EXPLANATION OF PLATE LiV. 

 ECHINOIDE A. 



Stephanocidaris bisjnuosa. 

 Fig. L — Side view. Slightly reduced. 



OP EilU ROI DEA. 



AstrojJorpa australiensis . 

 Fig. 2. — Abactinal view, x 2-^. 



Astrothrombus rugosus. 

 Fis. 3. — Abactinal view of disc and bases of the five arms, x 6. 



