322 



SOLOMON IS. AND QUEENSLAND 



CHAP. 



Hebrides, New Caledonia, and the Viti Is. is the occurrence of 

 Placostylus (16 sp.). It is very remarkable that this genus 

 should occur in the Solomon Is. and not in New Ireland. The 

 occurrence of Streptaxis^ if authentic, is very noteworthy, the 

 nearest species being from the Philippines. 



Land and Fresh-ivater Mollusca of the Solomon Islands 



(h') The Queensland Province. — The strip of coast-line from 

 Cape York to the Clarence R. stands apart from the rest of 

 Australia, and is closely connected ^vith New Guinea. There 

 can be little doubt that it has been colonised from the latter 

 country, since an elevation of even 10 fathoms would create 

 (see map) a wide bridge between the two. Many of the genera 

 are quite strange to the rest of Australia. Land opercuiates are 

 abundant, and of a Papuan type. Several of the characteristic 

 Papuan genera of Helix (^Papuina^ Chlointis^ Planispira^ occur, 



Fig. 214. — Characteristic Aus- 

 tralian Helices: A, H. 

 {Hadj'ci) pomum Pfr. ; B, 

 H. {Thej'sites) richmon- 

 diana Pfr. x §. 



while Hadra attains its maximum. Panda, Pedinogyra, and 

 Thersites are three remarkable groups in a rich Helix fauna. 

 ParmacocJdea is a peculiar form akin to Helicarion. The carniv- 

 orous Mollusca are represented by Rhytida., Piploiiiphalus (New 

 Caledonia), and Elaea. One species of Janella, a slug peculiar 

 to this region, occurs. The predominant fresh-water genus 

 is Bulinus (^Isidora). Ampullaria and Anodonta are entirely 

 absent from Australia and New Zealand.. 



