68 A REVISED CENSUS OF THE TASMANIAN FLUVIATILE MOLLUSC A, 



which are interesting, and accompanied by four plates of 

 figures, tolerably well executed and numbered, but strange- 

 ly he has omitted to provide an index to the numbers, so 

 that identification is somewhat difficult. On page 95 of 

 the same volume is a paper on the variability of our 

 Tasmanian Unio, with a folding plate. Op. cit. for 1890 

 he published a list of the whole of the Tasmanian mol- 

 lusca, and in dealing with Physa takes the drastic step 

 of including all the species as synonyms of P. nitida, 

 Sowerby, which is really a council of despair, although he 

 was no doubt partly justified in so doing. He also lumps 

 all the Planorbis together, which is unfortunate. 



LIST OF SPECIES. 

 Family Cycladidce. 



Sp/ui riinn, Scopoli, Intra, ad. Hist, Nat. 1777, p. 397. 



1. macgillivrayi, Smith, Pro. Linn. Soc, 1881, p. 305, pi. 



7, f. 32. Hab.— Great Lake, Waratah, Flinders 

 Island. 



2. tanmanicum, Ten-Woods, Cyclas, P. and P. Roy. Soc 



Tas., 1875, p. 82. Hab. East Coast, near Swansea, 

 type; near Hobart, also Maria Island (Petterd) : 

 differs from the last, in being less round, and with 

 more prominent umbos. PI. IX., f. 1. 



Pisidium, Pfeiffer, Land, Suegn. Moll. Deutsch, 1875, 

 p. 82. 



3. dulvertonensis, Ten. -Woods, P. and P. Hoy. Soc, Tasm. 



1875, p. 82. Type in Tasmanian Museum, Hobart'. 

 Hab. Lake Dulverton. PI. IX., f. 2. , 



4. tasmanicum, Ten. -Woods, P. and P. Roy. Soc, Ta-sm. 



1875, p. 82. Types in Tasmanian Museum, Hobart, 

 Hab. Generally distributed. PI. IX., f. 3. 



Family Unionidce. 



Diplodon, Spix, Test. Fluv. 



5. australis, Lamarck, Unio, Bras. 1827, p. 33; Var. 



legrandi Petterd, P. and P. Roy. Soc. Tasm., 1889, 

 p. 81. Johnston, op. cit., p. 95, two plates; Stimp- 

 son. Pro. Nat. Mus., Smithsonian Inst., xxiii., 1900, 

 p. 891. 



6. mortonicus, Reeve, Unio, Conch. Icon. XVI., 1865, 



f. IIS. Lea, Syn., 1870, p. 43. Stimpson, op. cit, 

 Hab. It is remarkable that the genus in Tasmania 

 is entirelv confined to rivers flowins: into Bass Strait. 



