from the GNU version of the Collaborative International Dictionary of English
- n. A peculiar sense organ found upon the exterior of most kinds of sea urchins, and consisting of an oval or sherical head surmounting a short pedicel. It is generally supposed to be an olfactory organ.
from The Century Dictionary and Cyclopedia
- n. Pl. sphæridia (-ä). In echinoderms, one of the numerous minute spheroidal bodies, rarely more than one hundredth of an inch long, which are found in nearly all sea-urchins upon the ambulacral plates, especially those nearest the mouth.
- n. The typical genus of the Sphæridiinæ, comprising mainly African species distinguished by the elongate scutellum and the visible pygidium. S. scarabæoides is an example.
Sorry, no etymologies found.