18 AUSTRALIAN LAND SHELLS. 



43. Helix vinitincta. Cox. Plate I. Fig. 6, 6 a. natural size 

 and magnified. M.C. 



Shell umbilicated, on both sides depressed, involute, thin, horny, 

 closely covered with plait-like riblets, not shining, covered with a 

 deep reddish-chestnut epidermis ; spire concave, the whorls forming 

 an upper, wide, spiral umbilicus, penetrating of the thick- 

 ness of the shell ; whorls 4, quickly increasing, last narrower than 

 high, convex along the periphery, witli an obsolete ridge above com- 

 pressed from behind ; base flatly rounded, almost ribbed as above ; 

 umbilicus very open, exposing the whorls, shallow ; aperture oval, 

 twice the length from above downwards as from before backwards, 

 almost vertical ; peristome simple, very slightly thickened and 

 everted, margins separated by the last wliorl which bulges into the 

 centre of the oval aperture. 



Diameter, greatest 027 ; least 0*23; height 0-10 of an inch. 



Habitat. Upper Richmond River, under logs in the brushes."- 

 MacGillkray. 



Closely allied in form to those specimens of H. micron, which have 

 the spire submersed, but wanting the red markings, attaining a 

 much larger size, and being of a deep vinous hue all over. 



44. Helix Omicron. Pfr. Plate X. Fig. 1, natural size and 

 magnified. M.C. 

 Pfr.,' Zeit-schrift fur 3/alac, 1851, p. 128. 



H. Ammonitoides. Reeve, Conch. Icon. sp. 1246. 



Shell umbilicated, depressed, concave on both sides, thin, very closely 

 covered with thread-like ribs or folds, not shining, horny, with 

 numerous streaks and zigzag markings, straight, curved, and 

 oblicpie ; spire either deeply concave or level with the surface ; 

 whorls 4, very rapidly increasing, convex, last large, rounded, higher 

 than broad, not descending in front ; below plicately ribbed as 

 above ; umbilicus with steep margin, conical, about 3 of the diameter ; 

 aperture almost vertical, broadly-lunar ; peristome simple, thin, 

 ] uargins remote, yet tending to converge, outer regularly curved, 

 columellar margin slightly sinuated below and then slanting upwards. 



Diameter, greatest 0-22 ; least - l8 ; height - 08 of an inch. 



Habitat. Richmond River. MacQillivray. Brisbane. Masters. Port 

 Curtis. Blaekman. Var. from Clarence River. 



Although a variable species, it yet may be generally recognised at 

 once by the red markings, which, however, vary in intensity, and 

 are wanting in some small pale specimens. 



45. Helix ziczac, Gould. 



Gould, Pro. Bod. Soc, 1846, p. 166. 



Gould, Expedition Shells, 1851, p. 41. Fig. 44. 



Shell small, rounded, depressed, whitish-straw-coloured, painted with 

 small, oblique, lightning-like, brown Hues, and furrowed with acute, 

 closely-set, reflected, hairy plates; beneath convex, perforated with a 



