160 The Trouts of America 



in some waters, be confused with the rainbow. 

 Hence, the following detailed description of 

 structure and coloration of the Shasta is re- 

 quired : 



The body is nearly four times its depth, and the 

 head is of the same proportion to the length of the 

 body; in the first dorsal and anal fins will be 

 found eleven rays, and the tail fin is more deeply 

 forked than in the cut-throat, while the steelhead 

 has a truncate or nearly square tail fin ; the scales 

 are larger than in the other two species named, 

 and the eye is larger than in the steelhead, the 

 mouth moderate in size. The coloration is bluish 

 on the back and silvery on the sides, and all over 

 the head, fins, and body above the median line 

 black spots appear, the belly being nearly free 

 from them. (The cut-throat has but few spots on 

 the head, with deep red fins, and the steelhead is 

 olive-green on the back and has no red on the 

 lower jaw.) The fins seldom show a red tinge, 

 but there is always present in both sexes of the 

 Shasta trout the broad red lateral band and 

 blotches, and to render identification more difficult 

 and confusing there is usually a dash of red on 

 the under jaw, similar to that shown under the 

 mandible of the cut-throat, which, unfortunately 



