326 Umiversity of California Publications in Zoology  [Vou.17 
Skull—As described for the genus. May always be distinguished 
from that of Nycteris cinerea, by its decidedly smaller size (pl. 23, 
fig. 51, and pl. 24, fig. 59). The average skull length of the examples 
of cinerea in the Museum of Vertebrate Zoology is 17.5 millimeters, 
while that of the series of teliotis is but 12.5 millimeters. 
Measurements.—Average and extreme measurements in milli- 
meters of a series of 11 specimens in the Museum of Vertebrate 
Zoology are as follows: Total length, 104.5 (extremes, 98.0-111.0) ; 
tail vertebrae, 50.5 (42.0-60.0); tibia, 18.5 (17.0-19.7); foot, 8.5 
(6.0-11.0) ; forearm, 38.7 (34.0-41.3) ; greatest length of skull, 12.5 
(12.0-13.1). 
Synonymy and History—This bat was described by H. Allen 
(1891, pp. 5-7) under the name Atalapha teliotis. The description was 
based on a poor specimen without data, but presumably taken in 
southern California. This type is now number 84555, in the United 
States National Museum (Lyon and Osgood, 1909, p. 277). 
Distribution—The general range of Nycteris borealis teliotis is 
given by Miller (1912, p. 64) as follows: ‘‘From the head of Sacra- 
mento Valley, California, south to Comondu, Lower California.’’ 
J. Grinnell (19130, p. 280) gives the California range in winter and 
spring as Sacramento and San Joaquin valleys, from Sutter County 
southwards, and throughout the San Diegan district. (See map, 
text-fig. R.) A study of the dates of capture of California red bats 
leads the present writer to infer that the sexes separate during the 
summer months, the females remaining in the Lower Sonoran zone, 
while the males migrate into the Upper Sonoran and Transition zones. 
Among certain species of birds the males withdraw from the 
breeding grounds in early summer and forage elsewhere, often at 
higher elevations. Their departure relieves congestion in the nesting 
area and leaves a greater food-supply for the females and young. 
A study of the summer distribution of red bats in California leads 
one to believe that a similar habit exists among these vertebrates 
also. Of the red bats listed, with dates of capture, in the accompany- 
ing table, the nineteen adult females taken between April 15 and 
August 1 are all recorded from the Lower Sonoran zone; whereas 
of the four adult males taken during the same time of the year 
three are from the Transition zone and the fourth from the Upper 
Sonoran. All winter records of red bats, of both sexes, are from the 
two Sonoran zones. : 
Specimens Examined.—The writer has examined 56 examples of 
this bat from California. Since the seasonal movements of the Cali- 
fornia red bat have not been fully worked out, it seems pertinent to 
