68 



CCELENTERATA AND 



Apical area with irregular plates. Pluteus without anal 

 rods. 



S. Drobachiensis. 

 Clypeastroids. 



Echinarachnius. Body nearly circular, very flat with 

 sharp, entire margin. Vent close to edge. Petaloid re- 





ECHINAR AC HNIUS . 



gion nlarked. Spines small, short, brown or reddish color. 

 Pluteus without anal rods. 



E. parma. 

 Spatangoids. 



Schizaster. Body heart-shaped, irregular, oval with 

 avenues on the upper surface. Mouth asymmetrical. Test 

 thin, fragile. Ambnlacral zones depressed and petaloid. 

 Pluteus with single median calcareous rod on the anal lobe. 



jS. fray His. 



