From ZooTerms (Dictionary of Invertebrate Zoology)
Jump to: navigation, search
radial (noun; Latin radial, ray): (Echinodermata) 1. In Crinoidea, any proximal, undivided plate or ray bearing an anal plate. 2. In Asteroidea, a prominent ossicle on the surface in line with the mid-line of the arm; part of the primary surface. 3. In Echinoidea, the ambulacrum.