74 SCIENCE SKETCHES. 



seems to promise a ready adaptation to other 

 surroundings. 



The Rio Grande Trout (Salmo mykiss spilurus) 

 is a large and profusely spotted trout, found in 

 the head-waters of the Rio Grande, the mountain 

 streams of the great basin of Utah, and as far 

 south as the northern part of Chihuahua. Its 

 scales are still smaller than those of the red- 

 throated trout, to which it bears much resem- 

 blance, and of which it is probably simply a local 

 variety. 



The genus Hucho has been framed for the Huchen 

 or Rothfisch (Hucho huchd] of the Danube, a large 

 salmon, differing from the genus Salmo in having 

 no teeth on the shaft of the vomer, and from the 

 Salvelini at least in form and coloration. The 

 real characters of the genus, which seems to be 

 distinct from Salvelinus, have not yet been- 

 worked out. The Huchen is a long and slender, 

 somewhat pike-like fish, with depressed snout and 

 strong teeth. The color is silvery, sprinkled with 

 small black dots. It reaches a size little inferior 

 to that of the salmon, and it is said to be an 

 excellent food-fish. Little is known of its habits. 

 It has, however, the reputation of being unusually 

 voracious for a salmon. 



The genus Salvelinus comprises the finest of the 

 Salmonidce, from the point of view of the angler 

 or the artist. In England the species are known 

 as charr, in contradistinction to the black-spotted 

 species of Salmo, which are called trout. The 

 former name has unfortunately been lost in Amer- 

 ica, where the name " trout" is given indiscrimi- 



