Twin Lakes Trout 231 



River trout {pleuriticus) or descended from it. It 

 certainly possesses many physical characteristics 

 of that fish; the scales are about the same size, 

 and the fin rays nearly alike in number, but the 

 head and the gill covers are longer, and the two 

 fishes vary greatly in coloration, that of the yel- 

 low-fin being a light olive with a broad shade of 

 lemon-yellow along the sides, with no red on any 

 part of the body except the crimson slash on the 

 throat. On the posterior part of the body, and on 

 the dorsal and tail fins, there is a profusion of 

 small black dots giving the fish the appearance 

 of having been strewn with the contents of a 

 pepper castor ; on the head and anterior parts of 

 the body few or none of these spots are present. 

 This is a large, handsome fish, growing to a 

 weight of nine pounds (one specimen of thirteen 

 pounds has been reported), and is abundant in 

 Twin Lakes, Colorado, but is never found in 

 streams. It delights to bask in the sun on the 

 shallow gravel beds, and is seldom caught in the 

 deeper water. They feed largely upon the young 

 suckers which are numerous in the lake, and the 

 suckers in turn destroy large quantities of the. 

 spawn of the yellow-fins. The flesh of this trout 

 is paler than that in other forms and somewhat 



