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 Charts (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-reg"ionincludesthe whole of Australia 

 (with the exception of the C^ueensland 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 indi- 

 genous, though several species have become naturalised. The 

 bulk of the fresh- water species belong to Isidora, and it is doubt- 

 ful 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. 



West 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 Bidimus, and, 

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

 carnivorous snails, and only three land operculates. 



Land Mollusca of West Australia. 



