324 THE FIJI IS. AND SOUTH AND WEST AUSTRALIA chap. 



their possession of the typical heavy Placostylus (5 sp.) of the 

 former, and the lighter and more elegant Charis (2 sp.) of the 

 latter. There are 4 Papuina^ and Partula is abundant (18 sp.), 

 but there is no evidence at present that the carnivorous genera 

 or the Melanopsis and Isidora of New Caledonia occur. 



The Fiji Is.^ by the possession of 14 Placostylus of the Charis 

 section, which is entirely absent from the adjacent Tonga group, 

 form the eastern limit of the province. There appears to be only 

 a single Partula^ but the Polynesian element, especially as seen 

 in Navicella (8 sp.), Neritina (20 sp.), Helicina (11 sp.), and 

 Omphalotropis (11 sp.), is very strong. The Microcystis (9 sp.) 

 and Trochomorpha (14 sp.) are also of a Polynesian type. 



(2) The Australian Sub-region includes the whole of 

 Australia (with the exception of the Queensland province) and 

 Tasmania, with New Zealand and the off-lying islands. The 

 fauna, from the prevalence of desert, is scanty, especially in 

 genera. Land operculates are almost entirely wanting. Limax 

 is not indigenous, though several species have become natural- 

 ised. The bulk of the fresh-water species belong to Isidora^ and 

 it is doubtful whether Physa occurs at all. Unio has a few 

 species, and also Vivipara^ but neither Anodonta nor Ampullaria 

 occur. ,. There are a few Melania and Neritina. 



Tropical South Australia. — The Mollusca are scanty, and 

 occur chiefly in the neighbourhood of the rivers, the soil being 

 arid, with no shelter either of trees or rocks. Fresh-water 

 species predominate, and the rich land fauna of Queensland is 

 totally wanting. There are no land operculates, 6 Hadra^ 1 

 Bulimus (?), 1 Stenogyra. 



]yest Australia. — Owing to the deserts which bound it, the 

 Mollusca are very isolated, only one species being common with 

 N., S., and E. Australia. The chief characteristics are Liparus, 

 a form intermediate between Helix and Bulimus^ and, among the 

 Helices, the group Rhagada. There are no slugs, no carnivorous 

 snails, and only three land operculates. 



Land Mollusca of West Australia 



Lamprocystis . 



1 Gonostoma 



. 2 



Hadra . . 



. 5 



Cyclophorus 



2 



Hyalinia . . 



1 Trachia . . 



. 3 



Liparus . . 



. 10 



Helicina 



1 



Patula' . . . 



7 Xeropliila . 



. 1 



Pupa . . 



. 4 







Cbloritis . . 



2 Rhagada . 



. 8 



Succiuea . 



. 3 







