LIMAX. 
75 
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 
length of the foot. 
1. Limax Fh, (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 Avion ; 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.). 
