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University of California Publications in Zoology [Vol. 21 



Distrihutdon. — Occurs in sequestered spots (about permanent 

 springs) in the valley of the Amargosa "River," which leads into 

 Death Valley, Inyo County, California; altitude of occurrence so far 

 as now known, 1500 to 1600 feet ; life zone, Lower Sonoran. Material 

 at hand, 12 skins-with-skulls, from the type locality, as above. 



Comparisons. — Aniargosae differs from Thamomys perpallidus 

 aureus Allen, as determined from examination of a topotype series of 

 this race in the collection of the United States Biological Survey, from 



TABLE I. 



Measurements, in millimeters, of eleven adult specimens of Thoviomys perpallidus 

 amargosae, all collected by T. I. Storer at Shoshone, Inyo County, 



California, May 9 to 14, 1917 g 



Bluff, San Juan County, Utah, as follows: Coloration not strongly 

 ochraceous-tawny or "golden buff'," but a very different, yellowish 

 gray ; dark patch around ear more extensive ; lower surface not white, 

 but pale buffy, with more of basal lead-color showing through ; skull 

 squarer, not so narrow as in aureus; zygomatic arches more widely 

 spreading and strongly angled ; rostrum broader ; bullae not so evenly 

 rounded. 



As compared with topotypes of T. p. perpes Merriam from the 

 vicinity of Lone Pine, Inyo County, California, as represented numer- 

 ously in the Museum of Vertebrate Zoology, amargosae shows paler, less 

 tawny, dorsal coloration ; the dark aural patches are much more exten- 

 sive ; the general size is greater ; the skull is much heavier and broader, 

 the zygomata more squarely spreading, the bullae more inflated, and 

 the incisors decidedly more forward-projecting. (See figs. 2, 3.) 



