Bats 
277 
half length of anterior margin. Back of interfemoral membrane 
furred on basal half. Mammae 2. Dentition, i. f; c. {; pm. |; 
m. ^ X 2 =36. 
Small dark-colored bats, represented only by the type 
species which is distributed from northern North America 
south through the United States, and has been taken at 
several localities in Colorado. 
Lasionycteris noctivagans (Lat. nox, night, vagans, to 
wander). Silver-Haired Bat. 
Vespertilio noctivagans LeConte, McMurtrie's Cuvier's Animal 
Kingdom, i., p. 31 (183 1). 
Type locality. — Eastern United States. 
Measurements. — Total length, 3.75; tail vert., 1.5; hind foot, 
0.37: forearm, 1.6. Length of skull, 0.55; width, 0.35. 
Description. — (From a specimen taken in Garfield County, July 
13th): Fur on both back and under parts deep blackish chocolate 
brown, many of the hairs on back and belly tipped with silvery 
white, but these white tips are absent from head and throat. 
Membranes blackish. 
Cranial and dental characters as for genus. The very dark 
color, with silvery tipped hairs distinguishes it from all other species 
of bats occurring in Colorado. 
Distribution. — North America, from Atlantic to Pacific ; probably 
not breeding south of the Transition Zone (Miller I. c). Preble 
reports it as far north as Lat. 56°. Miller records it from Rifle; 
it has also been taken at Greeley (Beardsley, Hall) ; Florida, La 
Plata Co. (Rowley) ; near Colorado Springs (Sclater) ; West Fork, 
Elk Creek, eight miles above New Castle, and Green Mountain 
Falls (Warren); Salida (Frey); Boulder (in Museum of University 
of Colorado). 
Genus PIPISTRELLUS (pipistrelle, the name of a European Bat) 
Pipistrellus Kaup, Skizzirte Entwick.: Gesch., u. Naturl. Syst. d. 
Europ. Thierw., Th. i., 98 (1829). Type, Vespertilio pipistrellus 
Schreber. 
Revision, Miller, A^. A. Fauna, No. 13 (1897). 
Skull small and lightly built, varying somewhat in form among 
the different species; brain-case usually more inflated than in 
Vespertilio and Lasionycteris, but rostrum proportionally as broad 
as in these genera. Ears distinctly longer than broad, and tapering 
