Aristotle's lantern is found in .........

Which of the following is a consistent group?

Basket star belongs to which class?

Absence of excretory organs,great power of regeneration,and exclusively marine animals belong to the phylum:

Sea lilies are the members of which class?

$A$ : Echinoderms are the only radially symmetrical animals with true coelom.
$R$ : Echinoderms have secondarily adapted to radial symmetry.