have collected Unio luteolus in Eastern Colorado, and it is in 

 the General Collection of the National Museum from Mississippi 

 and Texas. It probably ranges from the Artie circle to the Gulf of 

 Mexico, and from the Rocky ^Mountains east to the Atlantic, except 

 in the southeastern states lying east of the Appalachian Chain. A 

 small form occurs in Canada and the more northern states, which is 

 quite solid, and has a dark, rather rough, brown epidermis, often 

 without rays, sometimes almost black, and in form and texture is 

 is strikingly like some specimens of U. Doioniei from Southern Ga., 

 but has not a lurid nacre as the latter has. This was named Unio 

 borealis by A. F. Gray, and differs sufficiently from the type to be 

 considered a distinct species, but it connects insensibly through 

 forms found in Wisconsin and Michigan with the western shells. 

 One of these in the collection of Dr. Lea (85045) from Montreal, 

 was referred by him to radiatus. Other forms of this protean spe- 

 cies are so close to ligamentinus that it is almost impossible to sepa- 

 rate them and this is true of ce"rtain specimens o^ radiatus. 



ON THE USE OF THE GENERIC NAME SCUTELLINA. 



BY 11. A. riLSBRY. 



The name ScutelUna was proposed by Gray in 1847, to replace 

 Scutella of Broderip, preoccupied by Lamarck for a genus of Echi- 

 noderms. It has aj^parently escaped the attention of malacologists 

 who have written upon this small but excessively interesting group, 

 that Agassiz, in 1841, used the name ScutelUna for a genus of Echi- 

 noderms allied to Scutella Lam. This generic term is still in use, 

 appearing in the latest publications relating to that group. It 



