资料来源 : Webster's Revised Unabridged Dictionary (1913)

Sphaeridium \Sph[ae]*rid"i*um\, n.; pl. {Sph[ae]ridia}. [NL.,
   fr. Gr. ??? a sphere.] (Zo["o]l.)
   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.