LIMAX. tS 



9. Achatina. Shell turreted, elongate ; mouth 

 ovate ; inner lip truncated in front ; peristome 

 thin. 



10. Pupa. Shell cylindrical, blunt ; mouth sinu- 



ous ; peristome reflected. 



11. Vertigo. Shell cylindrical, blunt ; mouth 



toothed ; peristome thickened behind. 



12. Balea. Shell fusiform, elongate : mouth ovate, 



clausium none. 



13. Clausilia. Shell fusiform, elongate; mouth 



toothed, with an elastic clausium. 



§ 1. Scutifera. — Body elongate, attached the whole 

 leniTth of the foot. 



1. LiMAX Per. (Slug.) 



Body elongate, lanceolate, granular, keeled behind ; 

 mantle shield-like, ovate, concentrically lined ; 

 shell internal, sub-quadrate, flat, nail-like 

 (fig. 29.). 



These animals have very much the external ap- 

 pearance of Arion ; but they are destitute of the 

 gland on the end of the tail, their mantle is marked 

 with circular striae instead of being granulated, and 

 they have a different nervous system, for, according 

 to Mr. Nunneley, the infra-oesophageal ganglion is 

 like that of Arion, but the under side, instead " of 

 having one transverse fissure, has two, so that it 

 presents, on each side of the medial line, three gan- 

 gliform eminences instead of two only." Jaw 

 strong, smooth, with a strong central projection 

 (fig. 27.). 



