191^] TajjJor: MawrnaJs of ihe 1909 Nevada ExpediHon. 239 



Comparative Measurements of Other Species op Eeithrodontomys. 

 All dimensions are in millimeters. 



Average of 58 specimens 



B. m. megaloUs* 134.4 



Average of 128 specimens 



R. m. deserti* 136.1 



Average of 62 specimens 



B. m. longicauda* 137.1 



Average of 4 specimens 



B. klamatliensis^ 146.2 



* See Allen, 1895, p. 141, etc. 



t See C. H. Merriam, 1899, p. 93. 



No. 8190, male adult, taken at Quinn River Crossing on ]\Iay 

 18 may be regarded as typical of the series. Coloration of upper 

 parts buffy, darkened along the middle of the back by an in- 

 sprinkling of slate-black and cinnamon; general impression of 

 the upper parts more of a brownish than a blackish, differing in 

 this respect from Keith rodontomys of presumably contiguous 

 range, which have more black intermixed ; ears light brown ; ear- 

 tufts white with buffy endings ; whiskers vary, some being black, 

 others brown ; sides of animal pale, clearly distinguishable in this 

 regard from deserti as represented by the Victorville examples, 

 and from Mamathe nsis ; deserti has the sides ochraceous, or 

 even darker than ochraceous, instead of pale-buffy, and klama- 

 thensis has the sides similar to those of the Nevada specimens, 

 but darker. Feet white ; underparts silvery- white, all the hairs 

 except those on the throat having plumbeous bases; a line of 

 white present on the lower part of the cheeks and around the 

 mouth ; tail well-haired, seal brown above, white below. 



One is impressed at first sight by the larger size of these 

 specimens as compared with deserti from the Mohave Desert. 

 Actual measurements, however, show this greater size to be merely 

 apparent, and due to greater length and fluffiness of the pelage. 

 The length of the tail vertebrae of the animals from northern 

 Nevada is intermediate on the average (see table of external 



