THE FAMILIES AND GENERA OF BATS. 47 



Occiput so much deflected that alveolar line projected backward passes 



through or above root of zygoma. 



Posterior portion of occiput not distinctly elongated and tubular. 



Audital bulla with annular meatus ; first lower molar scarcely 



longer than second Rousettus, p. 54. 



Audital bulla with tubular meatus ; first lower molar nearly as 



long as second and third together Pterocyon, p. 55. 



Posterior portion of occiput distinctly elongated and tubular. 



2-2 

 Incisors =-=. 



Canines with well-developed secondary cusps-Pteralopex, p. 60. 

 Canines without secondary cusps. 



First and second lower molars with broad, flat postero- 

 internal heel in addition to the two longitudinal 



ridges Acerdon, p. 59. 



First and second lower molars without postero-internal 



heel. 



Upper molariform teeth (pro 4 m 1 and m 2 ) subquad- 



rate in outline, essentially alike in form ; crown 



diameter of inner mandibular incisor about I that 



of outer . Desm,alopex, p. 60. 



Upper molariform teeth (pm 4 m 1 and m 2 ) not sub- 

 quadrate, differing notably from each other in form ; 

 crown diameter of inner mandibular incisor about 

 i that of outer___' Pteropus, p. 56. 



Incisors less than -^ . 



Lower incisors 2-2 ; upper incisors wide apart Boneia, p. 61. 



Lower incisors 1-1 ; upper incisors close together. 



Upper incisors 1-1 ; cheek teeth normal Doosonia, p. 63. 



Upper incisors 2-2 ; cheek teeth with rounded crowns and 

 broad low ridges Styloctenium, p. 62. 



Genus CYNOPTERUS F. Cuvier. 



1825. Cynopterus F. Cuvier, Des Dents des Mammiferes, p. 248 (Pteropus 

 marginatus Geoflvoy =Vespertilio sphinx Vahl). 



1828. Pachysoma Is. Geoffkoy, Diet. Class. Hist. Nat., XIV, p. 703, Septem- 

 ber, 1828. (Pteropus melanocephalus, P. titthwcheilus, Pachysoma 

 diardii, P. duvaucelii, P. brevicaudatum) . Not Pachysoma MacLeay 

 1821. 



1878. Cynopterus Dobson, Catal. Chiropt. Brit. Mus., p. 80 (part; mar- 

 ginatus, scherzeri, brachysvma). 



1899. Cynopterus Matschie, Flederm. des Berliner Mus. fiir Naturk., p. 74 

 (subgenus). „_ 



Type-species. — Pteropus marginatus Geoff roy =Vespertilio sphinx 

 Vahl. 



Geographic distribution. — India and the Malay region, east to the 

 Philippine Islands. 



Number of forms. — As here restricted, the genus Cynopterus con- 

 tains about a dozen known forms,, most of them closely related to C. 

 sphinx. 



