414 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



idan specimens the head has scarcely any spots ; in the other, the head is well 

 spotted; there is also a marked difference in the size of the spots, those on 

 the Idaho specimens being much the larger. Contrasting these differences in 

 tabular form we have the following : 



These differences are very marked, and would certainly be of sufficient 

 importance to justify the specific separation of the two if found to hold good 

 throughout the range of each. But various more or less intermediate char- 

 acters are shown in specimens from other localities, and it is probably best, 

 for the present at least, to regard these forms as subspecies of typical mykiss; 

 in which case the form found throughout the upper Missouri Basin and in the 

 Snake River above Shoshone Falls will stand as Salvw mykiss letvisi (Girard), 

 and the common form of the Snake River basin below Shoshone Falls, as 

 Salmo mykiss gibbsii (Snckley). The eastern limit in Wyoming in the range 

 of the black-speckled trout is only approximately known. We know that 

 trout are abundant in Yellowstone Lake 1 and in the streams in and about 

 the park, from which they are not barred by waterfalls ; they are also in 

 the Yellowstone River and its upper tributaries. It is undoubtedly in the 

 Clark Fork of the Yellowstone and Big Horn River, though no specimens 

 have been received from those streams. We know it is an abundant fish in 

 the Tongue River basin, and it is probably found in the headwaters of Pow- 

 der River, though we have no definite record of the fact. It is not found in 

 any of the streams in or about the Black Hills, as we have already stated in 

 this paper. At present the most eastern point from which specimens have 

 been obtained, of which we have definite record, is Sheridan, Wyo., from 

 south fork of Tongue River, and Big Goose Creek. Further investigations 

 in Wyoming are very much to be desired, especially in the region drained 

 by the Clark Fork of the Yellowstone, the Big Horn, Powder River, the 

 North Platte, and the Sweetwater. 

 93. Salmo mykiss stomias (Cope). Platte Eiver Trout. Kansas River near Fort 

 Riley, 2 Kans. (as Trutta lewisi,Cope, 1865); Platte [Kansas] River near Fort 

 Riley, Kans. (as Salmo {Salar) stomias type, Cope, 1871); Platte [Kansas] 

 River (in part as S, pleuritieus type, Cope, 1872) ; Bear Creek, Morrison, Colo. 

 (Jordan, 1891). 



)In Ludlow's Report of a Reconnaissance from Carroll, Mont. Ter., on the Upper Missouri, to the 

 Yellowstone National Park and return, made in the summer of 1875 (War Dept., 1876), we find the 

 following interesting note (p. 20) concerning the trout of this lako : " There seem to be two varieties 

 of trout here, the bulky ones of the Yellowstone, with bright yellow bellies and stripings of red, and 

 a smaller kind, more silvery in appearance and exhibiting much greater activity and game qualities. 

 These latter seemed to come generally from the [Tower] creek." 



2 Locality probably erroneous. The specimens more likely came from some point near the head- 

 waters of the South Platte, where variety stomias is found. 



