Bats 
279 
long, basal lobe well developed, but not excessively large; tragus 
straight, short, directed slightly forward, broadest near the middle 
and tapering to a moderately sharp point. Back of interfemoral 
membrane wholly naked, except for a sprinkling of hairs on basal 
fourth. Mammae 2. Dentition, i. |; c. |; pm. ^;m.§ X 2 = 32. 
About 45 species are known in this genus, found in Africa, 
Madagascar, Australia, Asia (except Malay Region), America 
from southern Canada southward (except Lesser Antilles). 
Two species, with eight subspecies, are found in North 
and Middle America and West Indies, of which two are 
found in Colorado and are among the largest of our bats. 
Key of the Species 
A. Color brown, moderately dark ; size smaller than B ; length about 
4.5; forearm, 1.75. E. fuscus, p. 279 
B. Color brownish ashy above, pale gray below ; size larger, length, 
4 9; forearm, 1.9. E. pallidus, p. 280 
Eptesicus fuscus (Lat. dark, dusky). Brown Bat 
Vespertilio fuscus Beauvois, Catal. Peale s AIus., p. 14 (1796). 
Type locality. — Philadelphia, Pennsylvania. 
Measurements. — Total length, 4.5 ; tail vert., 1.75 ; hind foot, 0.4; 
forearm, 1.75. Length of skull, 0.7; width, 0.5. 
Description. — (From a specimen taken at Colorado Springs, 
Aug. 4th): Dark bi-own on back; paler, rather grayish on under 
parts; ears and membranes blackish. 
Cranial and dental characters as for genus. 
Excepting the two species of Nycteris this and the next species are 
the largest Colorado bats, and it may easily be distinguished from 
them by its brown color and the practically naked dorsal surface 
of the interfemoral membrane. 
Distribution. — Austral, Transition and (lower edge of) Boreal 
zones throughout the United States and adjoining British Provinces 
(Miller, I. c). He records it from Loveland. Other Colorado locali- 
ties are Greeley (Beardsley); Florida, La Plata Co. (Rowley); 
Colorado Springs, Douglas Spring, Routt County, Newcastle 
(Warren). 
Habits. — J. W. Frey and myself took twenty-one specimens 
of this species at Newcastle in rather a peculiar manner. We 
had been told that there were a lot of bats behind the shutters 
