222 On an Extinct Fruit-Bat from the Mascarenes. 



m. 2 13j inside m- 2 9'2 ; zygomatic breadth (approximate) 27 ; 

 kast interorbitaTbreadth 7*8 ; the dimensions of tlie struc- 

 ture behind postorbital process cannot be taken ; greatest 

 breadth of brain-case 15 ; occipital depth 11 ; mandible 40-6 ; 

 maxillary tooth-row exclusive of incisors (alveoli) 20-1 ; 

 mandibular tooth-row exclusive of incisors (alveoli) 22-3. 



Teeth. — With the longitudinal grooving characteristic of 

 the genus Pteropus, very strongly^ developed, somewhat 

 large and heavy for the size of the animal ; canines long and 

 sharp, both above and below, with unusually acute and 

 prominent postero-internal basal ledges, those of the maxillary 

 in particular ; first upper premolars very minute, but would 

 have been still persistent in the type and standing in the 

 tooth-vow. 



Measurements. — The sizes of the upper incisors and second 

 upper molars are omitted, as these teeth are wanting in the 

 specimen. Vertical length of upper canine 7-5 mm.; hori- 

 zontal length of upper canine 3*5 ; horizontal length of p^ 

 3-8, width 2-3 ; horizontal length of p^ 3*8, width 3 ; 

 liorizontal length of mj- 4*1, width 2-1. Lower teeth — com- 

 bined breadth of incisors — ? ; height of canine (from basal 

 ledge behind) 5 ; horizontal length of anterior premolar 2 ; 

 of p73 3*8, width 2-1 ; horizontal length of p. 4 3*5 ; of m. 1 4'3, 

 width 2 ; horizontal len gth o f penultimate molar 3, width 

 1-8 ; horizontal length of mTS 1*5, width 1-4. 



Locality. — Round Island, North-east Mauritius. 



As compared with the now existing Pteropi of the 

 Mascarenes, this species occupies a place intermediate between 

 Pteropus vampyrus and Pt. rodricensis, in size only, the 

 dentition being' typical of Pteropus, whereas the two above 

 species fall into the subgenus Spectrum. The only other 

 fruit-bat occurring in the Mascarenes is Pt. ruhricollis, and 

 this has been placed by iJatschie in his subgenus Serico- 

 nycteris. A great analogy, in fact, exists between the dentition 

 of Pt. mascarinus and those species of Pteropus {tonganus, 

 Gouldii, and conspicillotus) inhabiting Australia and the 

 islands of the Pacitic Ocean. 



The limb-bones call tor no special description, the most 

 perfect specimen being the right femur, which measures 

 40 mm. 



Since the above was written a few additional bones referable 

 to this new species, and rei)resenting two younger individuals, 

 have been received. Their fragmentary condition has, 

 however, failed to add any additional particulars to the above 

 description of this interesting and lost species. 



