84 



CKITICAL OBSERVATIONS ON RECENT CONTRIBU- 

 TIONS TO OUR KNOWLEDGE OF THE FRESH 

 WATER SHELLS OF TASMANIA. 



Paet I. 



By R. M. Johnston, F.L.S. 



In August, 1875, the Rev. J. E. Tenison-Woods contributed 

 a paper to this Society on the fresh water shells of Tasmania. 

 Prior to this date no systematic attempt had been made to 

 arrange the fresh water shells of this island. It is true that 

 five or six species were actually described in the scattered 

 works of earlier writers, but these isolated observations in 

 foreign works attracted little notice locally ; indeed, without 

 special research and access to a good library of reference it 

 would be impossible for ordinary students to obtain certain 

 guidance on the subject. 



Mr. Woods fully described the shell characters of all the 

 four forms known to him at this time, and from such 

 characters, and from former references by other observers, 

 he determined them to consist of 12 genera and 34 species, 

 all of which, with the exception of five, he considered as new 

 to science. The following is a complete list of the species 

 described by him : — 



Univalves — 



1. Ancylus Cummingianus, Bourg. 



2. Tasmauicus, Ten. Woods. 



3. Limncea Tasmanica, Ten. Woods. 



4. Huonensis, Ten. Woods. 



5. Hobartensis, Ten. Moods. 



G. Launccstoncnsis, Ten. Woods. 



7. Physa aperta, Ten. Woods. 



8. eburnea, Ten. Woods. 



9. mamillata, T'en. Woods. 



10. nitida, Soicerby. 



11. Brunicnsis, Sowerby, 



12. Vandiemenensis, Soioerby. 



13. Huonensis, Te7i. Woods. 



14. Legrandi, Ten. Woods. 



15. Tasmanica, Ten. Woods. 



16. ciliata. Ten. Woods. 



17. Tasmanicola, Ten. Woods. 



18. Huonicola, Ten. Jl oods. 



19. Bythinia Legrandi, Ten. IVoods. 



20. Poutvillensis, Ten. Woods. 



