FISHES, LAHONTAN SYSTEM OF NEVADA AND NORTHEASTERN CALIFORNIA. 35 



Walker Lake is a rival of Pyramid Lake in scenic beauty, lying in a long narrow 

 valley with towering mountains on either side and the desert sloping down to the water's 

 edge. It is comparatively fresh near the inlet, but grows more saline toward the lower 

 end, where no fishes except carp are said to go. Walker River is its only tributary. 



In addition to the larger basins here described there are several creeks which are 

 isolated. One or two of these north of Black Rock Desert are said to contain fishes. 



The streams of the entire system are much alike in that they have their origins in 

 the mountains and are often fed by melting snow. Their upper courses are cool, clear, 

 and pure; but on reaching the valleys the currents slacken, the water at length becoming 

 warmer and often silted and alkaline. They are all subject to great changes in volume," 

 gradually or even suddenly becoming raging torrents and again decreasing in size until 

 in some cases their currents fail and their waters are dissipated through evaporation 

 or lost in the thirsty sands. Of late years nmch water has been used in irrigation, 

 the entire flow of some streams being thus diverted for considerable periods. Unusually 

 high water has lately occurred in some of the lakes, as the dead pines at Eagle Lake 

 and submerged fences at the head of Wiimemucca Lake plainly indicate. Pyramid 

 Lake was somewhat higher in 1911 than when seen by Russell,* as a comparison of his 

 view of the tufa castle on the west shore of Pyramid Lake (Russell, pi. xl), and the 

 photograph here presented (pi. iv, b) will show. 



The insular position of the Lahontan system has been noted. On the east is the 

 Bonneville, a similar system of interior drainage; on the north the Columbia, including 

 Snake River; while on the west and south are the Klamath, Sacramento, San Joaquin, 

 and Colorado systems. On the northwest, between the Lahontan and the Klamath and 

 bordering the Columbia and Sacramento, is another region of interior drainage, the 

 Oregon Lake system, a portion of the Great Basin to which reference will again be made. 



DISTRIBUTION AND RELATIONSHIPS OF SPECIES. 



Fifteen native species of fishes are now recognized in the Lahontan system. They 

 are enumerated below and accompanied by page references to the "Fishes of North and 

 Middle America,"" where an index to the literature pertaining to the various species 

 may be found. 



Catostomidee. 



Catostomus iahoensis Gill and Jordan; C. tahoensis, p. 177. 



C arenarius, new species. 



PantosUus lahontan Rutter. 



Chasmistes cujus Cope; C. cujus, p. 183. 

 Cyprinidse. 



Richardsonius egregius {Gvczid); Letteiscus egregiiis, p. 2iy. 



R. microdon, new species. 



Siphateles obesus (Girard); Rutilus olivaceus, p. 244; R. symmetricus, p. 245. 



Leucidius pectinifer, new species. 



Agosia robusta Rutter; A. nubila carringtonii, p. 311. 



» United States Geological Survey, Water Supply and Irrigation Papers, nos. 68. 133, 134, 176, 313, jjo, 350, and 351. 



*» Department Interior, Monograph Geological Survey, vol. XI, 1885. 



^ Jordan and Evermann, Bulletin 47, United States National Museum, Washington. 



