'Leptocardia' definitions:

Definition of 'Leptocardia'

From: GCIDE

Leptocardia \Lep`to*car"di*a\ (l[e^]p`t[-o]*k[aum]r"d[i^]*[.a]), n. pl. [NL., fr. Gr. lepto`s small + kardi`a the heart.] (Zool.) The lowest class of Vertebrata, including only the Amphioxus. The heart is represented only by a simple pulsating vessel. The blood is colorless; the brain, renal organs, and limbs are wanting, and the backbone is represented only by a simple, unsegmented notochord. See Amphioxus. [Written also Leptocardii.] [1913 Webster]