26 



liJ-ORTH AMEEICAK FAUNA. 



[No. 36. 



shorter rostrum than the two adults taken by Gary at Medano Ranch, 

 thus closely agreeing with specimens of R. a. griseus from Texas. 

 The rostrum of this specimen is deflected markedly to the right, 

 indicating an injury during life, which may account for its small 

 size and peculiar characters. The original description of the color 

 accords perfectly with the series now in hand, so that there seems 

 no alternative but to consider the type skull aberrant, and to con- 

 tinue to use the name for the form represented by the modern series. 



The species, although combining in a remarkable degree the char- 

 acters of the megalotis and albescens groups, seems not to be directly 

 connected with either of them. It is perhaps best placed in the 

 megalotis group, but seems not to intergrade with any member of it.^ 



Though but little smaller than R. m. megalotis, it is markedly 

 smaller than aztecus — the form ranging through northern New Mexico, 

 nearest to the home of montanus. It may be distinguished from both 

 megalotis and aztecus by smaller size, particularly of the ears and tail, 

 and by paler and less ochraceous coloration. Externally it much 

 resembles R. a. albescens but is somewhat darker and has larger ears 

 and feet. The nearest approach geographically of R. albescens griseus 

 to the range of montanus is at Santa Rosa, N. Mex., and the single 

 specimen taken there shows no departure from typical griseus. 



Specimens examined. — Total number, 21, from the following locali- 

 ties: 



Colorado: Del Norte, 1; Medano Ranch (15 miles northeast of Mosca), 20. 



REITHRODONTOMYS MEGALOTIS MEGALOTIS (Baird). 

 Desert Harvest Mouse. 

 ■ (PI. I, fig. 6; PI. IV, fig. 6; PI. VII, figs. 1, 7.) 

 Reithrodon megalotis Baird, Mamm. N. Am., 1857, p. 451. 



Reithrodontomys megalotis Allen, Bull. Am. Mus. Nat. Hist., V, 1893, p. 79; VII, 

 1895, p. 125. 



Reithrodontomys megalotis deserti Allen, Bull. Am. Mus. Nat. Hist., VII, 1895, p. 127 

 (Oasis Valley, Nev.). 



Reithrodontomys megalotis sestinensis Allen, Bull. Am. Mus. Nat. Hist,, XIX, 1903, 

 p. 602 (Rio Sestin, northwestern Durango). 



Type locality. — Between Janos, Chihuahua, and San Luis Springs, 

 N. Mex. 



Distribution, — From northern Nevada and southern Idaho south 

 to Zacatecas, Mexico ; occupying the greater part of Nevada, Arizona, 

 and Utah (except eastern part) ; southern New Mexico ; western Texas 

 (west of Pecos Eiver) ; desert regions of southern and northeastern 

 California, northeastern Lower Cahfornia, and northern Sonora; 

 and northern portion of Mexican table-land. 



1 Gary's assignment of this species to the albescens group (N. Am. Famia No. 33,1911, p. 108) was on the 

 authority of the present writer, who, after more detailed study, has reached the conclusions set forthabove. 



