THE FAMILIES AND GENERA OF BATS. 145 



lostominse. They are now for the first time recognized as a distinct 

 subfamily. 



Principal subdivisions. — Only two genera of Hemiderminse have 

 been described. 



KEY TO THE GENERA. OF HEMIDEKMIN^E. 



Lower molars distinctly different in form from premolars; tail 

 present Hemiderma, p. 145. 



Lower molars not distinctly different in form from premolars; tail 

 absent : Rhinophylla, p. 146. 



Genus HEMIDERMA Gervais. 



1838. Carollia Gray, Mag. Zool. and Bot, II, p. 488. February, 1838. Not 



Carolia Cantraine, 1837. 

 1855. Hemiderma Gervais, Exped. du Comte de Castelnau, Zool., Mammif., 



p. 43. 

 1866. Bhinops Gray, Proc. Zool. Soc, London, p. 115 (Rhinops minor Gray= 



Hemiderma perspicillatum). 

 1878. Carollia Dobson, Catal. Chiropt. Brit. Mus., p. 495. • 

 1891. Hemiderma Lydekker in Flower and Lydekker, Mammals, living and 



extinct, p. 674. 

 1907. Hemiderma Hahn, Proc. U. S. Nat. Mus., XXXII, p. 108, February 



9, 1907. 



Type-species. — Phyllostoma brevicaudum Wied = Vespertilio per- 

 spicillatus Linnaeus. 



Geographic distribution. — Warmer parts of America north on the 

 mainland to southern Mexico, and in the West Indies to Jamaica, i 



Number of forms. — Four forms of Hemiderma are at present recog- 

 nized. 



Characters. — Dental formula: (Plates IX and X. fig. 1.) 



-2 3. 1. --34567. 2-2 1-1 2-2 3-3 QO 



1 2 -. 1. - 2 - 4 5 6 7 • 2^2' " 1^1' ■*"" 2^2' '" 3—3" 



Upper incisors strongly contrasted in size, completely filling space 

 between canines. Inner incisors large, with projecting, obliquely set 

 crowns about as high as long, strongly in contact near apex, the 

 cutting edge entire, the outer surface convex, the inner surface slightly 

 concave. Outer incisors minute, the rounded, flat crown barely rising 

 to height of cingulum of canine. Lower incisors small, forming a 

 slightly convex row between canines, the inner tooth larger than the 

 outer, its crown somewhat extended backward and distinctly concave 

 on inner surface; cutting edge of both teeth entire or slightly 

 emarginate. Canines low and strong, simple in form and without 

 secondary cusps or noticeable cingula. Premolars rather narrow, with 

 well-developed main cusps and cutting edge, but no styles; inner 

 surface slightly concave. First and second upper molar with low 

 25733— No. 57—07 m 10 



