FAMILY C0L1MACEA. 79 



17. Helix fusca. Fuscous Helix. 



Shell ; scarcely umbilicated, depressed, very thin, membranaceous, 

 glossy fuscous-olive, spire convex, sutures rather 

 impressed, whorls five, arcuatelyplicately wrinkled, 

 minutely hairy, slopingly convex, last whorl obso- 

 letely angled at the periphery ; aperture lunar, lip 

 simple, basal margin shortly dilated round the um- 

 bilicus. 



Helix fusca, Montagu (1803), Test. .BnY.p.424. pi. xiii. f. 1. 



Helix ( Zenobia) corrugata, Gray (1820), Lond. Med. Repos. 

 vol. xt. p. 239. 



Helix subrufescens, Miller (1829), Ann. Phil. New Series, 

 vol. iii. p. 379. 



Zonites fuscus, Macgillivray (1843), Moll. Aberd. p. 93. 



Vitrina membranacea and margaritacea, Brown (1845), Illus. Condi. Brit. 

 pi. xl. f. 3 to 5 and 54 to 56. 



Helix (Zenobia) fusca, Moquin-Tandon (1855), Hist. Moll. vol. ii. p. 212, 

 pi. 15. f. 33 to 36. 



Hab. Throughout Britain. Western maritime parts of France. (In woods 

 and bushy places, under leaves or upon brambles.) 



The shell of H. fusca is larger and more depressed than that of 

 H. revelata, but of the same membranaceous substance, wanting 

 the greenish cast of colour. The umbilicus is even smaller, often 

 scarcely distinguishable, and the hair is so fine and deciduous that 

 the surface is frequently supposed to be without hair. M. Moquin- 

 Tandon describes the animal as being irritable, especially in front, 

 keeping the upper tentacles always in motion, and crawling with 

 some rapidity. " Individuals of this species," he adds, " love to 

 congregate, and reciprocally polish each others' shell with the foot." 



A peculiar interest attaches to this species. It is found in all 

 parts of Britain south of Aberdeen, and has been known from the 

 commencement of the present century. But H. fusca was not ob- 

 served on the Continent until 1838, and then only in the part nearest 

 to Britain. The first record of its appearance out of Britain is by 

 M. Bouchard-Chantereaux, who, under the name of II. revelata, for 

 which species he mistook it, describes it as being common in the 

 neighbourhood of Boulogne. The Abbe Dupuy gives also Mont- 

 de-Marsan as a habitat ; and M. Grateloup has collected it at Dax, 

 between Bordeaux and the Pyrenees. Is it then an instance of an 

 originally British type, spreading in a direction contrary to that 



