244 University of California Puhlicafions in Zoology. L^ol. 7 



series of nevadotsis in the ^luseum collection. The ratio of the 

 zygomatic width to the length (see table of measurements) is the 

 same in the four as in desert orum; while the ratio of the height 

 of cranium at bullae to length of skull is two per cent, greater 

 in the four than in desertorum. This was adduced as character- 

 istic of nevadcnsis in the original description. The other ratio, 

 namely that of squamosal width to length, departs from this rule, 

 and is greater than the series of desertorum (Taylor, 1910, p. 

 295), and very appreciably greater than in our series of 

 nevadensis. 



No differences are apparent between incisors of the Deep 

 Hole and Granite Creek specimens, and desertorum. The molars 

 are brown as in a majority of specimens of nevadensis. (How- 

 ever, Allen, 1894, p. 243, has shown that this character is not 

 reliable as a species characteristic.) 



In order to determine whether the statement given for 

 nevadensis (Taylor, 1910, p. 293), concerning the rostrum, 

 namely "rostrum in nevadensis relatively longer and more nar- 

 row than in desertorum," would hold for the four skulls in ques- 

 tion, I took the following measurements. 



Comparative Eostral and Cranial Measurements op Four Skulls op 



nevadensis prom Deep Hole and Granite Creek, 



Washoe County, Nevada. 



All dimensions are in millimeters. 



Actual length Ratio rostrum to 



of rostrum* Total lengthf total length 



78283 13.7 39.9 34.3 



78284 14.0 40.6 34.5 

 78289 13.7 38.5 35.6 

 78287 14.0 38.8 36.1 

 Average 13.85 39.45 35.12 



Similar Measurements op desertorum prom the Mohave Desert. 



Calipornia. 



All dimensions are in millimeters. 



5370 

 5374 

 5384 

 5383 

 6968 

 Avoragn 



* Measured from anterior end of nasal bones to most postrrior ]ioinf on 

 notch in dorsal anterior root of zygomatic arch. 



t Total k-ngth := length of cranium, from posterior bulge of brain-case 

 to most anterior part of premaxillary. 



