Zool. [f. L. clype-us (= clipeus) round shield + Gr. ἄστηρ star.] A genus of echinoid Echinoderms, allied to the common sea-urchin, but having mouth and vent both below.
Hence Clypeastroid a. and sb.
1836–9. Todd, Cycl. Anat., II. 33/2. In Clypeaster the shell is divided interiorly by vertical calcareous partitions.
1877. Huxley, Anat. Inv. Anim., ix. 574. The flattened Clypeastroid, Scutella.
