1) Class 2) Class holothuroidea 
The holothuroidea are the sea cucumbers order of Echinoderms. The body is elongated and appears worm-like. Skeletal plates are minute and imbedded in the fleshy body wall. There are no spines. The mouth is at one end of the body, the anus at the other. Feeding is carried out by tube feet near the mouth.
[n] - class of echinoderms including the sea cucumbers
class Holothuroidea noun class of echinoderms including the sea cucumbers