August, 1910. MAMMALS FROM SOUTH AMERICA OSGOOD. 31 



nences from which slender ridges extend backward about 6 mm. ; 

 six small papillae on each side of the face, two pairs behind each nos- 

 tril and one pair behind each upper lip; ear slightly lobulate termi- 

 nally. Color of upperparts a little lighter than mummy brown; a 

 narrow, whitish median streak from the interscapular region back- 

 ward; underparts tawny olive, somewhat brighter on the sides near 

 the base of the volar membrane. 



Measurements. Head and body 67; tail 12;. ear conch, inner 

 margin 17.5, outer margin 20.5, breadth 8.7; tragus 4; forearm 

 58.4; pollex 10; 3rd metacarpal 51.5; 4th metacarpal 52.5; 5th 

 metacarpal 50.4; foot with claws 15.6; tibia 21.5; calcar 30.5. 

 Skull : Condylion to front of canine 17.2 ; zygomatic width 14.6; mas- 

 toid width 12.6; width of braincase 11.2; inion to anterior division 

 of sagittal crest 12.5; upper teeth, c-m 3 7.5; width of m 2 2.7. 



Remarks. The differences between the above-described species 

 and Noctilio albiventer are quite convincing of their distinctness 

 although only one specimen of each has been available for comparison. 

 Of these, one (the type) is in alcohol and the other is a dry skin from 

 Brazil, kindly loaned by the authorities of the U. S. National Museum 

 through Mr. N. Hollister, Assistant Curator of Mammals. No com- 

 parison has been possible with Noctilio zaparo Cabrera but since that 

 species is even larger than Noctilio albiventer it need not be considered. 

 Careful comparison of -Y. albiventer and -Y. minor with a specimen of 

 -Y. leporinus mastivus shows so much detailed similarity throughout 

 even to minor external features and color, that it is difficult to sub- 

 scribe to their generic separation. The genus Dirias, with Noctilio 

 albiventer as type, has been separated from Noctilio (type N. lepo- 

 rinus} on the basis of a proportionately shorter tibia and foot, slight 

 spaces between upper molar teeth, and the development of a well- 

 defined commissure from the hypocone of m 1 and m 2 to the commissure 

 extending from the protocone to the metacone.* The commissure 

 is not absent in A*, mastivus but merely not so well developed as in 

 A . albiventer. But in N. minor, the commissure is scarcely more 

 prominent than in A T . mastivus, while the spacing of the upper molars 

 is practically the same as in that species, due allowance being made 

 for the disparity in size. In dental characters, therefore, A', minor 

 is intermediate between "Dirias" and Noctilio and even nearer to 

 the latter; while in the relative shortness of its foot and tibia it differs 

 from typical Noctilio even more widely than does albiventer, the 



* See Miller, The Families and Genera of Bats, Bull. 57, U.S. Nat. Mus., p. 99. 1007. 



