88 LAND AND FRESH-WATER MOLLUSKS. 
the right side behind and near the upper ten- 
tacle. The eggs are oval, inflated at the middle, 
hard, and opaque, with a calcareous shell, and 
resemble the eggs of some reptiles ; when placed 
before a fire, or even exposed in a dry atmo- 
sphere, they in a few minutes explode with a 
loud crack. The mollusk lays its eggs, ten to 
fifteen in number, in a subterranean gallery 
during the months of May, June, and July; the 
egos are isolated tone from the other, and are 
not united in a mass, as in the true slugs; the 
young Testucelles are excluded in from twenty- 
five to thirty days. The food of the young slugs 
consists of small worms, and the white, slender, 
vermiform animals which live upon putrefying 
vegetables. They do not grow so rapidly as the 
Tnmaces. | 
The Testacelle, though subterranean in 
their habits, may be met with at the surface 
during the autumnal months, and before day- 
break in April; in winter, they bury from one 
to two feet deep in the soil, and “ form a kind 
of cocoon in the ground by the exudation of 
= mucus. If, this celia 
broken, the animal may be 
seen completely shrouded in 
its thin, opaque, white mantle 
bine let (fig. 16, m), which rapidly 
disturbed from its sleep. contracts until it extends but 
