NATURAL SCIENCES OP PHILADELPHIA. 281 



tragus subulate, basal cusp turned forward ; nostrils palmate, inferior border 

 not well defined nor much swollen above ; lower lip not free. Membrane to 

 base of toes ; tubercle at base of fibula very faint, as the calcaneum is slightly 

 developed. Membrane over both of the same color as that elsewhere; joints 

 of tail ten, terminal one half ezsert. Teeth. Central incisor in line of arch, the 

 medial cusp the larger ; lateral more at right angles to arch ; posterior cusp 

 much smaller than anterior ; palatal ridge absent; first and second premolars 

 subequal, the first being slightly the larger, and both thrown slightly inward 

 from dental arch ; molars, . Inferior lateral incisors quadri-lobed. 



Measurements. 



Head V" Foot 3'" 



Body 11'" Auricle 6'" 



Tail 1".4'" Tragus 5'" 



Humerus l''-4'" Length 2d joint index finger 2'" 



Thumb 2"' Expanse 9" 



Two individuals. Nos. 1114, 1115, Mus. of Academy. Alcohol. 

 San Salvador. 



V. exigcus, n. s. 



Fur above basal three-fourths blackish; apical fourth grey. Toward the 

 coccyx the basal hue is more brownish, the tip glistening brown. Basal 

 third of upper surface of inter-femoral membrane covered with a thin patch 

 of nearly unicolored glistening hair. Beneath fur more tri-colored ; thin line 

 of whitish hairs at base; distal two-thirds blackish-fawn, apical third grey- 

 ish. Toward the pubis hair almost white, mixed with dirty yellow, and the 

 membranes to near elbow and basal third of interfemoral membrane possess 

 a scattering pelage of the same hue. Tip of auricle bluntish, internal basal 

 acute, external basal well marked, broadly crescentic ; tragus narrow, acuminate, 

 emarginate on the upper two-thirds ; nostrils with a well-defined lower edge, 

 palmate (as in 5547); membrane to base of toes ; joints of tail nine ; scarcely 

 any ex-calcaneal lobe ; calcaneum slender. Teeth as in V. mundus. Indi- 

 vidual young, and the second premolar above is not yet fully erupted. Late- 

 ral incisors below obscurely quadrilobed. 



Measurements. 



Length of head V" Length of foot 4"' 



" " body 1'" " " auricle 6'" 



" " tail l"-2"' " " tragus 3'" 



" " humerus"l"-4"' " " 2d joint index finger 2'" 



" " thumb 3'" Expanse 8" 



One individual, $. No. 5373, Mus. of the Smithsonian Institution. Alcohol. 



Aspinwall, N. G. Dr. Hayer. 



V. obscurus, n. s. (No. 8223 type.) 



Fur above dark plumbeous at basal two-thirds ; woolly texture and obscure 

 fawn-brown at apical one-third. Below basal two-thirds blackish, apical 

 one-third yellowish-white ; more russet under jaws ; face very hairy ; mem- 

 branes furred ; lateral lower incisor square quadrilobed, raised considerably 

 above level of other teeth ; upper premolars in line, first little longer ; lower 

 premolars same ; interfemoral membrane triangular ; joints of tail nine, ter- 

 minal joint conspicuously exsert. Ear, external basal lobe irregularly quad- 

 rate ; other parts as other species of N. A. Vespertilio. Nostrils with lower 

 border everted, not elliptical. 



Mutilated. 



(8222.) Fur above basal two-thirds dark brownish-black, streaked with 

 bright olive-brown hairs at base ; apical one-third glistening olive-brown 

 below; basal four- fifths brownish- black, streaked with yellowish hairs at 



1866.] 



