Amphioxus \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.

Source: Webster's Revised Unabridged Dictionary (1913)