The above-mentioned muscles are attached at their upper ends to the opercular valves, and at their lower ends to the basis.
The opercular Valves are large, owing to the form of the shell.
By the contraction of all three pairs of muscles, the opercular valves are held down with quite surprising force.
The opercular valves, or pieces placed so as to enclose the aperture.
The opercular has a facet for articulation with the hyomandibular.
They reach a considerable length before they are covered in by the opercular membrane.
The opercula of multivalve shells are composed of two or four pieces, which are called the opercular valves.
The posterior border of the hyoid arch is prolonged into an opercular fold.
This is the opercular flap which covers the gills that lie beneath.
They are small compared with the whole extent of the opercular membrane.
operculum o·per·cu·lum (ō-pûr'kyə-ləm)
n. pl. o·per·cu·lums or o·per·cu·la (-lə)
Something resembling a lid or cover.
The portions of the frontal, parietal, and temporal lobes covering the insula.
The mucus sealing the endocervical canal of the uterus after conception.
The attached flap in cases of torn retinal detachment.
The mucosal flap partially or completely covering an unerupted tooth.