PETTERD ; ON FRESHWATER SHELLS OF TASMANIA. 8 1 



analogous representatives, as all species having an extended 

 range are liable to vary in a more or less prominent and percep- 

 tible degree. The following are recorded as common both to 

 this Island and the mainland: — Bythinia Huonensis^ B. Dulver- 

 ton'ensis, Pomiatopsis stiiaiula, and a variety of Physa mamillata. 

 It must however be remembered that comparatively little has as 

 yet been done in the Freshwater Molluscan Fauna of Australia, so 

 that it is but premature to draw comparisons as to the relation of 

 the one to the other. 



1. Lymnaea tasmanica, Tennison Woods. Pro. Royal Soc. 

 Tas., 1875. 



Habitat — about Hobart Town. I have little doubt but 

 that this is the well-known European species L. stagnalis, in- 

 troduced with fish ova. 



2. Lymnaea Huonensis, Tennison Woods. Pro. Royal Soc. 

 Tas., 1875. 



L. Launcestonensis, T. Woods. Pro. Royal Soc. Tas., 1875. 



Habitat — Widely distributed both in the northern as well 

 as southerh portions of the colony. I have no hesitation in 

 uniting the two species described by the Rev. Mr. Woods, as 

 it is a very variable shell. In a large series of specimens 

 that I have seen from the north, principally collected near 

 Launceston, both the true typical L. Lmmcestonensis and the 

 Z. Huone7tsis were equally perceptible, as well as intermedi- 

 ate variations. 



3. Lymnaea Hobartonensis, Tennison Woods. Pro. Royal 

 Soc. Tas., 1875. 



Habitat — Near Hobarton. This may be but a variety of 

 the preceding. 



4. Physa aperta, Sowerby. Reeve's Con. Icon., pi. xi., figs. 

 88a-b. 



Habitat — Creeks between Hamilton and New Norfolk, 



J.C, ji., Mar., 1879. C 2 



