210 K. R. MII.I.KR 



one-time abundance, presumably through competition with intro- 

 duced fishes. Sculpins are common (5 species of Cottus and 1 of 

 Leptocottus) , but suckers are not numerous; minnows have developed 

 5 endemic genera (in part, perhaps relicts). The fish fauna shows 

 affinities with each of the surrounding basins, the Columbia (Ptycho- 

 cheilus, Siphateles) , the Great Basin {Gila, Siphateles), the Klamath 

 {Cottus), and the Colorado {Ptychocheilus). High endemism (75 

 per cent) at the species level indicates rather long and effective 

 isolation for much of the basin. The likely mode of penetration of 

 Great Basin types was indicated by Robins and Miller (1957, pp. 

 229-230). 



Klamath River 



Studies of the geology and ichthyology of this drainage indicate 

 that the part above Klamath Falls has only recently established an 

 outflow to the Pacific by the headward erosion of Klamath River; 

 certain elements of the fauna largely or entirely restricted to the 

 lakes and streams above the Falls strongly suggest former connec- 

 tions with the Great Basin (Hubbs and Miller, 1948, pp. 67-68; 

 Robins and Miller, loc. cit.). Nine genera and 13 species occur above 

 the Falls, and of these, 8 species {Entosphenus tridentatiis, Salmo 

 clarki, S. gairdneri, Catostomus snyderi, Gila bicolor, Rhinichthys 

 osculus, and Siphateles bicolor) have also been reported from below 

 (Snyder, 1908). Catostomus snyderi and Gila bicolor are known from 

 single records only but Siphateles bicolor was taken at 3 localities by 

 Snyder (1908, p. 159, as Rutilus bicolor). On distributional grounds 

 it is clear that these three species were originally present only in the 

 upper part of the Klamath basin and gained access to the remainder 

 of the river by being carried downstream over the Falls. It is likely 





Fig. 19. Klamath Lake sculpin, Cottus princeps, a vicarious fresh- 

 water fish restricted to Upper Klamath Lake, Oregon. (From original 

 drawing by Anna L. Brown; see Gilbert, 1898, p. 12.) 



