PIPISTRELLUS. 583 
Geogr. Distr. Lower California, Mexico, to western Texas. 
Genl. Char. Size small; ear reaching to nostril, short and rounded 
at tip; tragus curved forward at tip; end of tail free of membrane. 
Color. Light yellowish gray, hairs plumbeovs at base; between 
fourth and fifth finger, the border of wing membrane is whitish; ears, 
face muzzle, and membranes black. 
Fic. LXXXVI. PIPISTRELLUS HESPERUS. 
No. 10851 Field Columbian Mus. Coll. Trifle more than twice nat. size. 
Measurements. Total length, 72.8-79; tail vertebrae, 28-34.5; 
tibia, 11-12.8; foot, 5-6; forearm, 28—-32.5; thumb, 4; longest finger, 
48-55.5; ear from meatus, 1o-12.4; width of ear, 8.6—9.6; tragus, 
4.6-5.4. Skull: occipito-nasal length, 11; zygomatic width, 7 ; width of 
braincase, 6; occipital depth, 4. 
a.—apus (Prprstrellus), Elliot, Pub. Field Columb. Mus., 111, 1904, 
p. 269. Zodlogy. 
Swirt Bart. 
Type locality. Providentia Mines, State of Sonora, Mexico. 
Genl. Char. About the size of P. hesperus, but quite different in 
color, and with a larger foot. Larger than P. h. australis, the exact 
color of which is not known. 
Color. Upper parts wood brown, base of fur blackish; under 
parts pinkish brown; nose, space before and around eyes, wing, and 
tail, membranes, feet, and ears black. 
Measurements. Total length, 72; tail vertebra, 31.7; foot, 6.3; 
forearm, 30.5; thumb, 4; longest finger, 47; ear from meatus, ro. 
Skull: occipito-nasal length, 10.5; zygomatic width, 8; interorbital 
constriction, 3; width of braincase, 6.5; palatal length, 5; post-palatal 
length, to anterior rim of foramen magnum, 4; length of upper tooth 
