1890.] 73 [Allen 



Mr. Allen sent to me eight crania for inspection. The characters of these 

 specimens are in many respects quite different from those of M. californi- 

 cus. I have therefore concluded to describe the Mexican species as new in 

 the following language : 

 MACROTUS BULLERI, sp. nov. 



Auricle scarcely longer than head ; the internal basal lobule rudi- 

 mental and projects about a millimetre beyond the juncture of the 

 interauricular membrane. External basal lobe reduced to a thin ridge 

 which leaves the tragus exposed. Tragus with convex anterior border for 

 basal two-thirds, and an abruptly acuminate apical third. The outer bor- 

 der is straight apparently without basal notch or lobule. 



The nose-leaf without well-defined lower border scarcely longer than 

 the face. Chin apparently without divided plate. 



Skull. Facial region without depression on the frontal bone ; indeed, it 

 is faintly ridged posteriorly ; region over ethmoid scrolls scarcely inflated. 

 Squamosal portion of zygoma not more than one-half the size of the same 

 part in M. calif ornicus. No projection of vertex at occiput, but the entire 

 superior curvature of the head simple. Angle of mandible projects 

 scarcely at all back of the condyloid surface. The two halves of the 

 mandible closer together than in M. calif ornicus. 



Fur. On the back the basal two-third is white, the apical third very 

 dark plumbeous, the tip tending to gray. These distinctions are best 

 defined on the sides of the neck. At the middle of the back the gray tip 

 is absent. The colors undergo no variation over the posterior surface of 

 the prebrachium, the humerus, or the rump. On the endo-patagium the 

 hairs are shorter, sparsely developed, and of a fawn color throughout. 



On the ventre a disposition exists for the basal two-thirds of the hair 

 to be whiter than the rest of the hair. This is most marked on the sides 

 of the trunk, and is nearly absent from the middle. The apical third is 

 less markedly plumbeous and the tip is more gray than on the back. On 

 the whole the ventre gives the impression of being gray, and the back as 

 being of a, dark, sooty hue. 



Two immature examples (the distal epiphyses of the metacarpal bones 

 of the third, a fourth, and fifth, manal digits ununited), 2004, 2005 (Am. 

 Mus., N. Y.), from Bolanos, Jalisco, Mexico. 



Measurements. 



Height of auricle from vertex ..................... 7 mm. 



tragus (slightly distorted) ................ 6 " 



" nose-leaf ................................ 7 " 



Length of forearm ................................. 44 " 



( m. c ................................... 4 " 



1st digit. . J fi rst phalanx .......................... 4 " 



. . 



(second" .......................... 2 " 



' C ................ .................. 4 |! 



first phalanx .......................... 5 



PROC. AMER. PHILOS. SOC. XXVIII. 132. J. PRINTED MAY 10, 1890. 



2d digit...] 

 ( 



