402 
THE OCEAN WORLD. 
of Chemnitz, is a great snail, which devours shrubs and trees in wan 11 
countries (Fig. 196). Finally, Vetrinas, the shell of which is very 
small and very thin in some species— so small, indeed, in Vetri n<t 
fasointa (Fig. 197), that the animal cannot re-enter the shell — occtt' 
pies a point of transition between Helix and Limax. 
The Family on Limaceans (Limax) are terrestrial pulmonary 
molluscs, entirely naked, or having only a very small shell. Th e 
Limax varies very considerably in appearance, in consequence of h s 
extreme contractibility. When seen creeping along on the surfed 
of the soil, it has nearly the form of a very elongated ellipse, ‘ at 
one extremity of which is the head; the surface of the body 
contact with the earth is flat, the other convex. Towards th 6 
anterior extremity, and upon the middle of the back, a porfcio® 
of the skin projects as if it were detached from the body, and lS 
ornamented with transverse stripes of various convolutions. Th lS 
part is named the cuirass, or buckler, under which the animal ca® 
hide its head. 
The mouth is a transverse opening in the front of the head ; aboV e 
are two pairs of tentacles, or horns, immensely retractile, cylindrical’ 
and terminating in a small button ; the lower tentacles are the shorter J 
the upper present at their summit a black point, as in Helix, whh’h 
have sometimes been mistaken for the eyes. 
Upon the right side of tho cuirass, and hollowed in the thickn esS 
of its edge, which is large and contractile, whose function it is to gi fe 
access to atmospheric air, it abuts on an internal cavity, also la r » e ’ 
and is intended to promote respiration. The outer skin, or epidermis- 13 
rayed in brownish furrows, its surface covered with a viscous gluti»° llS 
substance, which permits of the animal creeping up the smooth 63 ! 
surfaces, locomotion being produced by the successive contraction aIU 
extension of the muscular fibres of the feet. 
The internal organization of the Limax is analogous to that already 
described in tbe snails. The taste and smell in the Limacea» s 
differ only very slightly from those organs in Helix. They 
like the snails, deaf, and nearly blind. They love fresh aJ ‘ 
humid places; they lodge themselves in the holes of old ^ah 3 ’ 
under stones, or half-decomposed leaves, in the crevices of th 6 
bark of old trees, and even underground, coming forth only 3 
