230 HELICID.E. 



parts ; tubercles oblong and arranged in close lines, smaller in 

 front : mantle tumid, forming a narrow collar and leaving a 

 slight space empty round the neck: tentacles very long and 

 slender, dark-brown, shagreened; bulbs very globular: foot 

 deUcately edged with milk-white, ending in a long, narrow, tri- 

 angular and keeled tail. 



Shell nearly circular, shaped somewhat like one of the men 

 in a backgammon board, except that this is spiral, flat above, 

 with a slight depression in the middle, and compressed below, 

 rather solid, opaque and of a lurid aspect, reddish-brown, finely 

 and closely striate in the line of growth : periphery rounded, but 

 compressed : ejjidermis very thick, closely covered with stiff 

 reddish-brown hairs : ivhorls 6^, cylindrical, but compressed at 

 the sides, gradually increasing in size, the first (being the 

 nucleus of the shell) nearly smooth and polished, and the last 

 slightly dilated towards the mouth : spire sunk below the level 

 of the last whorl : suture rather deep : mouth obUquely tri- 

 angular, in consequence of a tooth-like protuberance at the 

 peripheral edge : outer Up reddish-white, very thick and re- 

 flected, its upper margin abruptly and considerably inflected : 

 umbilicus rather large, exposing part of the whorls (especially 

 the last but one) and all the internal spire. L. 0-2. B. 0*5. 



Habitat : On stumps and at the roots of trees in woods 

 at Ditcham and Stoner Hill near Buriton^ in Hampshire, 

 where it is rather common. It is a native of France, 

 Germany, Switzerland, and Lombardy ; but it does not 

 seem to inhabit the extreme North or South of Europe. 



This curiously-shaped snail is rather active, and 

 secretes a good deal of clear slime. Its epiphragm is 

 chalky-white and remarkably thick. 



Considerable doubt has been raised by many British 

 conchologists (myself included) as to H. obvoluta being 

 really indigenous to this country. It was first noticed 

 by Dr. Lindsay (in 1831) as occurring in Ditcham 

 Wood. He found with it Zonites cellarius and Helix 

 rufescens. Mr. Hawker says, in the ' Zoologist ' for 1853 

 (p. 3764), "The two ridges (Stoner Hill and Ditcham 

 Wood) are quite distinct, and the intervening country 



