30 A MONOGRAPH OF 



Diameter, greatest 0'08, least 0*07 ; height, 0*04 of an inch. 



Habitat. — Mount Wellington, Hobart Town waterworks, about 



Launceston, Circular Head, Mersey river ; delights in 



moist situations, among decaying timber and under 

 stones. 



A minute, depressed, finely sculptured form, resembles H. Kershawi 

 and H. Gadensis bub smaller than either, and the sculpture altogether 

 much finer and more compact. If my identification of the shell is cor- 

 rect, the figure in Cox's Monograph is anything but good. 



45. — Helix ( ) Tamarensis. N. Sp. 



Shell widely umbilicated, depressed, rusty-brown, indistinctly rayed 

 with darker shade, dull ; irregularly, somewhat closely striated with 

 rounded and slightly waved striae, interstices with very fine striae ; spire 

 flat ', suture impressed ; whorls 5, convex, last rounded, a little 

 descending, base convex, ornamented with striations the same as upper 

 surface ; umbilicus large and very open, somewhat shallow and flat at 

 the bottom ; aperture ovately-lunate, slightly flattened above ; margins 

 approaching ; peristome simple, acute. 



Diameter, greatest 6, least 5 ; height, 2 mil. 



Habitat. — Rifle butts, near Launceston, in great numbers at the 

 roots of brier bushes (R. M. Johnston). 



Closely allied to H. Legrandi (Cox) and H. Stanleyensis (mihi), but 

 •difiers principally from either in its very open umbilicus and the 

 colouration. It is individually one of the most abundant species I have 

 met with in this island ; it may literally be collected by thousands at 

 the locality given, but, strange to say, I have not met with it elsewhere. 

 It is so different from any described species that I do not think it a local 

 variation. 



I at first named it H, rosacece, but as there is H. rosacea (Miill.) I 

 have altered it to that given above. 



46. — Helix ( ) Officeri — Cox. 



Legrand's Col. for Mon., species 57. 



Shell deeply, openly, but narrowly umbilicated ; depressed, discoid, 

 yellow-brown, very closely and finely striately-ribbed, irregularly and 

 indistinctly rayed with brown ; whorls 5, convex, last not descending in 

 front ; spire almost flat ; suture impressed; base rounded and excavated 



