a. Zool. [f. L. ad to, at + AMBULACRA + -AL.] Adjacent to the ambulacra, in sea-urchins and other echinoderms.
1872. Nicholson, Palæont., 113. At their outer extremities the ambulacral ossicles are articulated by the intervention of the ‘adambulacral plates,’ with plates belonging to the external or integumentary skeleton.
1882. Sladen, in Jrnl. Lin. Soc., XVI. No. 91, 204. The ambulacral spines that form the comb belonging to the first adambulacral plate have their bases arranged in a semicircular curve.
