FRESHWATER CRAYKISUES OK Al'STRAl.lA. 145 



and beautiful drawings made by M.v. W. G. Biowuiiig under my 

 direction, illustrating the forms and chief varieties of all the 

 known species, by arranging these species in systematic genera 

 according to their structural affinities, by recording, as far as is 

 known, their geographical distribution, and by indicating the 

 light which they throw upon the geograpliieal problems of 

 Australia, it is hoped that a secure foundation may be laid 

 on which local naturalists can build. In this memoir, only 

 the Freshwater forms are dealt with, comprising the genera 

 Astasopsis, t'hcer.y.jis, and Parachceraps, the treatment of the land- 

 Crayfishes of Australia included in the genus Ewfceus being 

 postponed to a future paper. These land-Crayfishes, which are 

 a highly specialised group, probably derived from the freshwater 

 form Parachceraps hicarinaius, are confined, in their distribution 

 to the Victorian Highlands, Gijppsland, ancLJTasmania. 



The material on which this} memoir is fou^rdf)^* .^as in part 

 collected by myself in Tasmania and Australia during my visit 

 to those countries in the years 1907-8, but by far the largest 

 number of specimens are derived from the very fine collection 

 belonging to the Melbourne Museum, which Professor Baldwin 

 Spencer entrusted to me for description. This collection, which 

 has been gradually accumulated during twenty years by the 

 efforts of a number of Victorian naturalists, especially Mr. 

 Kershaw and Mr-. Fulton, is particularly i-epresentative of 

 Victorian fofms, though specimens from other States are not 

 altogether absent. I have been able to supplement this 

 collection by specimens from New South Wales, through the 

 kindness of Professor Haswell, from Western Australia, thi'ougi 

 Mr. Woodward of Perth, and from New Guinea, through 

 Dr. Gestro of Genoa. 



It appears probable that as the popiilation of Australia 

 inereasas, the Freshwater Crayfishes might assume as much 

 importance, as an article of food, as the lobster in America or 

 England. There is no true lobster in the Austi'alian seas; its 

 place is taken by a form allied to our Rock Lobster {Palinurus), 

 which is altogether inferior as an article of diet. In the first 

 place, it possesses no large claws and the flesh is altogether coarser 

 than in the lobster. Tlie Australian Freshwater Ci'ayfishes, on 

 the other liaud, are, on the whole, superior in flavour and texture 

 to our marine lobsters. Several of the forms, notably Astacopsis 

 serraius of the Murray Kiver a,nd A. franklinli of the North -Tas- 

 manian streams, attain a very large size indeed (Pis. XIV., XVI.), 

 the body reaching a foot in length and the whole animal weighing 

 as much as eight or nine pounds, thus rivalling a fine lobster. 

 These animals not very frequently reach the Melbourne market, 

 and the Tasmanian Crayfish, which is the finest of all, is, I 

 believe, only occasionally caught and eaten by settlers in the 

 bush or a few prospectors. The labour of obtaining these large 

 Crayfishes, for they are not very abundant, has hitherto prevented 

 their becoming an article of commerce. It would pr-obably be 



Pfioc. ZooL. Soc— 1912. No. X. 10 



