FAMILY VESPERTILIONIDJE. 
9 
tips, forming, by its admixture with other hairs, a uniform yellowish grey. Above, the fur 
is also brownish black at bjse, and olive brown on the surface. 
Total length,_ 
_ 3-3. 
Forearm, . 
. 1-0. 
Tibia,.. 
_ 0-7. 
Spread,. 
. 9-0. 
Tail,.. 
_ 1-0. 
The Little Brown Bat appears to be subject to great variation in size and color. Usually 
they are scarcely one-half the preceding dimensions. I have received from Prof. Emmons, 
several specimens of this species, obtained in September from the northern districts. They 
are smaller, and of a dark hue approaching to black. The plaits on the anterior margins of 
the ear were not observed. The fur longer than in the specimen described above, which was 
the same employed by Mr. Cooper in his Monography. The ears appeared to be proportiona- 
bly longer ; but in the black color surrounding the mouth, and in the other characters, no 
difference could be observed. In one of the specimens, the dorsal surface was varied with 
black and grey ; and in another, dark brown intermixed with olive brown. 
The Little Brown Bat can scarcely be confounded with any other species found in this State, 
unless it be with the Carolina bat. It is found in almost every part of the Union, and ranges 
as far as the fifty-third degree of north latitude. It has been observed in New-Hampshire, 
Arkansas at the eastern base of the Rocky mountains, on the Columbia river, in Georgia, 
Pennsylvania, Carolina, &c. In this State, I have obtained specimens from the northern and 
western districts. It is very numerous about Lake Oneida, and in the southern counties. 
THE SILVER-HAIRED BAT. 
Vespertilio noctivagans. 
PLATE I. FIG. 1—(STATE COLLECTION.) 
Vespertilio noctivagans, Le Conte, McMurtrie’s Cuvier, Vol. 1, p. 431. 
V. auduboni , Harlan, Am. Jour. Geol. Vol. 1, p. 220, pi. 4. 
V. • id. Id. Med. and Phys. Researches, p. 26, plate. 
V. noctivagans, Cooper, Ann. Lyc. N., Y. Yol. 4, p. 59. 
Characteristics. Black, with silvery hairs above and beneath ; above, a whitisli collar across 
the shoulders, extending upwards towards the ears. Tail beyond the 
membrane. 
Description. Body densely hairy, particularly in the region of the neck. Ears large, broad, 
and obtusely ovate ; the outer border with a fold, producing a broad and distinct emargina- 
tion above, and an abrupt one beneath. Tragus small, ovate, dilated beneath. Nostrils ter¬ 
minal, sub-bilobate. Interfemoral membrane including all but the two last joints of the tail; 
densely hairy on the anterior part of its upper surface, becoming more sparse as it approaches 
the extremity of the tail; beneath, it is nearly naked. The bony processes of the tibia, sup¬ 
porting the sides of the membrane, are an inch long. Brachial membrane naked, except near 
Fauna. 2 
