PETTERD : ON SOME NEW TASMANIAN HELICES. 211 



suture deeply excavate; aperture roundly lunate, not descend- 

 ing, margins distant, joined by an extremely thin deposit of 

 callus ; columella not dilated. 



Diam., greatest 2^, least 2; height i mil. 

 Habitat — Distillery Creek, near Launceston. 



Of rare occurrence, attached to the under surface of 

 large boulders in moist places. Easily recognised by the 

 sudden termination of the striae on the apical whorls and the 

 pure white color. 



H, Kershawi, n. sp. 



Shell small, with a deep open umbilicus, depressed, 

 thin, shining-brown, marked with black lines of growth, finely 

 striated throughout with raised riblets, the interstices of which 

 are strongly decussated; spire faintly sunk, often flat; suture 

 much impressed; whorls 4^, rather convex, last rounded, 

 descending slightly in front and flattened above; aperture 

 triangularly-ovate; margins distant, basal a little everted, 

 joined by a very thin polished callus. 



Diam., greatest 3, least 2^; height i^ mil. 



Habitat — Distillery Creek, near Launceston. 



I have collected a considerable number of this species 

 on the banks of the creek under the vegetation that covers 

 the large boulders and rocks. Found in company with 

 H. neglecta Brazier and H. Halli Cox. 



H. mimosa, n. sp. 



Shell small, openly umbilicated, reddish-brown, irregu- 

 larly rayed and blotched with pure white, which markings 

 are more conspicuous above than below; regularly closely 

 striated throughoutwith slightly waved, thread-like strise; spire 

 flat; suture impressed; whorls 4)^, convex, apical, smooth, 

 the last narrow, rounded, not descending, below striated as 



