8O LAND AND FRESH-WATER SHELLS. 



to Jth inch ; umbilicus moderately deep. Among moss and 

 wet grass. Generally distributed, but not common. 



H. radiatula^ 



(//) Shell subglobular, chocolate-brown, no white on under side, 

 solid, glossy, semi-transparent ; whorls five, body-whorl occupying 

 one-half of the shell ; spire produced, with the apex blunt ; mouth 

 roundish, forming three-fourths of a circle ; umbilicus narrow, 

 deep. Diameter | inch. Marshes and banks of ditches. 



H. nitida. bl 



(i) Shell suborbicular, not very glossy, darkish horn-coloured, 

 coarsely striated ; whorls five and a-half ; spire slightly produced ; 

 mouth nearly circular ; umbilicus large, disclosing all the internal 

 spire. Among moss and dead leaves in woods. Local. 



H. excavata. 



(/') Shell flat above, convex below, vitreous, smooth, glossy, 

 transparent ; whorls four and a-half to five, the body-whorl being 

 scarcely smaller than the preceding whorl ; mouth lunate ; 

 umbilicus very small. Diameter -^-ths inch. Among moss and 

 decaying leaves in woods and hedgerows. Common. 



H. crystallina.^ 



(k) Shell conical, dark horn-coloured, smooth, glossy, semi- 

 transparent ; whorls five and a-half to six ; periphery bluntly 

 keeled ; spire produced ; mouth semilunar, narrow ; umbilicus 

 shallow, indistinct. Diameter -j^th inch. Under stones and 

 among decaying leaves in woods and hedgerows. Moderately 

 common. H. fulva.^ 



18. Helix. Shell globular, turreted, convex or flattened ; 

 mouth more or less circular or oval ; outer lip generally thick and 

 possessing an internal rib, sometimes reflected and provided with 

 tubercles or teeth ; umbilicus sometimes absent but usually distinct. 



(a) Shell conoid, globose, thin, horn-colour ; epidermis raised 

 into numerous close-set plaits in line of growth ; whorls six, 

 convex ; spire blunt, slightly depressed ; mouth crescent-shaped ; 



56 v. viridesctnti-albci) greenish-white. 



57 v. albinos, whitish. 



58 v. complanata, flatter on both sides, last whorl proportionally larger. 



59 v. Alderi, smaller, darker brown ; v. Mortoni, depressed above, less 

 flattened below, peripheral keel sharper. 



