48 AUSTRALIAN LAND SHELLS. 



ture lunately-oval ; peristome white, thin, expanded, reflected, mar- 

 gins approximating, columella! - partially concealing the umbilicus. 



Diameter, greatest 000 ; least - 50 ; height 0\30 of an inch. 



Habitat. Widely distributed, from South Australia and Victoria, 

 through New South Wales and Queensland to Cape York ; and the 

 Islands in Torres Strait. 



From so extensive a geographical range this species might be expected to 

 vary much. Those described are of the largest size, from the Clarence 

 .River. But the shell is usually smaller, very thin, shewing under 

 the lens little of any wrinkling of the surface, and having the spire 

 either flat or even submersed. A pretty smooth variety from Cape 

 York has the spire as acute as in those described. In large speci- 

 mens the pili almost entirely disappear. Those I have from Vic- 

 toria are unusually dark in colour. 



123. Helix Porteri. Cox. Plate III. Fig. 6 a., 6 b. M.C 

 Cox, Pro. Zool. Soc, 1866, p. 373. 



Shell umbilicatecl, depressly-circular, rather swollen, under the lens 

 obsoietely plicately striated, minutely granulated, and thickly studded 

 with veiw short hairs, reddish-chestnut ; spire small, obtuse ; whorls 

 4^-, convex, last swollen, suddenly deflected in front, constricted 

 behind the mouth ; aperture roundly-lunate ; peristome rather thin, 

 expanded, white, margins approximating, lower border rather 

 straight, columellar margin dilated above and reflected, partially 

 concealing the umbilicus. 



Diameter, greatest 0"7o ; least 0*63; height 0'50 of an inch. 



Habitat. Upper Clarence River, at Guy Faux. Porter. Upper 

 Richmond River, at Cowlong, in Cedar brushes under logs. Mac- 

 Gillkray. 



This shell bears much general resemblance to specimens of H. mansueta, 

 from the Pine Mountain, Lis more, which are darker than Queens- 

 land specimens ; but the presence of pili, the white lip, the 

 narrower and more covered umbilicus, are very distinctive characters 

 in H. Porteri, which is besides closely allied to the more diminutive 

 H. brevipila, and occupies a place between it and H. mansueta. 



124. Helix Hystrix. Cox. Plate XVII. Fig. o, natural size, 

 5 a. and 5 b. magnified. Australian Museum. 



Shell openly umbilicated, discoid, flattened on the top, yellowish-brown, 

 covered with coarse long bristles in regular rows ; whorls 5, gradu- 

 ally increasing, rounded, last descending in front, suture deep and 

 narrow ; aperture diagonal, rounded ; peristome simple, lip everted, 

 columellar margin not dilated. 



Diameter, greatest O'oo ; least 0-44 ; height 0'23 of an inch. 



Habitat. Port Curtis. Cox. 



Unlike any other Australian species, and at once recognised by its 

 discoid form and bristled surface. 



