28 A MONOGRAPH OP 



depressed in front ; spire not raised ; suture large, base rounded ; 

 umbilicus not open ; peristome simple, thin ; aperture ovately lunate ; 

 margins slightly approached ; columellar margin triangularly dilated, 

 concealing the minute umbilicus. 



Variety a. — White. 



Diameter, greatest 0*1 3, least O'll ; height, 0*5 of an inch. 



Habitat. — Piper River ; South Koad, Circular Head ; Blue Tier 

 (Simson), Duck Hiver, Chudleigh, Gad's Hill, and about 

 Launceston. 



Totally dijfferent from any other, and easily recognised by its closed 

 umbilicus and silky appearance. Of rare occurrence in thick, densely 

 timbered places, generally on the ground, but I have met with many 

 specimens deeply buried in decaying trees. Cox remarks concerning it 

 — " This species is closely allied to some of the more finely sculptured 

 and light coloured varieties of S. sericatula (Pfr.) so abundant in New- 

 South Wales." I have a small species from Cape Otway, Victoria (H. 

 Otwayensis, mihi), with much of its general appearance but smaller, paler 

 colour, and difiering in sculpture. It has the general appearance of the 

 last species, but may be at once recognised by glancing at the under 

 surface, when the difference in the umbilicus will be at once seen. 



42. — Helix ( ) Kershawi. N. Sp. 



Shell small, with a deep open umbilicus, depressed, thin, shining, 

 brown ; often marked with dark, nearly black, lines of growth, finely 

 striated throughout with raised riblets the interstices of which are 

 strongly decussated ; spire faintly sunk, or quite flat ; suture much 

 impressed ; whorls 4J, 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. 



Diameter, greatest 3, least 2|^ ; height, 1\ mil. 



Habitat. — Distillery Creek and Cataract, near Launceston ; Corra 

 Linn, River Mersey. 



Variety a. — With black lines of growth. . Habitat. — Cataract, 

 Launceston. 



Variety h. — Spire a trifle elevate, umbilicus not nearly so open. 

 Habitat. — Circular Head, Table Cape, Mount Bischofi". 



I have collected a considerable number of this species on the banks 

 of Distillery Creek, under the herbage that covers the large boulders 

 and rocks. In form and sculpture it is constant, and also in general 



