6 
BULLETIN OF THE UNITED STATES FISH COMMISSION, 
More destructive, however, are the chubs {Leuciscus). Of these, none ascend to 
the mountains in the Arkansas or the Platte. But, in the Rio Grande, one species, 
Leuciscus pulcher, exists in abundance, while in the Colorado, the Round-Tail {Gilaro- 
busta) is equally common. Another chub-like fish in the Colorado, Ftyclioclieilus lucius, 
reaches a great size, the largest of all tlie Cyprinidcc, and in default of better fish, as- 
sumes economic importance. 
Other minnows ascend the Arkansas and Platte, though only to the foot of the 
mountains. Most of these are of species common in the Mississippi Valley. The 
bulk of the rich fauua of the Mississippi is however excluded from Colorado, because 
the species can not ascend the turbid waters of the lower Arkansas or Platte. 
The darters, sunfishes, and catfishes can hardly be said to belong to Colorado, 
as nearly all the species are shut out by the unfit character of the lower streams. 
These were seen by us only about Denver and Pueblo. In a similar way most of the 
Texan fishes are excluded from the Rio Graude. 
INTRODUCED PISHES. 
The Eastern brook trout {Salvelinus fontinalis) has been introduced into numerous 
streams (Bear Creek, Twin Lakes, Echo Lake in Egeria Park, Ruxton Creek, To- 
michi Creek, etc.). It does well everywhere, aud is said to grow more rapidly than the 
native trout, but this statement is denied by some partisans of the latter fish. 
The rainbow trout of California ( /iSabHo iridetis) has been sparingly introduced, 
and is reported to do well. One specimen was obtained by us in Twin Lakes. 
The land-locked salmon of Maine {Salmo salar sebayo) has been introduced into 
Twin Lakes, where specimens are occasionally taken. 
A number of carp ponds also exist in the State. 
As an addition to the above list, I would strongly recommend the introduction of 
the larger catfishes, especially Leptops oUvaris, Ictalurus punctahis, ?ind Ameinrtis neb- 
ulosus, into the tributaries of the lower Colorado, as the Green River and the San 
Juan. Pood is abundant, aud every couditiou seems to be favorable for them, while 
the whole great basin of the Colorado contains, excepting the trout, no fish of even 
second-rate character as food for man. 
A.— THE PLATTE BASIN. 
The South Platte rises in the elevated iilateau known as the South Park. Through 
the park it flows in an undulating course over grassy fields, finally breaking through 
the mountains to the sage plains above Denver. It receives many tributaries from 
the mountains, and the waters of numerous sandy runs, dry in summer, pour in from the 
plains. Its water, both above and below Denver, is largely used for irrigation. Thus 
it becomes a shallow, muddy stream, with sandy bottom and very low banks. In the 
northeastern part of Colorado it meets its fellow, the North Platte, a stream of similar 
character, rising in the North Park. The Platte, now a broad, very shallow stream, 
full of sandbars and quicksands, flows eastward across Nebraska to the Missouri. 
The fishes of the Platte, as far up as Denver, are mostly the ordinary species of the 
upper Missouri region. The trout do not descend below the level of the parks, and 
are scarce even in the South Park itself, being chiefly confined to the mountain gorges 
above it. 
