from
The Collaborative International Dictionary of English v.0.48
Gastropoda \Gas*trop"o*da\, n. pl., [NL., fr. Gr. ?, ?, stomach
+ -poda.] (Zool.)
One of the classes of Mollusca, of great extent. It includes
most of the marine spiral shells, and the land and
fresh-water snails. They generally creep by means of a flat,
muscular disk, or foot, on the ventral side of the body. The
head usually bears one or two pairs of tentacles. See
{Mollusca}. [Written also {Gasteropoda}.]
[1913 Webster]
Note: The Gastropoda are divided into three subclasses; viz.:
({a}) The Streptoneura or Dioecia, including the
Pectinibranchiata, Rhipidoglossa, Docoglossa, and
Heteropoda. ({b}) The Euthyneura, including the
Pulmonata and Opisthobranchia. ({c}) The Amphineura,
including the Polyplacophora and Aplacophora.
[1913 Webster]