326 



POLYNESIA 



CHAP. 



affinity. Otoconcha is peculiar. The fresh-water Mollusca, 

 besides the Isidora characteristic of the sub-region, are partly 

 related to New Caledonia through the occurrence of Melanopsis^ 

 partly to Tasmania through Potamopyrgus^ while the peculiar 

 Latia is possibly akin to Gundlachia (Tasmania). The land 

 operculates number only 5 genera and 14 species in all, excluding 

 a doubtful Diplommatina} 



Lord Howe's ±. is remarkable as containing a Placostylus^ 

 which thus links the island with this province. The remainder 

 of the fauna is Polynesian, w4th the exception of a species 

 (common to the Fijis) of Parmella, a slug akin to Helicarion, 

 Parmacochlea^ and Cystopelta. 



(3) The Polynesian Sub-region includes all the island groups 

 of the central and southern Pacific (except those classified in the 



Papuan and Australian sub-regions), from 

 the Pelews and Carolines in the west to 

 the Marquesas and Paumotus in the east, 

 and from the Tonga group in the south 

 to the Sandwich Is. in the north. It may 

 be subdivided into («) the Polynesian pro- 

 vince proper, and (^) the Hawaiian pro- 

 vince, which includes the Sandwich Is. 

 only. 



(a) The general features of the Poly- 

 nesian province are very similar through- 

 out, although the Mollusca of each island 

 group are in the main peculiar. The species are mostly small 



A 



Fig. 216. — Characteristic 

 Polynesian Mollusca: A, 

 Achatinella vulpina Fer., 

 Sandwich Is. ; B, Par- 

 tula planilabruin Pease, 

 Society Is. 



1 Hedley and Sater, Proc. Linn. Soc. X. S. Wales (2), vii. p. 613. Twenty- 

 one species are ' ' introduced. ' ' 



