HELIX. 219 



dark-grey with black specks ; upper pair rather close together 

 and nearly cylindrical; bulbs short, thick, and subglobular: 

 foot rather narrow, rounded in front, thickened at its sides, and 

 ending in a very slender but blunt tail. 



Shell nearly circular, more compressed below than above, 

 rather thin but nearly opaque, moderately glossy and slightly 

 iridescent, yellowish- brown or horncolour, and marked trans- 

 versely with equidistant reddish-brown streaks or blotches ; 

 sculpture consisting of numerous curved transverse ribs, which 

 are equally strong on both sides and sometimes anastomose, as 

 well as of minute intermediate striae, and of a slight granula- 

 tion on the first whorl, which is destitute of ribs : periphery 

 bluntly keeled : epidermis not very thin : whorls 6-7, subcy- 

 lindrical, convex below, the last occupying about one-third of 

 the shell and the rest gradually diminishing in size : spire 

 slightly raised ; summit glossy and semitransparent : suture 

 very deep : mouth obliquely quadrangular, strengthened in 

 adult specimens by a narrow, but strong, white internal rib : 

 outer lip thickened in the adult, but usually sharp and thin, 

 very slightly reflected, and not much inflected above : umbi- 

 licus extremely large, open, and deep, exposing a considerable 

 part of all the whorls, as well as the whole of the internal 

 spire. L. 0-1. B. 0-275. 



Var. 1. minor. Shell smaller. 



Yar. 2. pyramidal'is. Shell subconical : spire more raised. 



Yar. 3. Turtoni. Shell greatly depressed above and below : 

 5p^Ve nearly flat. H. Turtoni, Fleming, Brit. Anim. p. 269. 



Yar. 4. alha, Moquin-Tandon. Shell pale yellowish-white 

 or with a greenish tinge. 



Habitat : Under stones^ logs of wood_, and bark of 

 old trees, as well as in decayed wood and moss, and 

 among dead leaves, everywhere from the most northern 

 extremity of Great Britain to the Channel Isles. Var. 1 

 appears to be an alpine form. I have found it not only 

 in Zetland, and on the Jura and Swiss Alps, but also in 

 Guernsey. This form occurs also in our upper tertiary 

 beds, probably indicating their northern origin. Var. 2. 

 Swansea and other places (J. G. J.). Var. 3. Dublin 

 (Turton); Bath (Clark); Bristol, and Dunboy in Bantry 



L 2 



