G52 



DTAOOPTERUS. 



Dentition (tigs. 53, 54). 



i' i'' c p" p' m' 



X 2 = 28. 



Tho 



'i^2cp, P3P, mjiii^ 

 only genus of Cyuopterine bats with p^ absent (or deciduous). 



Upper and lower incisors as in Ci/noptems. Canines consider- 

 ably longer; upper canine with a deep vertical groove along 

 antero-medial surface, extending nearly from base to tip of crown, 

 no trace of secondary cusp ; cingulum of lower canine thickened at 

 inner edge, but not forming a well-defined cusp, p' absent (no 

 trace of alveoli; all teeth nearly unworn) ; p^ unmodified, p^-m' 

 and p,-mj shorter and much broader than in Cijnopterus, p', m\ 

 Pj, and ni, subsquarish in outline. Outer and inner ridges of pre- 

 molars and molars sharply defined, separated in all cheek-teeth 

 (p' and Pj not excepted), though connected by a prominent trans- 

 verse commissure in p', p', and p^. m' and m, somewhat reduced in 



Fig. 54. — Di^acopterus cpadiceiia (type of species), upper right and lower left 



tooth-row ; right p-', p<. and left pj, pj, viewed from beliiud. 



? (linear). 



size, as compared with corresponding teeth of Cynopteriis, m' being 

 considerably smaller than (in C i/ n.opterus &Mhei\\i;\\ to) p\ m^ slightly 

 smaller than (in Cynoptems equal to or slightly larger than) p^. 

 A rounded surface tubercle in p^ and ni,, larger in the former than 

 in the latter, situated close to, and partly confluent Avith, inner 

 ridges of these teeth (homologous with surface cusp in corresponding 

 teeth of C>/nopteri(s and Ptenochirus). 



Palate-ridges. — Unknown. 



External characters. — Tail and calcar as in Ci/noptcrus. "Wings 

 from base of first phalanx of second toe (in Cj/nojiterus from first 

 too). PoUex much shorter than in Ci/nopterus,thiri and fourth digits 

 considerably, second and fifth slightly longer (owing to a length- 

 ening of the metacarpals of all of these digits and of the proximal 

 phalanx of the third and fourth, whereas the terminal phalanx of 

 the third, fourth, and fifth digits are distinctly shortened ; compare 

 table below : in upper row wing-indices of Di/acop/erus, based on 



