172 riEEOPL'S MARIANXTJS GROUP, 



B. TuE Pteropis mariaxxv.s group. 



Species. — Eight, Ft. iJeleiuensis, yapensis, ualaaus, mariannus, 

 loochoensis, vanikorensis, tongamts, and r/cddiei. 



Range. — Polynesia (so far as inhabited by the geuiis), extending 

 north-west to South Liu-kin Islands. 



General characters.- — Skull and dentition unmodified Pteropine ; 

 posterior basal ledges of premolars slightly more developed than in 

 Ft. Inipomelanus. General shape of ears and distribution of fur as 

 in Pi. h)/pomelanus ; ears moderate, broad, tip rounded off; fur 

 short, adpressed on back ; tibia naked above. Colour pattern 

 remarkably constant : in nearly all species, mantle light yellowish 

 strongly contrasting with blackish or dark brownish back, muzzle, 

 and underparts ; dark colour often sprinkled with greyish or 

 whitish, especially on underside. Sexual differentiation inconsi- 

 derable : males without glandular neck-tufts, but generally with 

 rather heavier canines and fur of mantle more rigid, oily, and 

 uniform buffy (in females softer, more spreading, and with concealed 

 brownish bases to the hairs). Size generally moderate or rather 

 small (forearm 113-154 mm.). 



Differentiation of species. — The eight species are separable into 

 two sections : a series of relatively smaller-eyed North Pacific forms 

 (/*<. pelewensis, yapensis, ualanus, mariannus, and loochoensis), dis- 

 tributed over the Pelew, Caroline (two species), Marianne, and South 

 Liu-kiu islands ; and a series of relatively larger-eyed South Pacific 

 forms {Ft. vanil-orensis, tonf/anus, and geddiei), ranging over the Santa 

 Cruz, New Hebrides, New Caledonia, Fiji, Tonga, and Samoa islands. 

 Ft. peleiuensis is a peculiarly small and small-toothed species, in the 

 colour of the fur rather closely approaching Ft. admiralitatum. The 

 four other North Pacific species are closely interrelated ; from 

 Ft. peleivensis they differ chiefly in their larger size, from each other 

 in the size of the teeth and length of the fur ; the teeth are smallest 

 in Ft. ualanus (East Carolines), heavier in Ft. yapensis (West Caro- 

 lines) and Ft loochoensis, rather heavier still in Ft. mariannus ; the 

 fur is longer than usual in the extreme north-western species, 

 Ft. loochoensis. — Also the three species of the South Pacific section 

 are closely related. Ft. vanikorensis (known from Vanikoro only) 

 is chiefly characterized by its shorter. Ft. tonganus (P'iji, Tonga, 

 and Samoa islands) by its longer wings ; Ft. geddiei (Now Hebrides 

 and New Caledonia) is the largest form of the group. 



Affinities of group. — The Ft. mariannus replaces the Ft. hypo- 

 melanus group in Polynesia ; tliere can be little doubt that it is a 

 Polynesian modification of the hypomelanus type. Taken as a whole 

 it differs from this latter only in characters of trivial importance : 

 the slightly heavier posterior basal ledges of the premolars and the 

 style of colour. The former character indicates scarcely more than 

 a slight difference of degree ; the style of colour is closely approached 

 by a species of the hypomelanus group, Ft. admiralitatum ; and both 

 characters are less conspicuous or, as it were, less definitely fixed 

 in the species which geographically are neighbours to the area of 



