92 BULLETIN 43, UNITED STATES NATIONAL MUSEUM. 



In specimen Nos. 29809 and 29810, Walker Pass, California, collection 

 of AgTicultnral Department, the space under the lower jaw was black; 

 tlie forearm measured 37""", the bead and body, 45"'"' ; the tail, 44"'"' ; the 

 thumb, 5""" ; the foot, 7""". 



Millimeters. 



First phalanx of the thir<l digit 12 



Second phalanx of the third digit 12 



First phalanx of the fourth digit 9J 



Second phalanx of the fourth digit 9^ 



First phalanx of the fifth digit 8^ 



Second phalanx of the fifth digit 6 



V. albescens mehoiorhinus is essentially the same as the melanic I'orm of 

 V. albescens, 'excei)tm<^ that the tips of the hair of the under surface of the 

 body are whiter than is the rule with this species and the tragus is more 

 than usually crenulated, and two of the situations are exceptionally deep 

 near the basal part of the outer border. That tlu^ hair is disposed to 

 be white on the uiuler surface of the body is suggested by the names 

 albescens and leuaogaster. In a bat otherwise black, this contrast of 

 color is striking. 



Var. (c). Vespertilio albescens velifer (J. A. Allen). 



Dr. J. A. Allen (Bull. Am. Mus. Nat. Hist, No. 1, p. 177, 18) has 

 described a species of Vespertilio from Mexico, which he believes to 

 unite the characters of T^. albescens and V. subulatus (= V. (jryplins). I 

 have examined the skins upon which this diagnosis has been made and 

 believe the form to be a variety of Y, albescens. The following is the 

 text of Dr. Allen's description : 



Vespertilio velifer, sp. nov. 



Size of V. albescens, with nearly the coloration of V. nitidns and the ears of V. sub- 

 ulatus. 



Ahove basal two-thirds of the fur blackish, passing into dark broccoli brown at 

 the surface; below much paler, the surface pale buffy gray. Pelage full and soft, 

 extending on the membranes about as in V. lucifuf/iis. Ears of medium size, similar 

 in general form to those of V. subulatus, but rather narrower and more attenuate at 

 the tip, the upper posterior third distinctly hollowed, the lower third abrubtly much 

 expanded; tragus long, rather narrow, fully or rather more*han half the length of 

 the ear, the front border nearly straight, the posterior Ijorder slightly rounded as 

 far as a little beyond the middle, then sloping gradually to the rather narrow, but 

 rounded tip, with a distinct notch opposite the anterior base. 



Wings from the l>ase of the toes; calcaneum strongly developed, feet large; thumb 

 short, stout, with a rather thick claw ; tip of last caudal vertebra free. 



Length of head and body (measurements from dry skin), 44'""'; tail, 33"""; ear, 

 from base of inner margin, I4"i"ij tragus, 9"'"'; forearm, 42'"">; thumb, 8"'"'; third 

 finger (nu'tacar])al, 38'""^; first phalanx, 13"""; second phalanx, 12"""; third phalanx, 

 10"'"'), 73'""'; tibia, 17"""; foot, ll'""\ 



Skull broad, rather short ; basilar length, 14'""' ; total length, 16'""^' ; greatest width, 

 10.5"""'; lower jaw (front border to condyle), 13'"'". First upper premolar about 

 twice the size of the second, both ])laced on th<^ inner border of the tooth row. 



Type, 2696, ad., Sta. Cruz del Valle, Guadalajara, Jalisco, September 7, 1889, Dr. 

 A. C. BuUer. 



