operculum การใช้

• The posterior extremity is caducous, and destitute of an operculum.
• The operculum serves some of the same functions as an epiphragm.
• The entire operculum is paucispiral, and has an eccentric nucleus.
• The operculum is circular, multispiral, with a central nucleus.
• The operculum is yellowish, ovate and has an apical nucleus.
• The interior of the operculum is ovate, withan apical nucleus.
• The operculum is castaneous within, with four rapidly increasing whorls.
• Gills are tissues which consist of threadlike protein structures called operculum.
• The operculum and preopercle may or may not have spines.
• The adult animal has a very large, solid and heavy operculum.
• The group is distinguished by having spore operculum falls off.
• The dark edge of the operculum also fades with age.
• The operculum of juveniles, however, is spirally marked.
• An inconspicuous dusky spot is usually seen on the operculum.
• Juveniles are generally lighter in colour, also possessing five dark operculum.
• Most species have a dorsal operculum has a terminal nucleus.
• The operculum only, and the edge of the mantle are yellowish.
• The head end of the larval case is closed by an operculum.
• The operculum of the case is covered with small pebbles.
• The oval operculum is flat within, with four whorls.