280 rxERorus xawaiexsis. 



I. The Pteropvs samoexsis group. 



Species. — Pt. nawaiensis, samoensis, nnetianus. 



Manrfe. — South Polynesia : New Hebrides, Fijis, and Samoas. 



General characters (compare ng. 14, p. 289, skull and dentition 

 of Pt. anetianus). — Hostrum much shortened, coronoid high and 

 steep. Posterior basal ledges of cheek-teeth strongly differentiated, 

 in one species continued as a basal ledge on inner side of lower 

 cheek-teeth ; i.^ and pj larger than usual. Ears small ; intert'emoral 

 practically undeveloped in centre; fur rich, sometimes unusually 

 long and spreading; tibia always clothed above. Colour dark 

 brownish above and beneath, sprinkled with longer pale-coloured 

 hairs; mantle tawny or huffy. Males without glandular neck-tufts. 

 Size moderate (forearm 124-145 mm.). 



Specific differentiation. — In dentition these three Polynesian 

 species mai'k three progressive stages of specialization : in all, the 

 posterior ledges of the cheek-teeth are strongly developed, though 

 still more so in samohisis (Samoas) and anetianus (New Hebrides) 

 than in nawaiensis (Fijis) ; in nawaiensis i^ is rather larger, in 

 samoensis and anetianus much larger than usual in the genus ; in 

 nawaiensis p, is approximately normal, in samoensis and anetianus 

 much enlarged ; in yiawaiensis there is no trace of a lingual ledge 

 in the lower cheek-teeth, in samoensis the posterior basal ledge 

 is sometimes continued forward along the lingual face of p^ and m^ 

 as an obsolescent rim, in anetianus this rim, in p^, m,, and m^, has 

 developed into a broad, well-defined ledge, a character unique in the 

 genus (but reoccurring in Acerodon). 



Affinities of rp-otip. — Probably the South Polynesian representa- 

 tive of the Pt. lomhocensis group, with the typical species of which 

 (Pt. lomhocensis and solitarius) it accords in all important cranial 

 characters, the heavy dentition, the distribution of the fur, and 

 general pattern of colour; a beginning enlargement of p^ is already 

 seen in one species of the lojnbocensis group {Pt. mo/ossinus), a 

 strong development of the posterior basal ledges of the lower 

 cheek-teeth in another species of the same group (Pt. rodricensis), 

 and a pronounced reduction of the ears and lengthening of the fur 

 in both of these species. The two related groups have followed 

 different lines of specialization : in the lomhocensis type nig, m'", and 

 ij are reduced ; in the samoensis type these teeth are normal, but i^ 

 and Pj enlarged and the basal ledges of the cheek-teeth unusually 

 strong. 



52. Pteropus nawaiensis, Grai/. 

 Pteropus samoensis (pt.), Dobson, Cat. Chir. E. M. p. 35. 



Pierijpus nawaiensis, Grai/, Cat. Monk. ^-c. p. 107 (1870 : Nauai 



& ()valau, Fiji Is.). 

 Pteropus vitiensis, Grar/, Cat. 3Ionk. S)C. p. 109 (1870 : Ovnlau, 



Fiji Is.). 

 Pteropus samoensis [nee Peak), Dobson, I. s. c. (pt.) (1878 : Ovalnu ; 



