36 -A MONOGRAPH OF 



rounded, not descending ; base convex with radiating striae descending 

 into the deep umbilicus ; interior of the aperture with a little oblong, 

 white, prominent callus tooth nearly at the base ; aperture vertical, 

 semi-lunar ; peristome simple, acute ; margins joined by a thin callus (in 

 some specimens it is very prominent) ; basal margin not reflected. 



Variety a. — Pure white. 



Diameter, greatest 0-13, least 0-11 ; height, 0-11 of an inch. 



Hahitat.—^owoit Wellington, Mount Bischoff, Chudleigh, Gad's 

 Hill, Middlesex Plains. 



I first obtained this remarkable little shell at the Springs, 

 Mount Wellington, and for years afterwards could not find a 

 specimen, although I searched for it repeatedly ; but during an 

 excursion recently I again got it in some numbers in a deep 

 gully about midway between the Huon road, and the Springs. 

 It seems to be very local. The toothed aperture at once isolates 

 it from the rest of our Helices ; it is, in fact, a character not 

 hitherto observed in any of the vast number of described Australian 

 terrestrial shells, or I may say Australasian (perhaps with the exception 

 of ^. hisulcata said to be from this island). This, curious feature of the 

 species is invariably present, but is more prominent in fully mature 

 individuals ; in other respects it presents no great deviation from the 

 usual /aces of our minute Helices, and it is closely allied in form to H. 

 Totella and H. architectonica. 



55. — Helix ( ) rotella — Brazier. 



Pro. Zool. Soc, 1870. 

 Legrand, Col. for Mon,, sp. 51. 



Shell with a small deep umbilicus, orbicularly depressed, rather 

 thin, shining, closely and finely striated, interstices decussated, rusty 

 brown; spire slightly raised; suture deep; whorls 4 J, convex, last 

 rounded, not descending in front, base convex, closely and finely striated, 

 excavated round the umbilicus ; aperture roundly-lunate ; peristome 

 simple, acute ; margins distant, the basal slightly reflexed ; columellar 

 margin not reflected. 



Diameter, greatest 0*19, least 0-15 ; height, O'lO of an inch. 

 Habitat. — Mount Wellington. 



A ^ pretty little species, easily separated. Although somewhat 

 resembling H. dispar, it also approaches H. Legrandi. 



It is rare, only to be got high up the mountain at an elevation of 

 about 3000 feet. I have not found it at any other locality, and it is 

 apparently confined to Mount Wellington, but it is quite possible that 

 it may exist on many of our mountains of a high altitude that have not 

 been examined for land shells. 



