Habitat: Under rock slabs or pieces of coral rubble, living in or on coarse sand. Distribution: Occurs worldwide throughout the tropics. Natural History Notes: The urchin is never exposed; it may burrow or cling to undersurfaces of rock slabs. It is generally sedentary and moves very slowly even when disturbed. E. cyclostomus ingests organic material adhered to coarse sand and shell fragments. Adult individuals of this species and others in the family Echinoneidae do not possess a latern or teeth. Depth: 5-570m, most commonly at shallow depths Characteristics: The urchin is small, under 30 mm long. The spines are very short and range from whitish to light brown. The tube feet are conspicuously red, in narrow bands in the ambulacra, and make the urchin appear reddish. The test is white to light brown, with an ovoidal mouth in the center of the oral surface of the test and a large anus just posterior to the mouth.