[AS.] A soft slimy land mollusc, usually protected by a spiral shell. Besides long tentacles tipped with black eye-specks, snails have a shorter pair, which are organs of smell. There are over 2,000 species of snails, and they are found in all parts of the world except the Arctic regions. Some are even smaller than a pin-head; while others, in France and Italy, cultivated for food, are fairly large. The Great Vine Snail was considered a table luxury by the ancient Romans. Snails are vegetarians, and have jaws and tongues of saw-like edge, with thousands of rasping points on each. On the approach of cold weather the snail throws a film over the mouth of its shell, which tightens like a drum-head. Snails have astonishing vitality. They regain activity after having been frozen in solid blocks of ice, and endure a degree of heat for weeks which daily crisps vegetation. In very dry weather they close up the shell as in cold weather, to retain the bodily moisture.