BY \V. L. MAY. 67 



enough remained to enable a satisfactory identification 

 and figure to be made. Two Pisidium and one Cvcjas 



also described, and Valvata tasmanica, now placed in 

 Petl rdiana. A very unsatisfactory feature of this de- 

 scription is that it is printed on a -'ip attached to page 

 82, P. and I\ Royal Society, Tas., for 1875. immediately 

 below Cyclas tasmanica; this is missing from the copy 

 in the Royal Society Library, and may be from others. 

 It may therefon be well to reprint the English portion 

 of the original description, which is as follows: — 



"Sht It minute, globosely turbinate, deeply and widely 

 umbilicate, pale ho with a blackish epidermis, 



rather -lid, semi-p [lucid; whorls 4, rounded, faintly 

 undulately atrial . subcanaliculate at the sutur s; aper- 

 ture semi-lunate, sub-reflexed, posteriorly angulate; in- 

 ner lip straight and thin; umbilicus margined. Opercu- 

 lum horny, ova] and subepiral, Long. !. Lat. 1. milli- 

 meters." 



\V. F. Petterd, who i- so well and favourably known 

 for his work on th oian land -loll., also gave con- 



siderable at! ntion to the freshwater forms. He gives 

 a. very useful list of tin species a- then known in the 

 Journ. Conch, ii.. L879, p 80, with comments and some 

 correction-. In his Contributions i'<>r a systematic cata- 

 '>t' Aquatic shells in P. and P. Roy. Soc. Tas. for 

 . he d ah more thoroughly and completely • with this 

 group than any other worker; and at the same time 

 ten new ral varieties, and pub- 



lished with the oaper a large number of figures; many 

 of th vit, especially of the smaller specii 



roughly executed, and are of little value for identi- 

 fication. Most of his re now in the Launo 



am, and I had an opportunity before they were 

 of examining them carefully, and figuring 

 most. Of his two species of Lyninaa. L. lutosa is in my 

 opinion only one of the common forms of L. peregra in- 

 troduced from Europe. Ili> Potamopyrgus wood si equals 

 ]'. tasmanica von Martens; his Assiminia Ucincta is con 

 specific with A. tasmanica, Tenison-Woods, and his two 

 mini -, P. smithii, and P. dyeriana, arc some- 



what doubtfully distinct from /'. gunnii, of which they 

 may he micromorphs. 



.Finally, R. M. Johnston, P. and P. Roy. Soc. Tas. for 

 1879, describ d Gundlachia petterdi, and Ancylus woodsi, 

 the latter being the undeveloped form of the former, also 

 an Amnicola and two Planorbis. Op. cit. for 1SS8, p. 

 ir critical tions <>n recent contributions to 



"in- knowledge of the Freshwater -hells of Tasmania, 



