The term, velum, derived from Latin "velum", meaning a "sail", "curtain," "awning" or "veil", has several quite separate meanings in
* the locomotory and feeding organ provided with
ciliafound in the larval stage called the veligeror "velum-bearing" stage of bivalves, such as mussels and oysters; also a delicate membrane found on certain Protists.
* the circular membrane around the cap of a sea jelly or medusa, of class
Hydrozoa, which helps with propulsion
* the veil-like membrane of immature
mushrooms extending from the margin of the cap to the stem and torn by growth, revealing the gills of a mature sporophore; in a mature mushroom, the remains of the velum may form an "annulus" or ring around the stem, familiar from common button mushroomsand sometimes on the margin of the cap.
soft palatebehind the hard palate
superior medullary velum
* a thin flap of tissue completely or partially covering the adaxial wall of the
sporangiumin species of Isoetes
* Velum is also a common misspelling of
vellum, calfskin (or sometimes the skins of other animals) that is similar to parchmentand that is used as medium for writing, book printing, and book binding. Today, leatherette, leather, clothor paperare more commonly used, but vellum is still used occasionally.
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