MAMMALS OF THE MBXICAIir BOUNDARY. 



879 



under surface, feet, and end of tail, white. Average measurements of 

 two adult females: Length, 1.54 mm.; tail vertebree, 56.5; ear from 

 crown, 15; lengthof hind foot, 21.3. Skull (fig. 66), 26.3 by 13.5. 



A young male (No. 60815, U.S.N.M.), about two -thirds grown, 

 taken at Seven Wells, on the Colorado Desert, in Lower Califoruia, 

 measured 128 mm. in length, with the tail vertebrae 50, ear from 

 crown 14, and hind foot 21. Above, it is smoke gray. The ear shows 

 a distinct dusky spot of mouse gray, and the terminal third of the tail 

 is all white. 



Measurements of 5 specimens Onychomys torridus perpallidus. 



a Contained 4 large fetuses. 



> Type. 



ONYCHOMYS TORRIDUS RAMONA (Rhoads). 

 RAMONA GRASSHOPPER MOVSE. 



Onychomys ramona Rhoads, American Naturalist, XXVII, p. 833, Sept., 1893 (original 



description). — ^Miller and Rehn, Proc. Bost. Soc. Nat. Hist., XXX, No. 1, Dec. 



27, 1901, p. 67 (Syst. Results Study N. Am. Mam. to close of 1900). 

 [Onychomys'] ramona, Elliot, Field Col. Mus., Zool. Ser., II, 1901, p. 121 (Synop. 



Mam. N. Am.). 

 0[nyehomys] ramona, Elliot, Field Col. Mus., Zool. Ser., IV, 1904, pp. 165, 167 (Mam. 



Mid. Am.). 



Description. — Size of typical Onychomys torridus but very much 

 darker in color. Proportions about the same as those of torridus. 

 Upper surface drab, tinged with cinnamon on sides, and much mixed 

 with black on top of head and vertebral area; lanuginous tufts at base 

 of ear soiled grayish white; ears blackish, edged with white apically; 

 upper side of tail blackish nearly to the tip; whiskers mostly black; 

 under surface, feet, and extreme tip of tail, white. Average measure- 

 ments of two adults, male and female: Length, 143 mm.; tail verte- 

 brae, 51.5; ear above crown, 14; length of hind foot, 20.5. Skull, 25 

 by 13. 



Two gray-pelaged young, collected bj'' Mr. Holzner, May 21 and 25, 

 at the foot of the Santee Mountains, San Diego County, California, 

 have the upper surface mouse gray, and the ears nearly black. They 

 are the darkest specimens seen of this species. 



