2 A MONOGRAPH OF 



Genus— HELIX (LmnceusJ. 



Shell umbilicated, perforated or imperforate, discoidal, globosely- 

 depressed, or conoidal ; aperture transverse, oblique, lunar, or roundish ; 

 margins distinct, remote, or united by callus. 



Animal with a long foot, pointed behind ; lingual teeth usually in. 

 straight rows, edge teeth dentated. 



Distribution. — World-wide : ranging northward as far as the limit 

 of trees, and southward to Tierra del Fuego, but most abundant by far 

 in warm and humid climates — {Woodward). Some thousands of species 

 have been described, and about 270 are recorded from AustraKa. 



1. — Helix ( ) Launcestonensis — Reeve. 



Reeve, Pro. Zool. Soc, 1852, p. 31, pi. xiii., fig. 11. 

 Reeve, Cone. Icon., sp. 968. 

 Cox, Mon., 1868, p. 31, pi. vii., fig. 4, 4a. 

 Legrand, Col. for Mon.. sp. 8. 



Shell umbilicated, conoid, solid, opaque, not shining, finely granu- 

 lated, and closely covered above with wrinkled and granular elevated 

 ridges, spiral lines of various sizes, variegated with yellowish green and 

 black ; spire broadly conical, rather obtuse ; whorls 5, very slightly 

 convex, slowly increasing, last acutely keeled, suddenly descending in 

 front ; base convex, very smooth, shining deep black, with a very nar- 

 row yellow line under the periphery (sometimes wanting), and a broad 

 bright yellow band beneath ; umbilicus rather large, perspective ; aper- 

 ture very oblique. Innately elliptical ; peristome somewhat simple ; mar- 

 gins converging, right slightly curved, then a strong sinuation in front, 

 columellar margin slightly curved, moderately thickened, and slightly 

 reflected. 



Diameter, greatest 1*30, least 1-20 ; height, 0-65 of an inch, 



Habitat. — North-east angle of the island, in the dense brushes on 

 the ground, among decaying vegetable debris, and under 

 logs. 



The largest, most conspicuous, and at the same time most interesting 

 of our Helices, from the fact of there not existing in Australia, or, in 

 short, any part of the world, another species with anything like resem- 

 blance to it. It scarcely ever varies from its normal character. It has 

 not been found in any other portion of the island but that above-men- 

 tioned, although the same circumstances exist favourable to its life. 

 Almost invariably associated with it are Bidimus Dujresni and Helix 

 lampra. I have never collected it in open, dry, forest country, but 

 only in the dense fern-tree and myrtle scrubs. 



The animal is of a rich chocolate broAvn colour. Lingual mem- 

 brane comparatively small, rectangular, 8 mil. long by 2 broad; 170 

 rows of 50-50 teeth, minute, bluntly rounded, slightly diminishing in 

 size towards the margin, arranged in regular straight rows, like tesselated 

 pavement. 



