268 Mr. K. Andersen on new 



alveolus 10 (8"7-9*2), greatest aiitero-posterior diameter of 

 crown 6-2 (5-2-5-7). 



Fur. — Approximate length of hairs, back 20 mm. (12-14: 

 in Pt.atra(a), mantle 30 (18-20), belly 21 (13-15). Tibia 

 and metatarsus densely clothed above ; thinly scattered hairs 

 on phalanges of toes; in Ft. atrata the fur extends backward 

 on proximal three-fourths of tibia, leaving distal fourth of 

 tibia, metatarsus, and phalanges naked save for some thinly 

 spread hairs. Furred area of back broader than in atrata. 



Colour. — Blackish tinged with seal-brown; middle of 

 breast and belly light drab with short concealed seal-brown 

 bases to the hairs. Pt. atrata is practically uniform blackish 

 above and beneath, with no trace of drab on underparts. 



Size. — Probably as Pt. atrata. The type and only speci- 

 men known is slightly immature (evidently very nearly full- 

 grown ; forearm 137 mm., in four adult Pt. atrata 139-143'.')). 

 Type. ? imm. (skin and skull) ; Bougainville, April 1901; 

 collected by A. S. Meek; B.M. 8. 11. 16. 7. 



Remarks. — The discovery of this species is of particular 

 interest, not only because it is a second form of the peculiarly 

 aberrant genus Pteralopex, which was hitherto known from 

 Guadalcanar only, but also, and chiefly, because it links that 

 genus more intimately to Pteropus. Pteralopex anceps possesses 

 all the essential dental characters of Pt. atrata^ some of these 

 quite as highly developed as the eastern species (enlargement 

 of upper incisors and canines, outer lower incisors, and p,, 

 secondary cusp of upper canines, &c.), others decidedly less 

 developed (anterior and posterior basal ledges of raolariform 

 teeth, splitting of outer cusp of p4 and mi), but. at the same 

 time it has preserved more of the dental ciiaracters of an 

 ordinary Pteropus (inner ridges of upper and lower molaiifonn 

 teeth, le.^s excessive shortening of these teethj. So far as 

 the two latter categories of characters are concerned, it shows 

 one of the stages through which the still more highly 

 specialized Pt. atrata must, in all probability, have passed. 

 Externally, in the distribution, quality, and length of the 

 fur, as well as in the colour of the whole of the upper side, it 

 bears a striking resemblance to Pteropus pselaphon (see my 

 paper on the affiaities of Pteralopr-x, Ann. & Mag. Nat. Hist., 

 Feb. 1909, pp. 218-222). 



Hipposiderus dcmissusj sp. n. 

 Diagnosis. — A species of the H. diadema group, allied to 

 H, oc(a-iitis (Guadalcanar), but much smaller, and conspicu- 

 ously paler beneath. Hub. San Christoval, E. Solomop 

 Islands. 



