\Am`phi*ox"us\, n. [NL., fr. Gr. ? + ? sharp.]
(Zo["o]l.)
A fishlike creature ({Amphioxus lanceolatus}), two or three
inches long, found in temperature seas; -- also called the
{lancelet}. Its body is pointed at both ends. It is the
lowest and most generalized of the vertebrates, having
neither brain, skull, vertebr[ae], nor red blood. It forms
the type of the group {Acrania}, {Leptocardia}, etc.