146 A NATURALIST IN TASMANIA ch. 



characterized by the absence of all the freshwater 

 fish except Eels and the genus Galaxias, and by 

 the absence of the Land Crab (Engaeus), The 

 second region is the low-lying strip of the north 

 coast composed of various geological formations 

 with eruptive basalts and granites, and a large 

 Tertiary Estuarine deposit ; this area is character- 

 ized by the absence of Anaspides and Phreatoicus, 

 and by the presence of the large freshwater 

 Crayfish Astacopsis franhlinii and of the fresh- 

 water fishes Aphritis, Prototroctes, and Gadopsis 

 (Black-fish). 



Finally we have the West Coast Region with its 

 mountains of Archaean and Palaeozoic rocks especi- 

 ally characterized by their peculiar vegetation, by 

 the entire absence of the Black-fish and the Flat- 

 head {Aphntis),d^ivdi of the Cucumber Herring {Proto- 

 troctes) except in the north-western corner. The 

 West Coast Region, both in its physical and f aunistic 

 characters is more closely allied to the northern area 

 than to the greenstone plateau. Thus the large 

 Astacopsis is found in many of the west coast rivers, 

 and so is the Cucumber Herring, while there are bits 

 of beech forest on the north-east coast, e.g. on the 

 road from Evandale to St. Helen's, which vie in 

 luxuriance with the true west coast forests. How- 

 ever, the botanical characters of the west coast are 

 sufficiently distinct to warrant the separation of 

 this area from the others, and doubtless a better 

 acquaintance with its fauna would bring to light 

 other differences. 



