1861.] MR. R. F. TOMES ON THE GENUS VAMPYRUS. 107 



branes extending to the extremity of the tibia. Nose-leaf of mode- 

 rate size, adherent to the Up in front. 



Dentition. — Incisors ^ ; premolars ^. 



The dentition of this species resembles that of the Phyllostoma 

 elongatum of Geoffroy. 



Ex. Vampyrus bidens, Spix. 



Tylostoma bidens, Gerv. Voy. Casteln. 185.5. 

 Phyllostoma childreni, Gray, Mag. Zool. Bot. ii. 1838. 

 Phyllostoma bidens of the Paris Museum- 

 Phyllostoma lituratum of the Ley den Museum. 



Obs. M. Gervais gives the Vampyrus bidens of Spix, and the 

 Phyllostoma crenulatum of Geoffroy, as the types of his genus Tylo- 

 storna. The latter of these two species I have not examined, but 

 have suspected that it might prove identical with the Vampyrus cir- 

 rhosus of Spix. Dr. Gray's Trachops fuUginosus is, however, iden- 

 tical with V, cirrhosus ; and having lately examined the species from 

 which Dr. Gray took his description, I am able to state that it has 

 four lower incisors, whereas the Phyllostoma crenulatum (according 

 to M. Gervais) has two only. 



G. {Trachops, Gray ; Tylostoma, Gervais, in part ? ; Vatnpyrus, 



Spix.) 



General form and proportions as in Mimon. Ears, tragus, and 

 hinder extremities similar. Nose-leaf of two distinct parts— an an- 

 terior horse-shoe, having its front margin scarcely raised from the 

 hp, and a posterior hastate portion springing from the centre of the 

 horse-shoe. All the margins of the nose-leaf crenulated ; and the 

 lower lip and chin thickly covered with small but prominent warts. 



Dentition. — Incisors -^ ; premolars ~. 



The only respect in which Trachops can be said to differ materially 

 from Tylostoma, is in being possessed of four lower incisors, and in 

 having the nose-leaf and chin marked with crenulations and warts. 



Ex. Vampyrus cirrhosus, Spix. 



Trachops fuUginosus, Gray, P. Z. S. 1847. 

 Phyllostoma crenulatum, Geoffroy 1 



Observations on the foregoing sjiecies.— The species, the charac- 

 ters of which I have given above, constitute a group, of which the 

 most obvious peculiarities are the great development of the mem- 

 branes and ears, the rounded form of the wings, and the length and 

 softness of the fur. These superficial characters are common to all 

 of them. The simple and entire form of nose-leaf is a peculiarity 

 which most of them possess ; and those which do not, have their 

 membranes also less remarkably developed. 



In the shape of the cranium there is considerable discrepancy in 

 the several species, the chief difference consisting in the greater or 

 less degree of elevation of the cerebral region ; and as this appears to 



