FAMILY VESPERTILIONIDiE. 9 



tips, forming, by its admixture with other hairs, a uniform yellowish grey. Above, the fur 

 is also brownish black at base, and olive brown on the surface. 



Total length, 3-3. Forearm, I'O. 



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 BrowaBat 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. 



Vespehtilio noctiyagans. 

 plate i. fig. 1. — (state collection.) 



Veajxrtilio noctivagam, Le Contb, McMurtrie's Cuvier, Vol. 1, p. 431. 

 V. auduboni, Harlan, Am. Jour. Geol. Vol. 1, p. 220, pi. 4. 



y. id. Id. Med. and Phys. Researches, p. 26, plate. 



V. noctivagam, Cooper, Ann. Lye. N. Y. Vol. 4, p. 59. 



Characteristics. Black, with silvery hairs above and beneath ; above, a whitish 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 



