272 ]Mi'. O. Thomas on Mammals from 



dull wliitisli, the back gradually becoming browner, the rump 

 pale "wood-brown." Under surface dull buffy whitish. 



Dimensions of the type (the starred measurements taken 

 in the flesh) : — 



Forearm (approximately) 54 mm. 



Head and body* 62 ; tail* 121; hind foot* 11 ; ear* 12. 

 Tragus on inner edge 4, breadth 2"8. Third finger, meta- 

 carpus 56, first phalanx 10 ; tibia 19, hind foot (c. u.) 9 ; 

 calcar 16 



Skull : greatest length (occiput to base of canines) 16 ; 

 basi-sinual length 11*6; zygomatic breadrh ] 1*5 ; breadth 

 across orbits 8 ; mastoid breadth 9'2 ; palato-sinual length 

 3*7 ; front of/)* to back of m^ 5. 



Hah. as above. 



Tt/pe. Adult male (softened and placed in spirit). B.M. 

 no. 20. 7. 14. 24. Original number 73. Collected 17th 

 October, 1916, by Fraulein E. Snethlage. 



This new bat forms a most interesting discovery, adding a 

 third genus to the small subfamily Diclidurinfe. It is in ail 

 respects less highly specialized tlian DicUdurus, the well- 

 known white bat of the Neotropical region, whicli, until tiie 

 discovery of Gyttarops in 1913 f? was supposed to be entirely 

 isolated from all its allies. In colour the white DicUdurus 

 remains unique, for both Gyttarops and Depanycteris are 

 brown, though the latter is an unusually pale brown. 



20. Noctilio leporinuSj L. 



(J . 51 ; ? . 52, 53, 54. Ladeira Grrande, Ceard {F. Lima). 



All with well-marked dorsal streaks. No. 52 is strongly 

 fulvous both above and below ; the others are brown above 

 and whitish below. 



21. Dirias albiventer, Spix. 



c?- 59; $.60,61,62. Ilha da RoQa, Marajd (i^. Lm«). 



The same variation in the colours occurs as with the 

 Noctilio, and is equally independent of sex. 



Mr. Osgood's observations \ about the teeth of Noctilio and 

 Dirias and the uselessness of the dental characters for distin- 

 guishing the two genera are undoubtedly quite correct, as I 

 have verified by tiie examination of many forms of both 

 groups. But I am none the less disposed to consider that 

 the striking difference in the proportions of the legs and feet 



t Ann. & Mag. Nat. Hist. (8) xi. p. 134 (1913). 

 t Field Mus. Publ. x. no. 4, p. 81 (1910). 



