It is noteworthy that the upland fishes are nearly the same in all these streams until we reach the southern limit of possible glacial influence. South of western North Carolina the faunæ of the different river basins appear to be more distinct from one another. Certain ripple-loving types are represented by closely related but unquestionably different species in each river basin, and it would appear that a thorough mingling of the upland species in these rivers has never taken place. The best examples of this are the following: In the Santee basin are found _Notropis pyrrhomelas_, _Notropis niveus_, and _Notropis chloristius_; in the Altamaha, _Notropis xænurus_ and _Notropis callisemus_; in the Chattahoochee, _Notropis hypselopterus_ and _Notropis eurystomus_; in the Alabama, _Notropis coeruleus_, _Notropis trichroistius_, and _Notropis callistius_. In the Alabama, Escambia, Pearl, and numerous other rivers is found _Notropis cercostigma_. This species descends to the sea in the cool streams of the pine woods. Its range is wider than that of the others, and in the rivers of Texas it reappears in the form of a scarcely distinct variety, _Notropis venustus_. In the Tennessee and Cumberland, and in the rivers of the Ozark range, is _Notropis galacturus_; and in the upper Arkansas _Notropis camurus_,--all distinct species of the same general type. Northward, in all the streams from the Potomac to the Oswego, and westward to the Des Moines and the Arkansas, occurs a single species of this type, _Notropis whipplei_, varying eastward into _Notropis analostanus_. But this species is not known from any of the streams inhabited by any of the other species mentioned, although very likely it is the parent stock of them all.