ZONITES. 37 



Diameter about three-eighths of an inch. 



The animal is, according to Mr. Alder, of a dark lead- 

 colour, darker than cellarius. It is not so common, but 

 is probably much more widely distributed than usually 

 supposed. It inhabits shady places, under stones. 



Z. purus, Alder. 



Small, depressed, smooth, whitish and transparent both above 

 and below ; body whorl decidedly broader than the preceding 

 turn ; outer lip acute ; umbilicus rather large. 



Plate CXXI. fig. 5, 6. 



Helix nitidula, var. Drafar. Moll. Terr, et Fluv. France, p. 117, pi. 8, f. 21, 

 22. — Jeffreys, Trans. Linn. Soc. vol. xvi. p. 340, 511. 

 — C. Pfeif. Deutsch. Land und Siissw. Moll. pt. 1, p. 45, 

 pi. 2, f. 35. 

 „ nilidosa, Ferus. Prodrom. Moll. No. 214 (no descr. ) — RossmAssl. 

 Iconog. Land und Siissw. Moll. pt. 1, p. 71, pi. 1, f. 23. — 

 Krynicki, Bull. Soc. Nat. Moscou, vol. ix. p. 205. 

 „ crystallina, Fleming, Brit. Anirn. p. 262 ? 



„ pura, Alder, Trans. Nat. Hist. Soc. Northurnb. vol. i. p. 37 ; Mag. Zool. 

 and Bot. vol. ii. p. 108. — Turton, Manual L. and F. W. Shells, 

 p. 59, f. 43 (badly magnified). — Thompson, Ann. Nat. Hist, 

 vol. vi. p. 32. — Brown, Illust. Conch. G. B. p. 53. — Chemn. 

 (ed. Kiist.) Conch. Cab. Helix, No. 511, pi. 83, f. 17 to 19.— 

 L. Pfeif. Monog. Helic. vol.i. p. 96 (not var. /3). 

 „ viridula, Menke, Synops. Moll. ed. 2, p. 127. 

 „ lenticula, Held, Isis, 1837, p. 304. 

 Polita nitidosa, Held, Isis, 1837, p. 916. 

 Helicella „ Beck, Index Moll. Mus. Christ. Frid. p. 6. 

 Helix electrina, Gould, Bost. Journ. of Nat. Hist. vol. iii. p. 423, pi. 22, f. 2. — 



Invert. Massach. p. 183, f. 111. 

 Zonites purus, Gray, Manual L. and F. W. Shells, p. 171, pi. 4, f. 43. — Macgil. 

 Moll. Aberd. p. 92 (probably). 



Shell small, depressed, transparent, moderately shining, 

 thin, white or occasionally very pale horn coloured, of 

 an uniform tint, not becoming opaque underneath, almost 

 smooth, or at most obscurely wrinkled by the lines of 



