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Webster 1913 Edition
Prosobranchiata
‖
Prosˊo-branˊchi-a′ta
,Noun.
pl.
[NL., fr. Gr. [GREEK] forward, further + [GREEK] a gill.]
(Zool.)
The highest division, or subclass, of gastropod mollusks, including those that have the gills situated anteriorly, or forward of the heart, and the sexes separate.