1918] Grinnell: A Synopsis of the Bats of Califorma 227 
Academy of Natural Sciences, Philadelphia; 20 from the collection 
of the Department of Zoology of the University of California; 20 
from the American Museum of Natural History, New York; 17 from 
the collection of the California Academy of Sciences, San Francisco ; 
9 from the Museum of Comparative Zoology, Cambridge; 9 from the 
collection of the San Diego Society of Natural History; 5 from the 
collection of Frank Stephens; and 1 specimen from the collection of 
Rea Weakoch 
Many specimens of bats from outside of the State of California 
have been used in comparison, and these are also from the above- 
named sources, and from the Museum of the Canadian Geological 
Survey, Ottawa. 
The material examined has consisted chiefly of dry skins with 
skulls; but it has generally been possible to secure fresh and alcoholic 
specimens from which to derive the essential supplementary data. 
MEASUREMENTS 
Throughout this paper all measurements of total length, tail 
vertebrae, and foot are as taken in the flesh by the collector, unless 
otherwise stated. These are likely to be somewhat longer than meas- 
urements obtainable from dried skins or from alcoholic specimens. 
Since averages are useful only for comparison with other averages, 
detailed measurements of specimens are given wherever possible. In 
selecting specimens for measurement examples have been chosen which 
show extremes of variation, as far as contained in the material at hand. 
All measurements are stated in millimeters. In the fresh specimen 
it 1s customary to measure the total length, and lengths of tail, foot, 
ear, and tragus. To do this with facility, the bat should first be laid 
out flat upon its back, when the total length from end of nose to tip 
of tail, may be taken. When the tail is to be measured one point of 
a pair of dividers should be set on the rump at the extreme base of 
the tail and the other point placed at the tip of the straightened tail. 
The foot should be measured from the tip of the longest claw to the 
upper edge of the heel. Two methods of measuring the ear are used 
and as these differ somewhat in results the particular one used should 
always be specified. One is ‘‘ear from crown,”’ and is taken with 
one point of the dividers set on the skull on the inner (convex) side 
of the ear and the other at the tip of the ear. The second method, 
and one which results in a slightly longer measurement, is ‘‘ear from 
