A STROLL BY THE SEA-SIDE. 241 
nothing like an insect whatsoever, but is included in the same 
class of animals with the sea-anemone, from which it does 
not depart in any material point of its structure, except that 
the coral animal deposits lime in its growth, while the sea- 
anemone does not. 
On the moist rocks and wet sea-weed we notice numerous 
little snails, some of them round, about the size of a pea, 
dark brown or dingy yellow in color. Dropping some of 
them into our dish of sea-water, we observe their movements 
plainly. A little soft-bodied animal, slug-like, with two 
feelers or tentacles thrust out ahead, having at their base a 
pair of little black eyes, and between the feelers a roundish 
trunk like an elephant’s proboscis, only very short. This 
they apply closely to the surface upon which they rest. The 
mouth opens at the end of this snout. A little tongue within 
the mouth, furnished with numerous minute hooks, keeps up 
a continual lapping movement, rasping off the minute vegeta- 
tion upon which they feed. Looking through the glass jar 
in which they may be kept, we not only notice the motions 
of the tengue, but the manner in which they crawl, moving 
first one side and then the other of the disk-like foot, which 
seems to be divided by a longitudinal furrow. Notice how 
gracefully they twirl the shell in their movements. Taking 
4 few in our hand, they quickly withdraw within their shells, 
and, as they disappear, a lid, called the operculum, which is 
attached to the tail, closes the aperture effectually. Nearly 
all of the marine snails, and many of the land and fresh- 
Water snails likewise, are furnished with this operculum. 
The eye-stone, so-called, is nothing more than the oper- 
culum of some tropical snail; for the opercula of our northern 
snails are mostly of a horny nature, very few species having 
“dreous opercula. 
The Species we have just described is called Littorina pal- 
Their habits are such that they require a submer- 
Sence in the sea-water of only a few hours each day. For 
AMER. NATURALIST, VOL. II. 31 n 

