| 释义 |
mol·lus·ca
\məˈləskə\ noun plural
Usage: capitalized
Etymology: New Latin, from Latin, neuter plural of molluscus soft, from mollis — more at melt
: a large phylum of invertebrate animals that include the chitons, tooth shells, snails, mussels and other bivalves, octopuses, and related forms and that have a soft unsegmented body lacking segmented appendages and commonly protected by a calcareous shell secreted by a mantle which extends from the body wall usually as an enveloping fold; a muscular foot which is formed from part of the ventral surface of the body and is variously modified for creeping, digging, or swimming; a well-developed heart and vascular system and usually one or more pairs of gills; a complex nervous system with several pairs of ganglia and longitudinal and transverse commissures; and frequently more or less complex eyes and otocysts — compare amphineura, cephalopoda, gastropoda, lamellibranchia, scaphopoda |