NOTES ON THE BIOLOGY OF THE FIVE-LUNULED SAND DOLLAR

Abstract

When removed from the sand the animal buries itself immediately by simply advancing into the sand until covered again. The function of the lunules is unknown. Sand positively does not pass through them in the burying process. Podia are limited to the ambulacral furrows. The method of feeding could not be determined. Carmine grains and crushed bits of plankton stained or not were never moved, regardless of where placed, nor was there evidence of ciliary action anywhere. Intestinal contents consisted of minute organisms without any sand or evidence of larger organisms.