Ophiuroidea (OPHIURIDE, SNAKE-STARS, BRITTLE-STARS)

Echinoderms, with stellate bodies, consisting of a central disk and five slender-jointed, flexible arms, that do not contain prolongations of the viscera, and whose ambulacral grooves are covered up by plates, so that the sucker-feet stick out at the sides. The larvæ are plutei. There is no anus. Some are Ophiuroidea ( Ophiotriz fragilis ) . viviparous. The arms in some forms are dichotomously branched into numerous branchlets.