What is the X in X-mas?
Any of various carnivorous or herbivorous mollusks of the class Gastropoda, having a head with eyes and feelers and a muscular foot on the underside of its body with which it moves. Most gastropods are aquatic, but some have adapted to life on land. Gastropods include snails, which have a coiled shell, and slugs, which have a greatly reduced shell or none at all.
Our Living Language : Snails, conchs, whelks, and many other similar animals with shells are all called gastropods by scientists. The word gastropod comes from Greek and means "stomach foot," a name that owes its existence to the unusual anatomy of snails. Snails have a broad flat muscular "foot" used for support and for forward movement. This foot runs along the underside of the animal—essentially along its belly. The Greek elements gastro-, "stomach," and -pod, "foot," are found in many other scientific names, such as gastritis (an inflammation of the stomach) and sauropod ("lizard foot," a type of dinosaur).