60 BULLETIN 5*7, UNITED STATES NATIONAL MUSEUM. 



DESMALOPEX, new genus. 



Type-species. — Pteropus leucopterus Temminck (as understood by 

 Dobf;on, Catal. Chiropt. Brit. Mus., p. 32. 1878). 



Geographical distribution. — Philippine Islands. 



Number of forms. — The type is the only species known. 



Characters. — Like Pteropus; but skull with broader rostrum and 

 palate, orbits directed slightly more upward, and teeth showing sev- 

 eral peculiarities that suggest Pteralopex. Upper incisors subequal, 

 distinctly larger than in Pteropus, the cross section of the crown 

 nearly one-third that of canine, the cingulum produced into a notice- 

 able shelf posteriorly. Lower incisors very unequal, the crown area 

 of the outer nearly one-half that of canine, that of the inner scarcely 

 more than one-half as great. Canines not peculiar, the upper with- 

 out secondary cusps. Small upper premolar well developed, not 

 deciduous, its diameter nearly half that of upper incisor, its crown 

 flat. Small lower premolar relatively larger than in Pteropus, but 

 smaller than in Pteralopex, its outer edge raised but not distinctly 

 cuspidate. The remaining premolars, both above and below, agree 

 with those of Pteropus, except that pm 3 shows no trace of cusp on 

 inner side. Molars, both above and below, subquadrate in outline, 

 the length of the crown never conspicuously greater than the width 

 (to 3 and to * not elongated as in Pteropus) . In the maxillary teeth 

 the cusps are like those of Pteropus except that they are higher rel- 

 atively to length of crown. Lower molars peculiar in that the 

 ridges of to x and m 2 are each divided into two low but distinct 

 rounded cusps. The quadritubercular form resulting from this is 

 very noticeable in to a , less so in to 2 . Third lower molar as in 

 Pteropus. 



Species examined. — Desmalopex leucopterus (Temminck). 



Remarks. — This genus is intermediate between Pteropus and Pte- 

 ralopex, though nearer the former. In the broadened rostrum and 

 slightly upturned • orbits the skull distinctly suggests Pteralopex, 

 while the same tendency is shown by the form and relative size of the 

 incisors, the well-developed small upper premolar, the squarish out- 

 line of the molars, and the extra cusps of to l and m 2 . Externally 

 there are no characters worthy of note. 



Genus PTERALOPEX Thomas. 



1888. Pteralopex Thomas, Ann. and Mag. Nat. Hist., Oth ser., I, p. 155, 



February, 1888. (atrata.) 

 1899. Pteralopex Matschie, Flederm. des Berliner Mus. fur Naturk., p. 11. 



(Subgenus of Pteropus.) 



Type-species. — Pteralopex atrata Thomas. 

 Geographic distribution. — Solomon Islands. 



Number of forms. — Only the type species has been thus far dis- 

 covered. 



