166 HELICID^E. 



5. Z. RADIA'TULTJS*, Alder. 



Helix radiatula, Aid. Cat. Northumb. Moll. p. 13. Z. radiatulus, 

 F. & H. iv. p. 38, pi. cxxi. f. 1. 



BODY dark horncolour : tentacles nearly black, the upper 

 ones very slender and the lower pair short : foot exceedingly 

 narrow, pointed behind, its sides marked with minute black 

 specks. 



SHELL compressed, equally convex on both sides, very thin, 

 remarkably glossy, semitransparent, dark horncolour, dis- 

 tinctly and beautifully marked across the whorls on the 

 upper side by strong curved and close-set striae which reach 

 the suture, the under side being also marked, but less dis- 

 tinctly, by similar striae : epidermis thin : whorls 4 J, convex, 

 and very little dilated laterally, the last occupying rather 

 less than one half of the shell : spire slightly raised : suture 

 moderately deep : mouth nearly round, sometimes thickened 

 inside by a broad but slight white rib : outer lip scarcely 

 oblique : umbilicus narrow, but rather deep, disclosing all 

 the internal spire. L. OO75. B. O15. 



Var. viridescenti-alba. Shell greenish-white. 



HABITAT : Under stones, logs of wood, dead leaves, 

 and moss in woods, from the Moray Firth district to 

 Dorset. The variety is from Shropshire, Co. Cork, and 

 Co. Tyrone (J. G. J.) ; Belfast (Thompson). This species 

 is one of our upper tertiary fossils. Malm has recorded 

 it as a Swedish shell, Scholtz as Silesian, Moquin-Tan- 

 don and others from different parts of France, Stabile 

 from Lugano, and myself from the Lower Harz and 

 Switzerland. 



This little mollusk is less shy and inactive than Z. 

 puruSj and usually frequents moister places. It re- 

 sembles that species in the size and form of the shell ; 

 but the peculiar sculpture, more glossy appearance, and 

 narrower umbilicus of the present species will easily 

 serve to distinguish it from Z. punts. 



* Slightly rayed. 



