(n.pl.) 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.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). Leptocardia. Retrieved September 20, 2026, from http://smartdefine.org/leptocardia/definitions/2027440 |
| Chicago | Webster's. 2011. "Leptocardia" http://smartdefine.org/leptocardia/definitions/2027440 (accessed September 20, 2026). |
| Harvard | Webster's 2011, Leptocardia, Smart Define, viewed 20 September, 2026, <http://smartdefine.org/leptocardia/definitions/2027440>. |
| MLA | Webster's. "Leptocardia" 27 May 2011. Web. 20 September 2026. <http://smartdefine.org/leptocardia/definitions/2027440> |