_Salmo henshawi_, the trout of Lake Tahoe and its tributaries and outlet, Truckee River, found in fact also in the Humboldt and the Carson and throughout the basin of the former glacial lake called Lake Lahontan. This is a distinct species from _Salmo clarkii_ and must be regarded as the finest of all the cutthroat-trout. It is readily known by its spotted belly, the black spots being evenly scattered over the whole surface of the body, above and below. This is an excellent game-fish, and from Lake Tahoe and Pyramid Lake it is brought in large numbers to the markets of San Francisco. In the depths of Lake Tahoe, which is the finest mountain lake of the Sierra Nevada, occurs a very large variety which spawns in the lake, _Salmo henshawi tahoensis_. This reaches a weight of twenty-eight pounds. [Illustration: FIG. 66.—Tahoe Trout, _Salmo henshawi_ Gill & Jordan. Lake Tahoe, California. ] In the Great Basin of Utah is found a fine trout, very close to the ordinary cutthroat of the Columbia, from which it is derived. This is known as _Salmo clarkii virginalis_. In Utah Lake it reaches a large size. In Waha Lake in Washington, a lake without outlet, is found a small trout with peculiar markings called _Salmo clarkii bouvieri_. In the head-waters of the Platte and Arkansas rivers is the small green-back trout, green or brown, with red throat-patch and large black spots. This is _Salmo clarkii stomias_, and it is especially fine in St. Vrain's River and the streams of Estes Park. In Twin Lakes, a pair of glacial lakes tributary of the Arkansas near Leadville, is found _Salmo clarkii macdonaldi_, the yellow-finned trout, a large and very handsome species living in deep water, and with the fins golden yellow. This approaches the Colorado trout, _Salmo clarkii pleuriticus_, and it may be derived from the latter, although it occurs in the same waters as the very different green-back trout, or _Salmo clarkii stomias_. [Illustration: FIG. 67.—Green-back Trout, _Salmo stomias_ Cope. Arkansas River, Leadville, Colo. ] [Illustration: 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. [Illustration: FIG. 69.—Rio Grande Trout, _Salmo clarkii spilurus_ Cope. Del Norte, Colo. ] [Illustration: FIG. 70.—Colorado River Trout, _Salmo clarkii pleuriticus_ Cope. Trapper's Lake, Colo. ]