Dictionary.net

Upon or above the notochord; - applied esp. to a vertebral column which develops upon the dorsal side of the notochord, as distinguished from a perichordal column, which develops around it.

Upon or above the notochord; - applied esp. to a vertebral column which develops upon the dorsal side of the notochord, as distinguished from a perichordal column, which develops around it.

Upon the notochord ; vertebrae in which the ventral cartilaginous portions are almost completely suppressed.

[Greek] Upon the notochord; appl. vertebrae in which ventral cartilaginous portions are almost completely suppressed; appl. upper lobe of caudal fin in fishes.