Fig. 67.—Green-back Trout, Salmo stomias Cope. Arkansas River, Leadville, Colo.
Fig. 68.—Yellow-fin Trout of Twin Lakes, Salmo macdonaldi Jordan & Evermann. Twin Lakes, Colo.
Two fine trout derived from Salmo clarkii have been lately discovered by Dr. Daniel G. Elliot in Lake Southerland, a mountain lake near Lake Crescent, but not connected with it, the two separated from the sea by high waterfalls. These have been described by Dr. Seth E. Meek as Salmo jordani, the "spotted trout" of Lake Southerland, and Salmo declivifrons, the "salmon-trout." These seem to be distinct forms or subspecies produced through isolation.
Fig. 69.—Rio Grande Trout, Salmo clarkii spilurus Cope. Del Norte, Colo.
Fig. 70.—Colorado River Trout, Salmo clarkii pleuriticus Cope. Trapper's Lake, Colo.
The Rio Grande trout (Salmo clarkii 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 ordinary cutthroat-trout, and the black spots are chiefly confined to the tail. Closely related to it is the trout of the Colorado Basin, Salmo clarkii pleuriticus, a large and handsome trout with very small scales, much sought by anglers in western Colorado, and abounding in all suitable streams throughout the Colorado Basin.
Hucho, the Huchen.—The genus Hucho has been framed for the Huchen or Rothfisch (Hucho hucho) of the Danube, a very large trout, 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 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. In northern Japan is a similar species, Hucho blackistoni, locally known as Ito, a large and handsome trout with very slender body, reaching a length of 2½ feet. It is well worthy of introduction into American and European waters.