So PETTARD : ON FRESHWATER SHELLS OF TASMANIA. 



LIST OF THE FRESHWATER SHELLS OF TASMANL\. 

 By W. F. PETTARD. 



In a paper by the Rev. Tennison Woods, read before the 

 Royal Society of Tasmania on the 9th of August, 1875, the 

 author gives a Hst of the Freshv/ater Shells of this Island, including 

 the description of many unrecorded species that had been dis- 

 covered from time to time, but as several of that gentleman's 

 names will have to be replaced by the prior ones given to the 

 same species by Mr. Brazier in the ' Proceedings of the Linnean 

 Society of New South Wales,' and as some very interesting new 

 forms have more recently been discovered by Mr. R. M. Johnston 

 and myself in the northern part of the Island, I undertake the 

 present revision of the Freshwater Shells of Tasmania, a^ well as 

 to point out several errors that the author has fallen into, which, 

 if my observations are correct, are the more excusable considering 

 that the reverend gentleman had but scant acquaintance with 

 the great majority of the species enumerated in their living state, 

 and v,'as therefore unable to observe the variations in form and 

 colouration and to some extent size a great number of our species 

 are hable in more or less favourable localities for their life. By the 

 present revision there are enumerated in all 36 species of the 

 Freshwater Molluscan Fauna as at present known, but as the 

 greater portion of the Island remains unexamined, a much further 

 increase in the number of species may be confidently anticipated. 

 They are distributed in the following genera :—Z;7;/;/6f«, 3; Fhysa, 

 9; Plaiwrbis, 3; Ancyliis, 3; Giindlachia, i; Pomiatopsis, i; 

 Assimifiea, 1; Ampidlaria, i; Valvata, 1; Bithynia, 7; Amiiicola, 

 i; Lhiio, i; Cyclas, i; Fisidhim, 2. 



Although the general character of the great majority is very 

 distinct from those at present known from the mainland of 

 Australia, nevertheless there are several that have a very close 

 resemblance, and it is quite probable are but varieties, or at least 



J.C, ii., Mar., 1S79 



