52 U.S. NATIONAL MUSEUM BULLETIN 282 



A^. gyrinus funnels northward through the lowlands into much of the 

 northern Ohio and upper Mississippi Valleys, and into the Missouri 

 system, where it occurs throughout northern Missouri. It reaches a 

 westward limit in eastern Kansas, Nebraska, and South Dakota. 

 A^. gyrinus is distributed in the Hudson Bay drainage from the Red 

 River of the North in the Dakotas at least to Black Bear Island in 

 Lake Winnipeg, Manitoba (Keleher, 1953), and has been reported from 

 the Rainy River (Carlander, 1948; W. B. Scott, 1963) and the Souris 

 River, Saskatchewan (Symington, 1959). In the upper Great Lakes 

 basin, A^. gyrinus is known from the Saint Louis River system and 

 tributaries to western Lake Superior, from the Lake Michigan basin 

 in the Menominee River system, and occurs southward throughout 

 most of the Lake Michigan and Lake Huron drainages of the Lower 

 Peninsula of Michigan. It apparently avoids the northern part of the 

 Lower Peninsula. It occurs in the drainages of the lower Great Lakes 

 to Montreal, Canada, and has occupied the Mohawk and upper 

 Hudson River systems of New York. 



Elsewhere, A^. gyrinus has been introduced into the Merrimack 

 River of New Hampshire, into the Connecticut River system of 

 Massachusetts, and into the Snake River of Idaho and Oregon. 

 Probably there were many introductions of this species along with 

 bullheads (Ictalurus) into other bodies of water. Arnold and Ahl 

 (1936) indicated that A^^. gyrinus was once introduced as an aquarium 

 fish into Germany, but that it did not reproduce. 



Specimens of A'', nocturnus, N. insignis, N. flavus, and, probably 

 N. exilis have been reported as this species. 



Nomenclature. — Contrary to the opinion of Hubbs and Raney 

 (1944), I do not think that Hermann's (1804, p. 309) description of 

 Silurus mollis (reprinted in C. L. Hubbs, 1936, p. 125, and in Hubbs 

 and Raney, 1944, p. 25) can be shown to apply to this species. Hence, 

 their action in changing its name from Silurus gyrinis Mitchill is 

 regarded as invalid. The description is so incomplete that Silurus 

 mollis will probably forever remain a nomen dubium. Some information 

 bearing on the understanding of the description (Hermann, 1804, 

 p. 309) of Silurus mollis follows : 



1. "Observationes Zoologicae ..." was edited and published in 1804 

 after Hermann's death; thus the original description may not convey 

 the meaning intended by Hermann. 



2. This work has not been entirely overlooked. Several of the catalogs 

 of the British Museum cite it in their bibliographies, but they rarely 

 list or assign its new names. It may be that the descriptions are too 

 incomplete or indefinite to identify. 



3. Hermann was a member of the faculty of the University of Stras- 

 bourg. According to Dr. Francois Gouin (personal communication) 



