1921] Grinnell: Two New Rodents from Eastern California 



241 



Amargosae differs from T. p. mohavensis Grinnell (1918, p. 427) 

 of the southern portion of the Mohave Desert as to color rather more 

 slightly than from other members of the group ; but the peculiar yel- 

 lowish tone mentioned in the diagnosis, rather than bright cinnamon- 

 buff, is a fairly constant feature. Greater size of skull, heavier rostrum, 

 and more squarely spreading zygomata are additionally distinctive. 



From its very near neighbor, T. scapterus Elliot, on the Panamint 

 Mountains, adjacent to Death Valley, amargosae is markedly different 



Fig.l 



Fig. 2 



Fig. 3 



Fig. 1. Thomomys scapterus Elliot, topotype; male, no. 26449; Hanaupah 

 Canon, Panamint Mountains, Inyo County, California; May 14, 1917. 



Fig. 2. Thomomys perpaUidus perpes Merriam, topotype; male, no. 16844; 

 Lone Pine Creek, near Lone Pine, Inyo County, California; April 12, 1912. 



Fig. 3. Thomomys perpaUidus amargosae, new subspecies, type; male, no. 

 26485; Shoshone, Inyo County, California; May 14, 1917. 



All natural size. 



in its much greater size, paler coloration, and more massive skull ; the 

 rostrum is much heavier, the nasals are far longer (some 30 per cent) ; 

 and the bullae are fully double the volume that they are in scapterus. 

 (Seefigs. 1, 3.) 



As compared with 2\ operarius Merriam, of the immediate environs 

 of Owens Lake, amargosae is slightly paler of color, with larger aural 

 dusky spot; the general size is decidedly larger; rostrum of skull 

 longer and not so broad, with incisors longer and more projecting; 

 bullae much larger. 



