Velum
The
velum, derived from
Latin velum, meaning a "sail", "curtain," "awning" or "veil," has several quite separate meanings in
biology:
*the locomotory and feeding organ provided with
cilia found in the
larval stage called the
veliger or "velum-bearing" stage of
bivalves, such as
mussels and
oysters; or a delicate membrane found on certain
Protists.
*the circular membrane round the cap of a
sea jelly, or
medusa of class
Hydrozoa.
*the veil-like membrane of immature mushrooms extending from the margin of the cap to the stem and is 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
mushrooms, and sometimes on the margin of the cap.
*the
soft palate behind the
hard palate.
*Velum is also a common misspelling of
vellum, pigs skin with which books were once covered. Today,
Leatherette,
leather,
cloth or
paper are more commonly used.
