Ve*lel"la (?), n. [NL., dim. from L. velum a veil, a sail.] Zool.
Any species of oceanic Siphonophora belonging to the genus Velella.
⇒ These creatures are brilliantly colored and float at the surface of the sea. They have an oblong, disklike body, supported by a thin chitinous plate, from which rises a thin diagonal crest which acts as a sail. The feeding and reproductive zooids hang down from the under side of the disk.
© Webster 1913.