operculum's Usage Examples:

Shell conical; slit or hole in anterior part of mantle; two symmetrical ctenidia; no operculum.

Spire of shell much reduced; two bipectinate ctenidia, the right being the smaller; no operculum.

Two osphradia present but no hypobranchial glands nor operculum.

op, Operculum.

No ctenidium, but a pulmonary cavity; operculum with an npophysis.

Shell semi-globular, with short spire; operculum calcareous, not spiral.

gonad occurs on the right c.p., Collar-canal, above which is side of the body only seen the operculum.

Shell spirally coiled; epipodial tentacles present; operculum thick and calcareous.

op., Operculum, or ventral lip. ov., Ovary.

Above the mouth is the lid (operculum), which varies in size from a small narrow process to a large heartshaped expansion.

Synonyms:

plate,

Antonyms:

cathode,