Colorado Trout 223 



the mountain streams of the state, ranging in 

 habitat southward as far as the mountains of 

 Chihuahua in Mexico. Its physical characteris- 

 tics are pronounced: the body is four times 

 longer than its depth ; the head three and a 

 half times shorter than the length of the body 

 and it is heavy but short, the upper surface 

 being considerably concaved or decurved ; it has 

 a large mouth, the upper jaw reaching backward 

 beyond the eye, and the teeth on the roof of the 

 mouth are in two series. The first dorsal fin is 

 short in front, and the rear rays are long and 

 high, the last being nearly two-thirds the height 

 of the first one ; similar proportions exist in the 

 anal fin, the last ray being longer than the 

 others. This fish has numerous round spots on 

 the back, sides, and on the tail and fatty fins ; on 

 the body they are more profuse on or near the 

 fleshy part of the tail (peduncle). It grows to a 

 length of about thirty inches and is apparently 

 identical with the Colorado River trout (Salmo 

 clarkii pleuriticus). It differs, however, from 

 that fish in that the scales are less crowded on 

 the anterior part of the body and are longer. 

 Its technical subspecific name is derived from 

 two Greek words signifying " spotted tail." 



