A MONOGRAPH OF THE BATS OF NORTH AMERICA. 03 



Three siieciineiis, one male and two females, and six adilifional sknlls, Sta. ( 'niz 

 del Vallo, (Jnadalajara, Jaliaeo, Sei>tember 7 and S, IHH[). 



These specimens agree very closely in size and coloraticm and in all other charao- 

 ters, and represent an apparently new species, ([uite different from any hertitofon; de- 

 scribed. Its large size readily distinguishes it from any other known Mexican or 

 North American species of the genus, except f. albescens Geoffroy, whicli it ajjpears 

 to equal in size, while differing from it almost as widely as possible in coloration, 

 and also greatly in the size and form of the ear and in the very differently shaped 

 tragus. Fortunately a Maximilian si)ecimen of T. Iiiicogastcr Wied., a species cur- 

 rently synonymized with V. albcscom (see Dobson, Cat. Chirop., pj). 326, 327). in the 

 American iluseum, enables me to make a direct comparison of V. <iJIh:scviix with the 

 present species. 



I lijive received a bat from Mr. G. S. Miller, jr., who obtained it from 

 Dalyura, Cal., which answers so closely to 1". aJbe.sceii.s velifer (J. A. 

 Allen) as to be at least a variety of this subspecies. The free margin 

 of the interfenioral membrane from the calcars to the tip of the tail is 

 consiiicuously timbriated. The fur above is of a light tawny brown of 

 the same shade as is met with in many Californian specimens of Ade- 

 lonycteris fuHCUs. The under surface is tipped with white throughout, 

 after a manner precisely the same as in V. albescens. The basal parts 

 of the fur both above and below is intensely black. 



Var. («) Vespertilio albescens afEiiis (H. Allen). 



Under the name of YefiijerUlw affinis in the Monograph of 180-4 (p. 

 53) I describe an immature bat as follows : 



r. affinis. — Head moderate, slightly depressed; face hairy; ears rather small, inner 

 border convex, outer border concave. Tragus is subulate, about half as high as the 

 ear, straight oninternal side, diverging on the external. Lip whiskered. I?ody 

 robust. Feet long and slender; a few curved hairs at the base of the nails; wing 

 membrane, attached midway to base of toes. Interfenioral membrane rather small; 

 a little lobe at the termination of the calcaneum; point of tail exserted. Thumb 

 rather large. Wing membranes dark brown, but thin. 



Fur thicker behind than before and extending a slight distance on the inter- 

 fenioral membrane. Color lustrous light chestnut brown above; the same color of 

 a lighter shade, inclining to yellowish below. The base of the fur above and below 

 is of a delicate fawn brown. 



The dentition is the same as in V. erotis, the incisors being tlie same length, the 

 laterals bicuspid. 



r.affi)iiii resembles .S'. georr/ianns ( Vespcrugo) in b(>ing about the sann^ size and in the 

 fur and membranes jiresenting the same general ai)i)earance. It differs from that 

 species in having tlie ear more emarginated on the outer border ; the tragus not blunt, 

 nor so wide proportionately ; the face more hairy and not so depressed ; the reddish hue 

 of the hair more decided ; the fur thicker and less wavy. The dentition differs in there 



being - molars, instead of " . V. affinis has also a narrower interfenioral ineni- 

 6 5 



brane and a marked caicareal lobe. On the dorsum the basal third of fur chestnut 

 brown, apical half two thirds lighter brown. The venter basal third deep brown 

 (quite a different shade than that of the dorsum), while the tips are of a light gray, 

 verging to white. The membranes from the tarsus. The coloration and the attach- 

 ment of the wing membrane to the foot distinguish this variety. For the standard 

 which existed for species at the time it was described, warranted its being placed 

 under a separate heading from r, subtdatus. It is immature, 



