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IV. The Freshwater Crustacea of Tasmania, with Remarks on their Geographical 

 Distribution. By Geoffrey Watkin Smith, 31. A., F.L.S , Fellow of New College, 

 Oxford. 



(Plates 12-18 and Map.) 



Read 19th November, 1908. 

 Part I.— GENERAL. 



Historical. 



-DURING a six months' stay in Tasmania (October 1907 to March 1908), undertaken 

 at the suggestion and through the assistance of Prof. G. C. Bourne of Oxford, I visited 

 a great number of freshwater localities in the island with the object of making a 

 collection and study of the Crustacea. Tasmania is a particularly favourable place for 

 studying the Australian freshwater fauna, as its highlands are covered with numerous 

 large lakes and tarns, and the country everywhere is watered by large rivers and 

 streams. 



Previous to my visit, the only naturalist who had made a study of the Crustacea was 

 G. M. Thomson, P.L.S. (Proc. Roy. Soc. Tasmania, 1892, p. 51), who confined himself to 

 the Malacostraca from a few localities. Most of the Tasmanian genera are, however, 

 common to Victoria and New South Wales, so that the works of Sars and Sayce (see 

 Systematic Part) have been of great use to me in assigning species to their proper 

 systematic positions. Besides the discovery of several new forms of interest, I believe 

 that my collections are sufficiently thorough and cover a wide enough area to establish 

 clearly not only what are the dominant genera in Tasmanian freshwaters, but also 

 what genera characteristic of other countries are absent. 



In the account of the localities visited and the nature of their Crustacean fauna I 

 confine myself to stating the most important physical characters ; but if the reader is 

 desirous of knowing more about the nature of the country and the means of transit I 

 may refer him to my book, ' A Naturalist in Tasmania' (Clarendon Press). 



Localities ; with their Crustacea. 



Tasmania falls naturally into three chief regions : — (1) The Greenstone Plateau. The 

 plateau itself, formed of igneous dolerite or diabase, occupies the centre of the island, 

 the various large lakes being situated on the tableland at an elevation of 2000-3000 ft. 

 above sea-level. The diabase plateau is everywhere flanked by Permo-Carboniferous 

 sand- and mud-stones, beneath which the diabase was originally thrust upwards. To 



SECOND SERIES. — ZOOLOGY, VOL. XI. 9 



