ClipArt ETC
"Echinus gracilis. a, ambulacral plates; b, poriferous zone; c, interambulacral plates." — Encyclopedia Britannica, 1893

Echinus gracilis

"Echinus gracilis. a, ambulacral plates; b, poriferous zone; c, interambulacral plates." — Encyclopedia…

"Cidaris florigemma, with spine, a, and single ambulacral plate, magnified, b, (after Wright; Coral Rag." — Encyclopedia Britannica, 1893

Fossil Echinidea

"Cidaris florigemma, with spine, a, and single ambulacral plate, magnified, b, (after Wright; Coral…

"Stomechinus intermedius. a, portion of ambulacral area; b, poriferous zones; c, two interambulacral plates; d, primary tubercles." — Encyclopedia Britannica, 1893

Stomechinus intermedius

"Stomechinus intermedius. a, portion of ambulacral area; b, poriferous zones; c, two interambulacral…