opercular valve
Movable plate in orifice of cirriped shell, one of pairs of scuta and terga joined to sheath by opercular membrane. [Moore and McCormick, 1969] [Martin, 2005].
One of 2 or 4 movable plates occluding aperture in sessile barnacles [McLaughlin, 1980].
(Subclass Cirripedia):
Barnacle shell feature: in unstalked barnacle, calcareous plate forming part of closing apparatus (operculum). Consists of symmetrical forms of both scuta and terga, in asymmetrical forms of single (movable) scutum and single (movable) tergum. Attached to inner wall (sheath) of shell by opercular membrane [Stachowitsch, 1992].

Crustacea glossary. . 2011.

Look at other dictionaries:

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