ADDENDA. 359 



7. S. clarkii, Rich. MISSOURI TROUT. COLUMBIA 

 RIVER TROUT. Head somewhat carinate. All streams 

 from Rio Grande and Basin of Utah to Upper Missouri 

 and Northwestward to the Pacific. 



Var. clarkii. Scales 155 165. Streams of Oregon 

 and Washington, chiefly W. of Cascade Range. (/$. 

 stellafus, Grd., S. bremcauda and S. gibbsii, Suckley.) 



Var. aurora, (Grd.) Scales 165 175. Streams chiefly 

 E. of the Cascade Range. (S. lewisi & S. virginalis, 

 Grd., S. carinatus, Cope.) 



3. CRISTIVOMER, Gill & Jordan. GREAT LAKE TROUTS. 



1. C. namaycush, (Walb.) G. & J. MACKINAW TROUT. 

 GREAT LAKE TROUT. LONGE TOGUE. (See text). Scales in 

 170 215 rows. Lakes, from Rocky Mountains to Maine, 

 and northward. Individuals from Eastern Lakes vary 

 somewhat, but can hardly be specifically distinct. Their 

 scales average rather larger, the colors are often darker, 

 and the gray spots sometimes tinged with red. (S. con- 

 finis, DeKay, S. symmetrica, Prescott, S. toma, Hamlin, 



S. adarondacus, Norris.) 



2. C. siscowet, (Ag.) G. & J. SISCOWET. Differs 

 from the preceding in the great fatness of the flesh, and 

 in having all the bones of the head shortened and broad- 

 ened; scales in 175 180 rows. Lake Superior. 



4. SALVELINUS, Richardson. CHARRS. 

 (Umbla, Rapp. Baione, DeKay. Salmo, Siebold.) 



* Hyoid bone with a median band of teeth. 



a. Body elongate, slender, compressed; head quite small, 

 with mouth smaller than in any other of our trouts, the 

 maxillary not reaching to posterior margin of eye ; cau- 

 dal well forked ; adipose fin small ; red spots small, con- 

 fined to the sides of the body. 



