Vesperago from North America. 125 



evenly convex to the broad tip, the internal margin concave, 

 at the base of the outer margin a longitudinally-directed 

 lappet, succeeded above by an emarglnation, above which the 

 outer margin is evenly convex ; pollex short, feet very small, 

 postcalcaneal lobule shallow, extreme tip of the tail alone pro- 

 jecting ; the interfemoral membrane is naked above, except 

 at the root of the tail, beneath a few short hairs appear along 

 the transverse lines : fur pale yellowish brown on both sur- 

 faces, paler beneath, the basal half or more of the hairs dusky ; 

 margin of the wing-membrane from the last finger to the foot 

 whitish. 



Upper incisors unicuspidate (as far as can be seen from a 

 single specimen), the inner one on each side much longer and 

 thicker than the outer, which is close to it ; lower incisors 

 placed in the direction of the jaws ; first upper premolar very 

 small, in the angle between the canine and the second pre- 

 molar, and not visible from without, although the cusp of the 

 second premolar is widely separated from that of the canine 

 owing to the projecting anterior part of the cingulum of the 

 former tooth ; the first lower premolar is much shorter than 

 the second, which considerably exceeds in height the cusps of 

 the molars. 



This is the smallest species of the subgenus yet described, 

 the forearm scarcely exceeding an inch in length. That the 

 single specimen known is full-grown is proved by the worn 

 state of the teeth and perfectly ossified condition of the finger- 

 bones. It somewhat resembles V. ahramus of the Old World, 

 but may be at once distinguished by its unicuspidate upper 

 incisors and by the lower incisors being placed in the direc- 

 tion of the jaws, by the shape of the second upper and lower 

 premolars, by the small size of the first lower premolar, by 

 the very differently-shaped tragus, and finally by the con- 

 spicuously small size of the animal. The discovery of this 

 species is of peculiar interest, as it belongs to a subgenus 

 which, though largely represented in the Old World, is very 

 restricted in the New. 



Length (of an adult male) : head and body 1"*5, tail 1", 

 head 0"-5, ear 0"-38, tragus 0"'18, forearm l"-05, pollex 

 0"-15, middle finger l"-6, fifth finger 1"'2, tibia 0''-4, 

 foot 0''-2. 



Hob. North America (Locust Grove, State of New York) . 

 I have much pleasure in connecting with this very inter- 

 esting species the name of its discoverer, Dr. Clinton Hart 

 Merriam, author of the ' Mammals of the Adirondacks,' who 

 has done so much to extend our knowledge of the mammalian 

 fauna of the Neavctic Region. 



