(noun; plural ambulacra
; Latin ambulare
, to walk): 1. (Arthropoda
) The adhesive disc
of hooks that terminate the tarsus
2. (Arthropoda: Insecta) The walking leg.
3. (Echinodermata) Plates with pores forming the test, arranged in 5 or more rows, where the podia of the water-vascular system project to the exterior.