332 University of California Publications in Zoology  {|Vou.17 
Wing membranes nearest chaetura black, except area on dorsal 
surface directly above furred portion of ventral surface, which is 
light cinnamon brown; specklings of this color extend out onto the 
darker portions of membranes. 
According to Miller (1897), p. 113) the color variation, although 
considerable, is never enough to obscure the characters of the species 
and appears to be wholly independent of locality, certain skins from 
such widely separated regions as Minnesota and southern California 
being practically indistinguishable. 
Skull—sSimilar to that of Nycteris borealis teliotis but larger 
(pl. 28, fig. 49, and pl. 24, fig. 57). In N. b. teliotis the skull length 
varies from 12 to 13.1 millimeters, while in N. cinerea it is from 16.9 
to 18.5 millimeters. 
Measurements—Average and extreme measurements in milli- 
meters of a series of 14 skins in the Museum of Vertebrate Zoology 
are as follows: Total length, 135.1 (extremes 128.0-146.0) ; tail verte- 
brae, 57.7 (51.0—-62.0) ; tibia, 20.4 (19.0-22.5) ; foot, 11.1 (10.0-12.0) ; 
forearm, 51.8 (49.0-56.6) ; greatest leneth of skull 17.5 (16.9-18.5). 
Synonymy and History—The hoary bat was first deseribed by 
Peale and Beauvois (1796, p. 15) from a specimen secured in Penn- 
sylvania, probably near Philadelphia. 
Distribution—The general range of this bat is given by Miller 
(1912, p. 64) as extending throughout ‘‘boreal North America from 
the Atlantic to the Pacific, breeding within the Boreal Zone, but in 
autumn and winter migrating at least to the southern border of the 
United States.’’ The range in California in winter and spring 
comprises the valleys of west-central and southern California, south 
through the San Diegan district; in summer probably the Transition 
and Boreal zones. (See map, text-fig. R.) 
The accompanying table shows very few strictly summer records 
of the hoary bat in California. It is possible that many of the indi- 
viduals wintering here come from breeding areas north of this state. 
A discussion of the migration of this bat is given in the present paper 
under the heading Migration, on page 232. 
Specimens Examined.—The writer has examined 55 examples of 
the hoary bat from California. Since the seasonal movements of this 
species are not fully known the writer has included in the accompany- 
ing table the dates of capture as well as the localities from which 
specimens have been secured. 
Natural History.—Several hoary bats have been found hanging in 
the thick foliage of orange trees in southern California in the winter. 
On April 17, 1904, H. 8. Swarth discovered one clinging to a branch 
of an oak tree, looking like some huge gall. Stephens found the 
species in the redwoods of Mendocino County in May. He records 
