ClipArt ETC
"Sponge spicules. 1, Monaxon; 2, triod; 3, triaxon; 4, tetraxon; 5, anchor; 6, polyaxon; 7, a kind of amphidisc." -Thomson, 1916

Sponge Spicules

"Sponge spicules. 1, Monaxon; 2, triod; 3, triaxon; 4, tetraxon; 5, anchor; 6, polyaxon; 7, a kind of…