JOURNAL OF CONCHOLOGY. 159 



NEW SPECIES OF FRESH-WATER SHELLS FROM 



AUSTRALIA. 



By W. F. PETTERD. 



[Read before the Conchological Society] 



I. Bithynia Richmondiana n. sp. Shell cylindrically 

 elliptical, sub-umbilicate, pale greenish, horny, thin, 

 shining ; spire roundly obtuse ; whorls 4J, very con- 

 vex, suture much impressed ; aperture ovate, distinct 

 from whorl, entire; operculum yellowish, horny. 

 Length 3 mill,, breadth i^^ mill. 



Habitat, creeks running into the Richmond river, 

 New South Wales. 



Occurs in some abundance on stones and plants 

 in somewhat swift running streams. Its form and 

 colour distinguish it from any other described Austra- 

 lian species known to me. 



Amnicola positura n, sp. Shell globosely conical, 

 sub-umbilicate, sharply carinate, above conically acute, 

 lower surface convex; colour almost black, often 

 coated with Diatomacce ; whorls 5^, suture marginate 

 and impressed ; aperture pyriform, almost entire, 

 outer lip expanded. Length 3 mill., breadth i^ mill. 



Habitat, Richmond River, New South Wales. 



I collected a considerable number near Lismore, 

 on the above river. It is very plentiful, but seems to 

 be a local species. It may be known by the acute 

 carination, robust form, and dark coloration. 



Aynclus assimilis n. sp. Shell small, broadly ovate, 

 dark horny brown, dull, striate ; apex twisted ; aper- 

 ture dark brown within. Length 3 mill, breadth, 2 

 mill., height i| mill. 



