PIEKOPUS MEr.AXoPOGOX GROLP. 237 



F. Thk Ptkhopvs melasopogon group. 



Species. — Pt. melanopofjon, aruensis, keyensis, livingstonei. 



Range. — Amboina group (perhaps north-west to Sanghir Islands), 

 Banda Islands, Timor Laut, Key and Aru Islands. One species iu 

 the Malagasy region (Comoros). 



General characters. — Skull typical Pteropine (rostrum somewhat 

 shortened in Ft. keyensis). dentition heavy but not otherwise modi- 

 fied. Palate-ridges normal (54-5 + 3). Ears moderate, broader 

 than usual, not attenuated above ; tip rather blunt, in one species 

 extremely broadly rounded otf. Fur generally very short and 

 closely adpressed ; tibia always naked above. Interfemoral scarceh' 

 developed in centre. Colour varying according to species. Sexual 

 differentiation inconspicuous (canines heavier in males, no neck- 

 tufts). Size large or very large (forearm 162-204 mm.). 



Specific differentiation. — Pt. melannpiogon is peculiar in having 

 the fur of the back exces.sively shortened and restricted to a narrow 

 spinal tract (aged specimens in abraded pelage being nearh' naked 

 on back); in the other species the furred area of the back is of 

 normal breadth. In colour Pt. melanopogon is the most ordinary- 

 looking of the four species : blackish back, chestnut head and 

 collar, golden-buffy underside of body (compare Pt. rufus). Pt. aru- 

 ensis is not essentially different from Pt. melanopogon in the colour 

 of the head, collar and underparts, but the back is glossy silvery 

 whitish (an excessive development of the silvery whitish element 

 in the colour of the back is seen in certain other species of the 

 genus : compare Pt. hypomelamis canus and lepidus with the dark- 

 backed races of the same species, certain individuals of Pt. hypo- 

 melamis tomesi with the normal dark-backed individuals of the 

 same race ; even in Pt. a7-nensis the back is not uniform silvery 

 "whitish, but thinly sprinkled with blackish hairs, reminiscent of 

 the descent of the species from a dark-backed form). Pt, keyensis 

 ia nearly uniform yellowish above and beneath. As already men- 

 tioned above, the ears in the typical species of this group are rather 

 bi'oader than usual with the tip somewhat blunt ; in the only 

 Malagasy representative {Pt. livingstonei) they are so excessively 

 broadened above as to be almost semicircularly rounded off, the fur is 

 longer and harsher than usual, the general colour blackish above and 

 beneath, with or without a remnant of a bright tippet; it is a 

 mountain form, confined to the Comoros, perhaps to one island 

 (Johanna I.). 



Affinities of group. — Judging from the typical Pteropine cha- 

 racters of the skull and dentition, the origin of this group is pro- 

 bably close to that of the foregoing types of the genus. It is not 

 improbable that the rufus, melanotus. and melanopogon groups are 

 rather intimately related (compare the style of colour of Pt. melano- 

 pogon with that of Pt. rufus), the first representing a truly Malagasy, 

 the second an Andaman-Nicobar, the third an Austro-Malayan branch 

 of the same prototype. Pt. melanopogon, keyensis, and aruensis have 

 hitherto been placed in the closest vicinity of Pt. 2W2^unnus and 



