34 THE OREGON SPORTSMAN 



either species, especially breeding males, the head is dispropor- 

 tionately large. 



SHAPE OF THE TAIL. 



In all under-size trout the tail is much more deeply indented 

 than in mature, large specimens. All big Rainbows I have seen 

 show a "square" or nearly right line along the margin of the tail 

 when fairly extended. This is so noticeable a feature that in many 

 places this trout is commonly called "square-tailed trout." 



Certainly the shape of the Rainbow's tail distinguishes him 

 easily from Clark trout, which has a rounded hollow in the 

 mid-margin, and the corners or lobes gracefully rounded. In the 

 Rainbow the points are sharply angular, as in the Steelhead. The 

 difference between the tails of all the salmon is easily learned, 

 but is so little as to confuse Steelhead and Rainbow. 



HEAD, MOUTH AND EYE. 



One of the characteristics given by Doctor Jordan is: "Head 

 obtusely ridged above." Several other writers copy this descrip- 

 tion exactly. It is plain that they have taken the Doctor's state- 

 ment without question, permission or examination. Look for the 

 "obtuse ridge," and see if there's any such feature. 



Doctor Jordan says, "the mouth is smaller than in Cut- 

 throat," and so it is. This difference is evident. The gape of the 

 Rainbow from tip of jaw to corner of the mouth is about one-fourth 

 less than in Cutthroat. The angle of the open mouth in Rainbow 

 is just in line with front edge of eye-pupil. In Cutthroat the 

 mouth extends back to middle of pupil or farther. 



In young and medium size fish the Rainbow's head is dis- 

 tinctly more blunt and rounded than in any other of our trouts. 

 In this feature there is a noticeable difference ffom the adult 

 Steelhead, which has a more pointed upper jaw. 



Comparison, I believe, will establish this difference as one 

 certain mark of recognition. There is an "innocent" air in the 

 profile of the Rainbow, due to this roundness of the front of the 

 maxillary. 



The eye seems to be a very notable point too. In recent 

 examinations I have observed the eye of Rainbows to be peculiar 



