I'TEROPUS COGNATUS. 251 



from each other in minor details of dentition, colour, and size. 

 Ft. chryaojyr actus (Amboina group) is on the whole rather closely 

 allied to tho largo western Solomon Island species. As yet no 

 form of this group is known from New Guinea. 



Affinities of group.~Q\o&e\y allied to the Pt. hmhocensis group 

 {infra), with which it accords in the shortening of the rostrum (a 

 character still further developed in the hmhocensis group), reduced 

 size of ffig, tendency in certain species to reduction also of m^, 

 distribution of fur (tibia clothed above), and development of neck- 

 tufts in males ; Pt. coynatus, in colour apparently the least 

 specialized form of the group, shows, as mentioned above, 

 externally no small resemblance to Pt. hmhocensis. The rayneri 

 group differs from Pt. hmhocensis chiefly in the lesser shortening of 

 the rostrum, the less constant and less conspicuous reduction of m^, 

 and the perfectly normal i^. 



42. Pteropus cognatus, K. And. 

 Ptcropus rayneri (pt.), Dobson, Cat. Chir. B. M. p. 33. 



Pteropus rayneri (pt.), Gray, Cat. Monk. SfC. p. 108 (1870 : 

 San Christoviil ; nee Guadalcanar) ; Dohson, I. s. c. (1878 : 

 San Ciiristoval) ; Trouessart, Rev. 4" Mag. Zool. (3) vi. p. 204 

 (1879: San Christoval) ; id., Cat. Mamm. i. p. 78 (1897: San 

 Ohristoval). 



rtei-opus (Spectrum) rayneri (pt.), Trouessart, Cat. Mamm., SuppL 

 p. 51 (1904: San Christoval). 



Pteropus cognatus, K. Andersen, Ann. <^- Mag. N. II. (8) ii. p. 365 

 (1 Oct. 1908: San Christoval). 



Diagnosis. — Rostrum short and broad ; m^ conspicuously reduced 

 in size. Ears moderate, exposed, narrowly rounded off at tip. 

 Tibia clothed above. Dark brownish above and beneath (rump 

 not differing from back) with cinnamon or russet mantle. Forearm 

 at least \'2\ mm. (no jierfectly adult specimens seen). Hah. San 

 Christoval, E. Solomon Is. 



/SYlm^Z.— Chief characters (compared with the typical Pteropine 

 skull) : Rostrum short and broad, front of orbit vertically above 

 posterior half of p' ; mandible heavier posteriorly : coronoid height 

 (26 mm.) subequal to length of lower tooth-row, c-va^ (25-5 mm.). 



Teeth. — m^ considerably reduced, little more than half the size 

 of Pj ; also m- slightly smaller than in Pt. liypomelanus. Cingulum 

 of upper and lower canines stronger than in Pt. hyijomelanns, forming 

 a well-defined rather broad ledge at inner base of teeth. Other 

 teeth scarcely differing, neither in form nor in size, from those of 

 Pt. Tiyj^omdanun. 



Fur. — Rather short, adpressed on back ; approximate length of 

 hairs, back 11-12, mantle 14, belly 14 mm. Tibia thickly clothed 

 above for proximal two-thirds or three-fourths, underside of tibia 

 hairy for proximal half. 



Cohur. — (^ imm. skin, December, type of species: General 



