IN THE ALLEGHENY REGION OF SOUTH-WESTERN VIRGINIA. 245 



rivers. These are of the genera Salmo, Poecilichtliys, Rhiniclithjs, CUnostomus and 

 Exoglossum, which seek the highest streamlets. This is especially the case with the 

 Bliinichihyes, which are particularly numerous above foils of eighteen and twenty feet. 

 There is also Uranidea, the species of which abound in the cold waters of the great 

 springs which burst from subterranean courses in many places in this region. I 

 never saw them in the subterranean portions of such waters, though I have had but 

 few such streams to examine. These species I have enumerated in Class IV. 



It appears to the writer that the occurrence of species not universally distributed, 

 in the heads of these adjacent but distinct basins, may be best accounted for in this 

 manner, after an examination of the ground. No attempt is made to account for the 

 distribution of the seven cosmopolite species in this way. 



Prop. II, that the fish fauna of rivers of the same geographical district have but a 

 slight relation to their points of discharge, may be further illustrated by comparing 

 the faunae of two adjacent tributaries of flie Kanawha, Strouble's and Sinking Creeks. 

 Their mouths are fifteen miles apart. 



One species, RhinicJdhys lunatus Cope, was found very abundant in both ; if any- 

 thing, Semotilus corporalis Mich, and Exoglossum maxiUingua Hald. were more 

 common in Strouble's Creek. Of these two the Exoglossum was very rare, and the 

 Semotilus absent, in Sinking Creek. The most common species of the latter were 

 Phoiogenis leucops and P. scabriceps Cope, neither found in Strouble's Creek. No 

 Hypsilepis or Ceratichthys in Strouble's Creek, neither uncommon in Sinking Creek ; 

 the same may be said of Uranidea and Hyostoma Agass. Species of Gampostoma, 

 nyhorhynclius, Gaiostomiis and Poecilichthys abounded in both. Individuals were 

 equally abundant in the two streams, which flow alike through limestone valleys. 

 They differ in important particulars, however; Sinking Creek, as its name indicates, 

 is not permanent throughout its course, sinking every summer for three miles from 

 its mouth. Strouble's Creek is permanent, and passes for part of its course through 

 the coal region of Price's Mountain, thus receiving streams containing copperas, etc., 

 in solution, and carrying down coal dust, which experience has shown to be very 

 fatal to fishes. 



In the case of Bear Creek, a tributary of the middle fork of the Holston, there were 

 taken nine species, of which five were not found, after much examination, in the 

 streams of the north fork. These wei'e SemotUiis corporalis, Hyhopsis lacerfosiis, H. 

 rubricroceus, H. speclruuculios, and Ghrosomus erythrogaster. And in another branch 

 of the middle fork, twenty miles below, all the north fork species were found, and but 

 one or two individuals of one species of the five of Bear Creek, i. e., Hyhopsis spectrun- 

 cidus Cope. At the time I visited these streams the last mentioned was strong and 

 full, while Bear Creek was reduced to a chain of pools. The difference of fauna is no 

 doubt connected with this fact. 



