MOLLUSCA
Mollusca, phylum Mollusca
(noun) gastropods; bivalves; cephalopods; chitons
Source: WordNet® 3.1
Mol*lus"ca, n. pl. Etym: [NL. See Mollusk.] (Zoöl.)
Definition: One of the grand divisions of the animal kingdom, including the
classes Cephalopoda, Gastropoda, PteropodaScaphopoda, and
Lamellibranchiata, or Conchifera. These animals have an unsegmented
bilateral body, with most of the organs and parts paired, but not
repeated longitudinally. Most of them develop a mantle, which
incloses either a branchial or a pulmonary cavity. They are generally
more or less covered and protected by a calcareous shell, which may
be univalve, bivalve, or multivalve.
Note: Formerly the Brachiopoda, Bryzoa, and Tunicata were united with
the Lamellibranchiata in an artificial group called Acephala, which
was also included under Mollusca. See Molluscoudea.
MOLLUSCUM
Mol*lus"cum, n. Etym: [NL. See Mollusk.] (Med.)
Definition: A cutaneous disease characterized by numerous tumors, of
various forms, filled with a thick matter; -- so called from the
resemblance of the tumors to some molluscous animals. Dunglison.
Source: Webster’s Unabridged Dictionary 1913 Edition