52 PULMONATA. 



*** Shell exposed, more or less covered by the thickened o: 

 reflexed processes of the edge of the mantle. 



8. ViTRiNKLLA. Shell imperforate, very thin ; spire conic. 



Mantle lobe covering the greater part of the shell. 



9. Helicarion. Shell imperforate, very thin, depressed ; spire 



short, last whorl very large. Mouth very large, lunate or 

 rounded. Mantle lobes small. 



10. Nanina. Shell perforated, depressed, smooth below. 

 Mouth lunate. Peristome straight, simple. 



11. Stenopus. Shell perforated, conical or depressed, thin, 



diaphanous, last whorl broadest. Mouth roundish lunate. 

 Peristome acute. 



**** Shell exposed. Edge of mantle not reflexed. 



12. Ariophanta. Shell sinistral, umbilicated, thin, diaphanous. 



Mouth oblique. 



13. ZoNiTES. Shell dextral, umbilicated, thin, horn-coloured. 

 Mouth lunate ; lip rather thickened within. 



A. Body elongate, attached its whole length to the upper surface 

 of the foot. Mantle shield-like, simple, entirely enclosing a 

 flat, oblong, not spiral, shell, or only some calcareous gra- 

 nules. Subcaudal gland lunate, horizontal, transverse. 

 Arionina. 



1. ARION. 



Elongate, subcylindrical. Tail tapering, with a large mucous 

 pore over the tip. Shield anterior, shagreened. Pulmonary 

 cavity anterior, under the shield ; aperture anterior. Orifice of 

 vent quite contiguous, inferior. Shell ovate, or only some cal- 

 careous granules in the cavity of the shield. 

 Arion, Ferussac, Tab. Syst. 10. 16. 96 ». 96 ''. 1817, 1821 j HJ«f., 

 Moll. ii. 53. 



Gray, Tiirton's Manual, 104; P. Z. Soc. 184/, 169. n. 429. 

 Fleming, B. A. 256, 1828. 

 Leach, Brit. Moll. 45. 

 Limacia, Hartmann, NeueAlpiner, 208, 1821. 



S^e//.— Limacella, Brard, not Blainville. 

 Limacellus, Turton. 



