DR. HUBERT LYMAN CLARK‘S large work, "Echinoderms from Australia", was reviewed in Nature of September 24, 1938. That review and the obituary notice of Dr. Clark in Nature of September 20 ...

Echinoderm means “spiny skin” in Greek ... The movement of the tube feet is controlled by a water vascular system, a series of fluid-filled canals and chambers connected to the tube feet.