326 VESPBHTILIONIDiE. 



slightly outwards ; inner margin straight below, slightly convex 

 above ; outer margin with a distinct horizontal lobule at its base, 

 then convex, attaining its greatest convexity slightly above the base 

 of the inner margin ; upper third concave. 



Wings to the metatarsus ; feet large and strong ; interfemoral 

 membrane acutely angular behind as in V. capacdni ; last caudal 

 vertebra and half the antepenultimate vertebra free ; calcaneum 

 long, extending three fourths the distance between the ankle and 

 tip of the tail. 



Above, the fur extends upon the wing-membranes as far as a line 

 drawn from the middle of the humerus almost as far as the knee- 

 joint ; the base only of the interfemoral is covered, and a few hairs 

 appear on the backs of the toes. Beneath, the wing-membrane is 

 clothed to a slightly greater extent, and the greater part of the 

 interfemoral, especially along the taU and inside the legs on each 

 side, is covered with fine short whitish hairs. 



Above dark brown, with sienna-brown tips ; beneath black, with 

 whitish extremities. 



Length, head and body l"-8, tail 1"*3, ear 0"-5, tragus 0"-28, fore- 

 arm l"-3, thumb 0"-25, third finger 2" (metacarp. 1"-15), fifth finger 

 l"-7 (metacarp. 1"-1), tibia 0"-6, foot 0"-35. 



Hab. North America. 



a. ad. sk. N.W. America. 



41. Vespertilio albescens. 



Vespeitilio albescens, Oeoffroy, Ann. du Mus. viii. p. 204 ; Temminck, 

 Monogr. Mammal, ii. p. 244 (1840) (vide Peters, MB. Akad. Berl. 

 1866, p. 19). 



Vespertilio leucogaster, Wied, Beitr. Naturg. Brasil. ii. p. 271 (1825). 



Vespertilio nubilus, Wagner, Suppl. Schreh. Sdugeth. i. p. 534 (1844). 



Muzzle rather long and thick ; crown of the head scarcely 

 elevated. Ears shorter than the head; laid forwards the tips do 

 not reach to the end of the muzzle ; the horizontal margin of the 

 inner basal lobe of the ear straight, forming a right angle with the 

 ascending portion of the outer margin, which is straight for nearly 

 two thirds its length, then slants upwards and backwards ; tip very 

 narrowly rounded off; the upper half of the outer side flatly 

 emarginate, so that the upper third of the ear is abruptly narrowed, 

 but the tip does not project outwards ; lower half gradually convex, 

 with a very faint angular emargination opposite the base of the 

 tragus terminating in a small, slightly convex lobe. Tragus long 

 and subacutely pointed, attaining its greatest width slightly below 

 the middle of the inner margin ; the outer margin convex upwards 

 for two thirds its leng-th, then faintly concave ; inner margin corre- 

 spondingly convex above. Although the inner margin is more 

 convex than straight, the tragus is scarcely inclined outwards, 

 and in some specimens (as in that from which the accompanying 

 illustration of the form of the ear was taken) the inner margin is 

 concave, and the tragus consequently inclined inwards. (Plate XIX. 

 fig. 8, ear, enlarged.) 



