BY W. F. PETTERD. 41 



The following is a list of tlie Tasmanian species of 

 Ancylus : — 



A. Cumingianus. Bou. 



A. Tasmanicus. Tenison Woods. 



Var. A. B. M. Johnston. 

 A. Woodsi. B. M. Johnston. 



Var. A. do. 



Var. B. do. ' ' ■ 



Var. Y. do. 

 A. Irvince, mihi. 



GUNDLACHIA BEJODOMEI. N. SP. 



Shell small, thin, reddish-brown, diaphanous obliquely 

 conical, concentrically striated with lines of growth ; aper- 

 ture elongately ovate, interior shining, inner aperture serai- 

 circular with a dai'ker margin ; apex, with distinct outline 

 and of a darker shade, obliquely inclined posteriorly and 

 protruding beyond the margin of the outer aperture. 



Length, 4| mill. 



Breadth, 3 „ 



Alt., li „ 



Habitat — Pool off the Brown's River road (Beddome). 



This species differs in shape, colour, and is of a much. 

 larger size than the only other form known here — G. Petterdi, 

 Johnston. (Pro. E.S. 1878) — described from specimens 

 found near Launceston. The genus is a small but very 

 interesting one from the remarkable double-tierred structure. 

 The number of species are very limited — about 7 or 8 — and 

 are, with the exception of the Tasmanian forms, confined to 

 the West Indian Islands and central America. More 

 recently Prof. Tate has discovered G. Betterdi, or a form 

 much like that species, in the vicinity of Adelaide, South 

 Australia. The specie is dedicated to its discoverer, Mr. 0. 

 E. Beddome, the well known conchologist of Hobart. 



