1895. PROCEEDINGS OF THE NATIONAL MUSEUM. 773 



Tlie lower lip, as already mentioned, does not i)resent a square-sided 

 naked surface but is indistinctly cleft. See figure in Alston's account.' 



Auricle subrounded, entire, with obscurely developed, internal basal 

 and external basal lobes. Tragus erect, broad, naked, abruptly acumi- 

 nate, thickened on surface near apex. The outer border not spinose or 

 crenulate; external basal lobe small, external basal notch sliallow. 



The membranes do not present any noteworthy features. The radius 

 exhibits a humeral trochlea which is mucli deeper than in Dcsmodns. 

 The ulna ends at the distal end of the middle third of the radius by 

 anchylosis with that bone, but no flange extends its line toward the wrist 

 as is the case with Desmodus. The radius is articulate with the humerus 

 by a surface which is concave in the middle and convex on the borders. 

 The distal end of the humerus exhibits anteriorly a rounded convexity 

 in the middle and concave borders ; the epicondyle is of great size (equal 

 to two-thirds of the articular surface), and projects horizontally. 



The iuterfemoral membrane is rudimental and is confined to a mere 

 hem on the inside of the thigh and leg. In Desmodus the membrane 

 extends across the iuterfemoral space as an apron, 12 mm. wide. These 

 contrasts lead me to conclude that the two genera exhibit i)eculiarities 

 in wing movements which correlate with wing characters, but the 

 materiiil at hand is insufHcient to establish them. The following con- 

 trasts with Desmoihis are tabulated: 



COMPARISON Ol' THK CHARACTEKS OK I>IPHYLT.A AND DKSMOnUS. 



DiphuUn. 1 Desmodas. 



Humei-iil trochlea deep. 



Radius without ridge distal to ulna. 



Prebrachium uiembraue extends to 

 wrist. 



Iuterfemoral membrane conlined to in' 

 ferior extremities as a hem. 



Gland-masses at sides of muzzle scarcely 

 meet across face-vertex or not at all. 



Tragus naked. 



One-third length of thumb occupied by 

 the metacarpal bone, whose base does not 

 retain a conical callosity. 



Humeral trochlea shallow. 



Radius with ridge distal to ulna. 



Prebrachium membrane extends to mid- 

 dle of radius. 



Iuterfemoral luembraue crosses space 

 between inferior extremities. 



Gland-masses at sides of nnizzle meet 

 across face-vertex in a high subconical 

 skin fold. 



Tragus hairy. 



One-half the length of thumb occupied 

 by the metacarpal bone, whose base re- 

 tains a ccmical callosity. 



.4121 , 

 Dental for mil la.— I ^ c -^ p 3 ni -^ x 2=64:. 



Upper teeth.— The enormous central incisors larger than the canines. 

 They are trenchant, opposed for the one-third tlieir length, the lanceo- 

 late\ioints being distinct. The posterior concave surfaces are almost 

 contiguous to the canines. The very minute noduhir lateral incisors 

 lie to the inside of the canines. The premolars compressed with knife- 

 like edges, obscurely pointed — the first with a simple, th e se cond with 

 " 1 Biol. Centrali-Americana, 1879-1882, p. 53, pi. in, fig. 6. 



