EXPLANATION 0^ PLATE LIIL 

 OPHIUROIDEA. 



Ophiopristis axiologus. 

 Fig. L — Actinal view, x 15. 

 Fig. 2. — Abactinal view, x 15. 

 Fig. 3. — Side view of three arm-joints, x 15. 

 Ophiothrix aceatra. 



Fig. 4. — Abactinal view of disc and arm bases, x 7, with some of 



the disc-stumps and spinelets more highly magnified. 

 Fig. 5. — Venti'al view of three arm-joints, x 7. 



