288 



Dispersion of Fresh-water Fishes 



more distinct; third, those of the creeks of the hill country; 

 fourth, those of the elevated mountain streams which are sub- 

 ject to falls and rapids." 



In the same paper Prof. Cope reaches two important general 

 conclusions, thus stated by him : 



"I. That species not generally distributed exist in waters 

 on different sides of the great water-shed. 



"II. That the distribution of the species is not governed 

 by the outlet of the rivers, streams having similar discharges 

 (Holston and Kanawha, Roanoke and Susquehanna) having 



Fig. 1S7. — Butterfly-sculpiii, Melletes papilio Bean, a fish of the rock-pools. 

 St. Paul, Pribilof Islands. 



less in common than others having different outlets (Kanawha, 

 or Susquehanna and James). 



"In view of the first proposition, and the question of the 

 origin of species, the possibility of an original or subsequent 

 mingling of the fresh waters suggests itself as more probable than 

 that of distinct origin in the different basins." 



Questions Raised by Cope. — Two questions in this connec- 

 tion are raised by Prof. Cope. The first question is this: "Has 

 any destruction of the river fauna; taken place since the first 

 elevation of the AUeghanies, when the same species were thrown 

 into waters flowing in opposite directions ? " Of such destruc- 

 tion by submergence or otherwise. Prof. Cope finds no evidence. 

 The second question is, "Has any means of communication 



