270 CALIFORNIA MAMMALS. 



tion is at its lieight 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 about 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 Rafinesoue:. (House flier.) 

 Skull 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, 1—2; I\I, 3—3X2=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 

 commoii in summer in the pine region. 



Eptesicus fuscus melanopterus Rehn. (Black — wing.) 



SIERRA BAT. 



Similar to bcniardiiius but darker ; above dark cinnamon ; be- 

 low reddish wood brown ; 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 Cali- 



