62 BULLETIN 57, UNITED STATES NATIONAL MUSEUM. 



sor very small, the inner extremity of the premaxillary projecting 

 beside it and appearing at first sight like a second tooth. Lower inci- 

 sors as in Pteropus, but disproportion in size between outer and 

 inner more evident. Canines not peculiar, except that the lower 

 are more strongly curved backward and outward than in the related 

 genera. Small upper premolar (pm 2 ) apparently permanent, con- 

 siderably larger than in Pteropus. Except for the greater size of 

 pm 2 , the two anterior cheek teeth in each jaw are essentially as in 

 Pteropus. The three posterior above (pm 4 , m 1 , and m 2 ) and the 

 four posterior below pm 4 , m 15 m „ and m 3 ) are remarkable for their 

 very flat crowns, with very low, though sharp, peripheral ridges. The 

 crown of m 1 and of m 1 is crossed by a distinct transverse ridge be- 

 tween the two very rudimentary cusps. General outline of crowns 

 as in Pteropus. Skull differing from that of Pteropus in the slightly 

 greater deflection of the brain case (alveolar line projected backward 

 passes slightly above root of zygoma) and in the low, weak posterior 

 section of mandible, the coronoid process forming an unusually slight 

 angle with the ramus. External characters as in Pteropus, except for 

 the presence of a well-developed tail projecting distinctly beyond 

 inter femoral membrane. Index finger with claw. 



Species examined. — Boneia bidens Jentink and B. menadensis 

 Thomas. 



Genus STYLOCTENIUM Matschie. 



1878. Pteropus Dobsok, Catal. Cbiropt Brit. Mus., p. 15 (part). 



1899. St uloctenium Matschie, Flederm. des Berliner Mus. fiir Naturk., p. 33. 



(wallacei.) 



Type-species. — Pteropus wallacei Gray. 



Geographic distribution. — Celebes. 



Number of forms. — One, the type species." 



Characters. — Like Pteropus, but with only 1-1 lower incisors and 

 2-2 lower molars ; cheek teeth subterete in outline and with smoothly 

 rounded crowns. Dental formula: 



-2 3. 1. -234 56- .2-2 1-1 3-3 2-2 



- 2 -. 1. - 2 3 i 5 6 - 1 1=1' c l=l^ m 3=3' m 2=2 =3 °- 



Incisors both above and below terete, very straight, the crowns 

 abruptly pointed and scarcely differentiated from shafts. Canines 

 as in Pteropus, but rather short and thick. Small upper premolar 

 (pm 2 ) deciduous, similar in size and form to that of Pteropus. 

 Other anterior cheek teeth not peculiar, though rather less pointed 

 than in Pteropus. Posterior three teeth in each jaw (pm *,m 1 ,m 2 , 

 and pm 4 , to 1; m 2 ) , with crowns nearly circular in outline and 'with 

 evenly rounded surface, the cusps and ridges, though normal in posi- 

 tion, so flattened and broadened as to be scarcely noticeable. Skull 



