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Webster 1913 Edition
Opisthobranchiata
{ ‖
O-pisˊtho-bran′chi-a
,O-pisˊtho-branˊchi-a′ta
, }Noun.
pl.
[NL., from Gr.
ὄπισθεν
behind + [GREEK] gills.] (Zool.)
A division of gastropod Mollusca, in which the breathing organs are usually situated behind the heart. It includes the tectibranchs and nudibranchs.