354 University of California Publications in Zoology [Vol. 10 



List and Measurements in millimeters op full-grown females of 

 Thomomys nigricans ' 



Mus. 



Locality 

 Hemet Lake, San Jacinto Mts. 

 Hemet Lake, San Jacinto Mts. 

 Hemet Lake, San Jacinto Mts. 

 Hemet Lake, San Jacinto Mts. 

 Hemet Lake, San Jacinto Mts. 

 Strawberry Valley, San Jacinto Mts. 

 Strawberry Valley, San Jacinto Mts. 

 Strawberry Valley, San Jacinto Mts. 

 Strawberry Valley, San Jacinto Mts. 

 Strawberry Valley, San Jacinto Mts. 

 Strawberry Valley, San Jacinto Mts. 

 Thomas Mt., San Jacinto Mts. 

 Schain's Ranch, San Jacinto Mts. 

 Schain 's Ranch, San Jacinto Mts. 

 Schain's Ranch, San Jacinto Mts. 

 Average of the 15 J? 



Thomomys altivallis Rhoads 

 San Bernardino Mountain Gopher 



The twelve specimens of gophers referred by us to this species 

 were obtained at but two localities: Tahquitz Valley, 8000 feet, 

 ten (nos. 2188-2197), and Round Valley, 9000 feet, two (nos. 

 1761, 1762). The latter is well within the Boreal zone and the 

 former is at least high Transition. As no other gopher was 

 obtained above low Transition, it is evident that altivallis is the 

 Boreal representative of the genus on this mountain as it is on 

 the San Bernardino range (see Grinnell, 1908, p. 150). Not 

 one old male was secured on San Jacinto ; but five females, as 

 shown in the accompanying table, measure close to the average 

 of San Bernardino Mountain females. In coloration both adults 

 and young are identical with corresponding pelages in the San 

 Bernardino series, save that there is more or less white on the 

 throat and belly of several of the San Jacinto skins. 



If our identification proves correct, Thomomys altivallis so 

 far as now known exists only on the San Bernardino and San 

 Jacinto mountains, with the deep San Gorgonio Pass separating 

 these two colonies. Small differences may yet be found as a 



