Explanation of Plate VIII. 



Fig. 1. Ophiacantha {Ophialccca) nuttingii Ver. Ventral side of a 

 part of the disk and the base of an arm. X 8. 



Fig. la. The same specimen. Dorsal side. X 8. 



Fig. 2. Ophiomusium sculptum Ver. Dorsal side of a part of the 

 disk and the bases of two arms. X 8. 



Fig. 3. Ophiactis disparVer. Dorsal view of a portion of an arm, 

 near the base. X 15. 



Fig. 3a. The same specimen. Ventral side. X 15. 



Fig. 3d, 3c. The same specimen. Profile views of two more distal 

 rows of spines. X 15. 



Fig. 4, 4a. Astronyx lymani, Ventral and side views of three joints 

 from the proximal part of an arm. X 15. 



Fig. 4-d The same. Nearly side view of some of the more distal 

 joints, after treatment with potash, to show the plates. 

 The spines and hooks are removed. X 15. 



Fig. Ac. The same. Side view of some of the joints near the end of 

 the arm. Most of the hooks have fallen off. X 15. 



Fig. Ad. The same. Two ventral hooks, from the middle of the 

 arms. The smaller hooks have fallen off. Much enlarged. 



Fig. Ac. The same. A spine and two small hooks from the proximal 

 part of the arm. X 30. 



