172 HELICID^. 



upper pair very close together, slightly shagreened, bulbs thick ; 

 lower pair diverging considerably at their base, of a darker 

 colour than the others ; foot greyish-brown, paler towards the 

 margin, ending in a swollen but pointed tail ; lingjial ribbon 

 with 90 rows of 41 teeth = 3690. '' Viviparous " (Rich). 



Shell spindle-shaped, moderately thick and glossy, scarcely 

 semitransparent, chocolate-brown, or horn-colour varying in 

 intensity, marked transversely with irregular streaks of a whitish 

 colour, with numerous close-set, strongish striae in the line 

 of growth, which when viewed through a lens are seen to be 

 intersected in places by faint spiral lines ; periphery angulated ; 

 epider7nis moderately thin ; whorls 10-13, gradually increasing, 

 compressed, body whorl rather narrower than the two above it ; 

 spire tapering, apex obtusely rounded and (as is also the whorl 

 below it) smooth and gloss} ; suture somewhat oblique, moderately 

 well defined, and bordered with a narrow white line ; mouth pear- 

 shaped, considerably contracted above, slightly compressed on 

 the outer side and dilated below, furnished with lamina; or plaits, 

 which are arranged in the following manner : two oblique folds on 

 the base of the penultimate whorl, the upper one prominent, the 

 other less so and situated further within the aperture, sometimes 

 there are from one to three smaller plaits between them ; a 

 semi-lunar fold placed at some distance within the shell upon the 

 pillar, and another slender and indistinct spiral one near to it, 

 but situated further within the aperture ; sometimes there are 

 also one or two denticles inside the outer lip ; outer lip white, 

 thick, detached, and reflected ; basal crest sharp, angular ; um- 

 bilicMS very narrow; clausium "oval-oblong, regularly curved, 

 slightly dilated above," B.C. 



Inhabits all parts of the British Isles commonly, 

 under stones, on walls and rocks, and on the bark of 

 trees. The shell of this species varies considerably 

 in size, colour, and thickness, as well as in the strength 

 of the striation, which in some cases is partially 

 obliterated, owing probably to the manner in which 

 the animal when crawling drags its shell after it. I 

 have noticed that the surface of those shells (of this 



