I40 HELICID^. 



20. H. rupes'tris,* Studer. Pl. VIII. 



Body somewhat oblong, of a dark slaty-grey, or dusky-red 

 colour, with very small, flat tubercles ; upper tentacles dark grey, 

 somewhat diverging, nearly cylindrical, thin ; bulbs large, nearly 

 oval; lower tentacles almost rudimentary, blackish, considerably 

 diverging •,foot broadish, rounded in front, ending in an obtusely 

 pointed tail. 



Shell subconical, somewhat compressed below, rather solid, 

 semitransparent, not very glossy, of a darkish brown colour, with 

 strongish, close-set, curved striae in the line of growth ; periphery 

 rounded in adult, obtusely angulated in immature specimens ; 

 epidermis thinnish ; whorls 5, gradually increasing, their summits 

 slightly depressed ; spire somewhat produced, apex polished ; 

 suture very deep ; vioutJi forming three-fourths of a circle, some- 

 what compressed above ; outer lip thin, scarcely reflected ; 2un- 

 bilicus large and deep. 



Inhabits crevices in rocks and walls, usually in 

 elevated situations, in most parts of Great Britain. It 

 is an inactive and timid creature, but very hardy, and 

 capable of enduring alike the cold of winter and the 

 burning rays of the sun in summer. It is gregarious 

 and ovoviviparous. The shell, owing to its exposure to 

 the sun, as well as to '* wind and weather," is often 

 bleached ; the animal when crawling carries it in an 

 upright position. 



Var. viridescenti-alba. — Shell greenish-white. Clifton near 

 Bristol (Webster), Clevedon, Somersetshire (Norman), B.C. 



21. H. PYGM^'A,t Draparnaud. Pl. VIII. 



Body oblong, rather slender, darkish brown or slaty-grey, 

 with small black specks, tubercles round, flattened; tentacles 

 very slightly diverging, cylindrical, thickish at the base, bulbs 



Living among rocks. f Tiny. 



