216 DR. KNUD ANDERSEN ON BATS. [Apr. 7, 



quite I'udimentary (equal to a lowei' incisor, or about J^ of m'), 

 its elements cannot be discriminated, and the tooth has been 

 pushed postero-internally to ni" (text-fig. 46 a) ; but in most 

 species of Artibeus m^ is entirely wanting. — (5) As a consequence 

 of the larger size and posterior position of m^ in Uroderma, cusp 5 

 of m" is considerably more labial in position (text-fig. 44 a) ; in 

 Artibeus the cusp has moved so far towards the lingual side as 

 to occupy, precisely or very nearly, the middle of the posterior 

 margin of the tooth (text-fig. 46 a). — (6) Cusp 2 of m^ is in 

 Uroderma represented by a low subacutely pointed tubercle near 



Text-fig. 47. Text-fig. 48. 



Text-fig. 4^7.— Uroderma tJiomasi, $ ad. Bellavista, Bolivia. Type, B.M. 1.2.1.37. 

 Front view of lower incisors and canines. X f- 



Text-fig. 48. — Artibeus jamaicensis Uturattis, ? ad. Villa Rica, Paraguay. 



U.S. N. M. 105587. 



Front view of lower incisors and canines. X y. 



the front end of the tooth and close to the lingual side of cusp 4 

 (text-fig. 44 b) ; in Artibeus cusp 2 is very strongly developed, 

 rising as a high slender cone near the middle of the lingual 

 margin of m^ (text-fig. 46 b).— (7) In accordance with the less 

 reduced size of m^, also m, in Uroderma is proportionately larger, 

 equal to ^-| of m^ (text-fig. 44 b); in Artibeus m.^ is ^-yL the 

 size of m^, or, in more than half the number of species, entirely 

 wanting. 



External characters. — The lateral margin of the horseshoe, at 

 level with nostrils, is turned upwards so as to form a conspicuous 

 fold ; when pressed downward to the muzzle this fold takes 

 the shape of a small, rounded lobe, slightly projecting beyond 

 the rest of the lateral margin. In several species of Artibeus 

 {A. planirostris, jamaicensis, etc.) there is a similar, though rather 

 less pronounced folding of the lateral margin of the horseshoe. 

 The difference between Uroderma and Artibeus in this respect is, 

 therefore, only one of degree. 



The wing-structure is very similar to that of Artibeus; the 

 fifth metacarpal averages a trifle shorter than the third, whereas 

 in all species oi Artibeus it is generally a trifle longer than the 

 third. How closely in all other respects the wing-structure of 



Uroderma resembles that of Artibeus may be seen by reference to 

 the wing-indices on p. 310 (compare, for instance, the indices of 



Uroderma with those of A. rosenbergi). 



