In biology, the cover is part of the body which is used as lid:

• At the Ascomycète S, a valve at the top of asque allowing to release the spores with maturity.
• At the Gastropodous S, the cover is a membrane cornea or limestone attached to the foot and which makes it possible to close again the entry of the shell. It is different from the épiphragme by its dynamic aspect.
• At the Insect S, plate which covers and protects the abdominal gills.
• At the Poisson S, osseous plate which closes hearing. This bone is often finished by one to three spines directed towards the back in most advanced fish

In Apiculture, the covers indicate the film of wax that the bees use to close the cells full with Miel, when this one with reached a sufficiently weak Hygrométrie for its conservation.

Note: In the everyday life, cover is synonymous with lid or protective pastille.

cover