68 MOLLUSCA. 
VALUE.—Cultivated for food—an important industry in France, 
NoTEe.—Most of the snails hibernate in the cold seasons, and wil} 
live for years without food. The largest are the agate shells of 
Africa, eight inches across; the eggs an inch in length, with a 
hard covering. The Helicarion gutta of the Philippine Islands, ac- 
cording to Semper, when caught by the tail, throws it off and sc 
escapes, the tail in time growing again. This is also the case with 
a West Indian snail (Stenopus). Helix hortensis, common in New 
England, was introduced years ago from England. Helix fidelis is 
an albino, found in Washington Territory. 
Fic. 71.—Bulimus rosaceus, 
Land-Slugs (Limcidz).—These slugs (Fig. 70, C), of 
which 116 different species are known, are common in every 
garden, and their bright- 
yellow eggs found under 
old boards oy buried in the 
ground. They have, asarule, 
arudimentary scale-like shell 
(Fig. 70, S), long tentacles, 
and are carnivorous, eating 
worms and other animals. 
They have a curious secre- 
tion by which they lower 
themselves from twigs and 
leaves. It is also a defense, 
and when applied to many 
animals, as moles, is often 
fatal. Lemax noctiluca, from 
Fic. 72.—Onchidtum tonganum, a 
g . mollusk with dorsal eyes; natural 
Teneriffe, has a luminous size. 
