382 University of California Publications in Zoology [Vol. 10 



to be of this species were seen at almost every station, so that 

 taking into account the localities of fair certainty together with 

 those of actual capture, a greater zonal and faunal range is 

 indicated for Eptrsicus than for any other bat of the region. 



The specimens taken show much variation in color, and the 

 remarks made in regard to a series from the San Bernardino 

 Mountains apply here (see Grinned, 1908, p. 159). 



Pipistrellus hesperus hesperus (H. Allen) 

 Western Bat 



Eleven specimens were preserved as follows: vicinity of Dos 

 Palmos Spring. 3000 to 3500 feet, May 28 and August 25, six 

 (nos. 1895-1897, 1918, 1919, 9373); Palm Canon, June 13 and 

 16, three (nos. 9370-9372) ; Cabezon, 1700 feet, May 7, one (no. 

 1307); Banning, 2100 feet, June 9, one (no. 1462). There is 

 also in the Museum a skin (no. 6938) taken at Palm Springs, 450 

 feet, December 29, 1903; this was shot at dusk as it flew overhead 

 above a patch of mesquites. Several were seen in flight at early 

 dusk in the same locality, February 9 and 13, 1912. The occur- 

 rence of the species abroad in midwinter is of interest, as we have 

 no evidence otherwise as to whether or not the species is migra- 

 tory. 



This small bat was identified with certainty only on the desert 

 side of the San Jacinto Mountains, and. as shown above, appeared 

 to be restricted to the Lower Sonoran zone. Very many appeared 

 at early dusk along Palm Canon and in the neighborhood of Dos 

 Palmos Spring, where they were seen to emerge from crevices 

 of rocks. This was the only species of bat seen abroad after 

 sunrise and before sunset; in fact one individual was seen in 

 flight about 9 a.m. in the bright glare of the forenoon sun. 



