Search the Dictionary

An extensive artificial group of invertebrates, having all the parts arranged radially around the vertical axis of the body, and the various organs repeated symmetrically in each ray or spheromere.

he grand divisions of the animal kingdom. By many writers it was formerly included in the Radiata. [Written also Echinoderma.]

Belonging to the Radiata.

Belonging to the Radiata.

-- Electric ray, or Cramp ray, a torpedo. -- Starry ray, a common European skate (Raia radiata). -- Sting ray, any one of numerous species of rays of the family Trygonidæ having one or more large, sharp, barbed dorsal spines on the whiplike tail. Called also stingaree.

Anything resembling such a nail in shape. He wears on his head the corona radiata . . . ; the spikes that shoot out represent the rays of the sun. Addison.

anged in rays like those of a star; stellate. Starry ray (Zoöl.), a European skate (Raita radiata); -- so called from the stellate bases of the dorsal spines.

Situated under a zone, or zona; -- applied to a membrane between the zona radiata and the umbilical vesicle in the mammal embryo.

where the sun sets; the west. Sunset shell (Zoöl.), a West Indian marine bivalve (Tellina radiata) having a smooth shell marked with radiating bands of varied colors resembling those seen at sunset or before sunrise; -- called also rising sun.

s to the cell wall of an ordinary cell. See Ovum, and Illust. of Microscope. (b) The zona radiata. -- Zona radiata Etym: [NL.] (Biol.), a radiately striated membrane situated next the yolk of an ovum, or separated from it by a very delicate membrane only.