TASMANIAN LAND SHELLS. 21 



the other hand become perfectly flat with a sharp carination at the 

 periphery ; the prominence of the ribs and their number also vary 

 equally as much as the contour of the shell. I, therefore, think there 

 can be but little doubt but that this species with H. Hobarti belongs to 

 one very variable form. However, as I have not typical specimens 

 from New South Wales, I think it as well to retain the species for 

 further examination. 



29. — Helix ( ) Collisi — Brazier. 



Pro. Royal Soc. Tas., 1876. 



H. minima — Cox. 



Mon., 1868, p. 10, pi. xii., fig. 8. 

 Legrand, Col. for Mon. , species 10. 



Shell broadly umbilicated ; discoid ; shining, yellowish-horny ; 

 very finely striated above, smooth at the base ; whorls 5, regularly 

 increasing, convex, narrow, last whorl a little descending in front ; 

 suture strongly impressed ; spire flat ; excavated round the umbilicus ; 

 mouth lunately-rounded, lip simple, thin ; not reflected at the 

 columellar. 



Diameter, greatest 0*07, least 0'06 ; height P*03 of an inch. 



Habitant. — Mount Wellington. 



I have not seen this species ; it appears to differ from all the other 

 minute forms by the smooth base and finely striated upper surface. 



30. — Helix ( ) Henryana. N. Sp. 



Shell minute, openly, deeply umbilicated, discoidal ; light brown, 

 very highly polished, with very faint traces of lines of growth ; whorls 

 3|^, convex, regularly increasing in size ; suture impressed ; spire 

 slightly elevated ; aperture lunate ; columellar margin not dilated. 



Diameter, greatest 1|^, least 1 j height, f mil. 



Habitat. — Domain, Hobart Town: Clarence Plains (J. A. Petterd). 



Of this minute shell I have only seen four specimens ; they were 

 found by my brother at the localities indicated. Although approaching 

 H. Furneauxensis mihi and R. Halli (Cox), it may be easily known by 

 its depressed form and shining smooth surface. 



31. — Helix ( ) Furneauxensis. N. Sp. 



Shell minute, narrowly umbilicate, conoid ; shinmg, horny, under 

 the lens finely irregularly striated; whorls 4 J, rounded; suture im- 



