Rotifera (L. rota, a wheel; fero, I bear). The name of a class of infusorial animalcules, characterized by the vibratile and apparently rotating ciliary organs upon the heads.

Rhodospermes. The red-coloured sea-weeds.

Serrated (L. serra, a saw). Toothed like a saw.

Sessile. Attached by a base.

Silicious (L. silex, a flint). Flinty.

Setæ. Bristles, or similar parts.

Spicula (L. spiculum, a point or dart). Fine-pointed bodies, like needles.

Tuberculate. Warty, or carved with small rounded knobs.

Testacea (L. testa, a shell). Molluscs with a shelly covering, as the Oyster, Whelk, &c.