270 CALIFORNIA MAMMALS. 



tion is at its height about the end of March, at which time they 

 are very abundant about certain springs along the western border 

 of the Colorado Desert, appearing early in the evening, some- 

 times soon after sunset. By the middle of April they are much 

 less abundant al^nut these springs. Their flight is swift and erra- 

 tic and they are hard to shoot. They probably hide in crevices in 

 rocks on hillsides during the daytime. I found twO' foetuses in a 

 female shot May i8th. 



Genus Eptesicus RafinesquE. (House flier.) 

 Sktdl large and heavily built; size rather large; ears rather 

 short and narrow; tragus rather short, narrow, pointed; wing and 

 tail membranes naked ; wings large. 



Dental formula, I, 2 — 3; C, i — 1 ; P, i — 2; M, 3 — 3'X2^32. 



Eptesicus fuscus bernardinus Rhoads. (Brown; of San 



Bernardino. ) 



SAN BERNAR'DINO BAT. 



Above wood brown or Isabella brown; below paler; skull 

 flat; rostrum very broad. 



Length about no mm. (4.33 inches); tail vertebrae 46 

 (1.80) ; ear from crown 14 (.55) ; expanse of wings 330 (13). 



Type locality, San Bernardino, California. 



Southern California, principally in the mountains. Rathei 

 common in summer in the pine region. 



Eptesicus fuscus melanopterus Rehx. (Black — wing.) 



SIERRA BAT. 



Similar to bcniardiims but darker; abo^-e dark cinnamon; be- 

 low reddish wood bro^\n ; face and membranes black. 



Type locality, Mt. Tallac, Sierra Nevada, California. 



The range of the Sierra Bats has not been worked out, but it 

 is probably all the forested region of central and northern Call- 



