PLATE XIII/. 



Clypeaster scutiformis, f. 1 - Jf. 



1. Seen from aliove, denufled. 



2. Same seen from the actinal side. 



3. Section slinwinj; internal structure of the abactinal side. 



4. Section showing internal structure of the actinal side. 



Laganum depressum, /. 5-8. 



5. Seen from the abactinal side, denuded. 



6. Same from the actinal side, denuded. 



V. Seen from the abactinal side, covered with spines. 



8. Section to show internal structure, actinal floor removed. 



Fibularia australis, /. .'*, 10. 



9. Seen from the abactinal side, -l|4-. 

 10. Seen from the actinal side, -ijS,. 



{All Figs, not marked natural size.) 



