242 COOKE : ON AUSTRALIAN LIMNjE^. 



Locality: Australia (W. Newcomb, M.D.), India? (W. A. 

 Haines), Victoria R. and Depuch I., N. Australia (Smith). 



Described by Tryon as an Isidora, which subgenus, how- 

 ever, seems peculiar to Africa (see the monograph in Klister). 

 2. Physa Newcombi Ad. and Ang. P.Z.S., 1863, p. 416. 

 ,, „ Smith, Journ. Linn. Soc. Zoo!., vol. 



xvL, On the Freshwater Shells of 

 Australia, p. 280. 

 „ „ Sowb., Conch. Icon., vol. xix.j/yzj'j-*?, 



fig. 21. 

 „ „ Klister, Mart, and Chem. Conch. 



Cab., Physa, nr. 131, p. 299, taf. 43, 

 fig. 6. 

 Locality : Ponds near Mount Margaret, Stuart's Exped- 

 ition (Angas). 



Type in Mus. Brit. 



There is no evidence, in the descriptions of these two 

 shells, that their authors examined the animal. The shells 

 being sinistral, and rather large and ventricose, it probably did 

 not occur to them that they were anything else but Physa, or 

 that it were possible, perhaps, for a species of Limncea to be 

 permanently reversed. Mr. Gwatkin's examination of the 

 animal of our shells was confined to the dentition, but was 

 sufficient to establish beyond the possibility of a doubt that 

 they were Limnaa and not Physa. If, therefore, we find that 

 on conchological grounds these two other species from the 

 same part of Australia, hitherto described as Physa, approach 

 very closely to ours, there are strong grounds for believing — in 

 the absence of the certainty which an examination of the radula 

 would afford — that they also are Limncea. 



In a question like this, an examination of the type speci- 

 mens is the most convincing test that can be applied.* The 

 outer surface of the shell, in all these three species, is that of a 



* I will place the type specimen of the new species in the Mus. Brit. 



J.C, v., Oct., 1887. 



