216 



aperture in front of tlie columella, wliicli in L. peregra is 

 sliglitly expanded and reflected. 



Amphipeplea papyeacea. 



Reference. — Limncea ijajpyracea — Tate, Trans. Eoy. Soc, S. 

 Aust., vol. iii., p. 103, t. 4, f. 5, 1880. Amphipeplea papyracea 

 — Tato, id., voL iv., p. 140, 1881. 



Among examples of Limncea Huonensis, recently received 

 from Mr. E. M. Johnston, I find three specimens of Amphi- 

 peplea pa'pyracea. The association of the two species may 

 serve to fix the station and locality of this addition to the 

 fauna of Tasmania. 



A. papyracea was originally described from dead shells 

 obtained from a dried pool at Penola, S. Australia, but a 

 year later it was taken alive in the Reedbeds, near Adelaide, 

 and a study of the animal brought about the new generic 

 appellation. 



The species is now known to me, from samples sent by Mr. 

 J. F. Bailey, to inhabit at Merrigum, Victoria. 



Gtjndlachia Petterdi (Johnston). 



This freshwater limpet, originally described from Tasmanian 

 specimens, inhabits the hill-streams of the Mount Lofty 

 Eange, near Adelaide. 



These are the first records of continental species of aquatic 

 pulmonate snails living in Tasmania, and it is surprising 

 that no other specific points of contact have been recognised. 

 As regards the land snails, whose means of dispersal are 

 limited, the distribution of whose sj^ecies is so restricted, and 

 correlatively presenting constant characters so much so that 

 they are valuable factors in defining zoological provinces, 

 there are seven or nine species in common between Tasmania 

 and Australia. (See Tate, Trans. Eoy. Soc, S. Aust., vol. iv., 

 p. 73, 1881.) On the other hand, the aquatic pulmonate 

 snails are in comparison easily dispersed, and their species 

 exhibit great morphological variability, so much so that, as 

 regards the commoner sorts, each hydrographic basin has its 

 own races. There is, therefore, much reason to anticipate a 

 larger community of aquatic species between Australia and 

 Tasmania than we have, at present, knowledge of. 



My personal experience of the limits of the continental 

 species is most perplexing, and the difficulty of ela.borating 

 species increases as the area of observation is extended and 

 the number of specimens is multiplied. Many so-called 

 species, which have been defined on a few examples taken 

 from local colonies, break down when Ihe work of collecting 

 and comparison has been carried out with due regard to 



