62 CXELENTERATA AND 



I. Color reddish, madreporic body dull in color. Free 

 larvae take the form of brachiolaria. 



A. vulgaris. 



II. Color brownish, madreporic body bright red or more 

 often orange. 



A. Forbesii. 

 b. Six rays. 

 Spines scattered, large, slight constriction between 

 arms and disk. 



A. polaris. 

 Leptasterias. Body stellate, five-rayed with prominent 

 scattered spines ; color white or light gray. Young vivi- 

 parous, attached by a cord on the oral region. 



L. tenera. 







t;;.^-^ 





Cribrella. Body smooth, stellate, five rayed, covered 

 with short spines and spine waits, porous integument. 

 Lateral spines small and inconspicuous. Two rows of 



