ECHINODERMATA 33 



Order DENDROCHIROTA 



Cucumaria; Thyone; Echinocucumis; Psolus; 



Phyllophorus 

 Order MOLPADONIA 



Molpadia 

 Order APODA^ 



Synapta; Leptosynapta; Labidoplax 



Class ECHINOroEA 



Sub-class PERISCHOECHINOroEA 



Order CIDAROIDA (sea urchins) 

 Cidaris 

 Sub-class EUECHINOIDEA 



Super-order DIADEMATACEA (sea urchins) 



Order DIADEMATOIDA 



Diadema; Centrostephaims 

 Order ECHINOTHURIOIDA 



Phormosoma; Areosoma 

 Super-order ECHINACEA (sea urchins) 



Order HEMICroAROmA 



Salenia 

 Order PHYMOSOMATOIDA 



Stomopneustes 

 Order ARBACIOIDA 



Arbacia 

 Order TEMNOPLEUROIDA 



Temnopleunis ; Tripneustes (=Hipponoe); 



Toxopneustes; Mespilia; Sphaerechinus; Lytechinus; 



Pseudocentrotus 

 Order ECHINOroA 



Echinus; Echiiwmetra; Strongylocentrotus ; 



Psammechinus; Paracentrotus; Hemicentrotus: 



Anthocidaris ; Heliocidaris 



Super-order GNATHOSTOMATA 



Order HOLECTYPOIDA 



Sub-order Echinoneina 



Echinoneus 

 Order CLYPEASTEROIDA (sand-dollars, cake 

 urchins) 

 Sub-order Clypeasterina 



Clypeaster 

 Sub-order Laganina 



Laganum; Echinocyamus 

 Sub-order Scutellina 



Me Hit a; Echinarachnius ; Dendraster 

 Sub-order Rotulina 



Rotula 



Super-order ATELOSTOMATA 



Order NUCLEOLITOIDA 



Neolampas 

 Order CASSIDULOIDA 



Cassidulus 



' See Gymnophiona, p,41. 



