Phylum 
ECHINODERMATA 
Classes 
ASTEROIDEA 
( Starfishes) 
OPHIUROIDEA 
(Britile-stars) 
ECHINOIDEA 
(Sea-urchins) 
HOLOTHUROIDEA 
(Sea-cucumbers) 
CRINOIDEA 
(Feather-stars and Sea-lilies) 
200 
