QUEENSLAND AND NEW CALEDONIA 



323 



((?) The Melanesian Province includes those islands on which 

 the remarkable group Placostylus occurs, the metropolis of whose 

 distribution is New Caledonia. These islands are very possibly 

 the remains of what was once a much wider extent of land. 

 A single species of Placostylus occurs both on Lord Howe's I. 

 and in the North I. of New Zealand, but this fact, while highly 

 interesting as indicating a possible former extension of land 

 in a south-easterly direction, is hardly sufficient to bring these 

 islands within the province as now limited. The Solomon Is., 

 although containing Placostylus as far to the west as Faro I., 

 form, as has been already stated, a transitional district to the 

 Papuan province. 



Neiv Caledonia. — The chief features of the Mollusca are the 

 remarkable development of the helicoid carnivorous genera 

 Rhytida (30 sp.) and Piplomphalus (13 sp.), 

 and of Placostylus (45 sp.). There is a stray 

 Papuina^ and a peculiar form Pseudopartida^ 

 but Helix has almost entirely disappeared. 

 Polynesian influence is represented by Micro- 

 cystis (3 sp.), the so-called Patula (13 sp., 

 many of whicli are probably Charopa^^ Torna- 

 tellina (2 sp.), and Helicina (20 sp.). Partula 

 does not reach so far south, but there are two 

 species of Janella. The recurrence of Mel- 

 anopsis (19 sp.), absent from the wdiole Oriental 

 region, is curious, and forms another link with 

 New Zealand. The curious sinistral Limnaea 

 (^Isidora')^ common with Australia and New 

 Zealand, is abundant. 



The New Hebrides link New Caledonia and the Solomons b}; 



Fig. 215. — P/aco.s^v- 

 lus caledonicus 

 Pet., New Cale- 

 donia. X |. 



