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 (pm 4 m 1 and m 2 ) subquad- 
rate in outline, essentially alike in form ; crown 
diameter of inner mandibular incisor about \ that 
of outer Desmalopex, 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 
| that of outer Pteropus, p. 56. 
* . 2-2 
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 Dobsonia, 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 
margvnatus Geoflroy—Vespertilio sphinx Vahl). 
1828. Pachysoma Is. Geoffroy, Diet. Class. Hist. Nat., XIV, p. 703, Septem- 
ber, 1828. ( Pteropus melanocephalus, P. titttuecheilus, P achy soma 
diardii, P. duvaucelii, P. brevicaudatum ) . Not Pachysoma MacLeay 
1821. 
1878. Cynopterus Dobson, Catal. Chiropt. Brit. Mus., p. 80 (part; mar- 
ginatus, scherzeri, br achy soma) . 
1899. Cynopterus Matschie, Flederm. des Berliner Mus. fur Naturk., p. 74 
( subgenus ) . 
Type-species. — Pteropus marginatus Geofiroy—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. 
