PLATE XVI. 



Fig. 1. Ophioglypha robusta (Ayr.); part оГ oral side, showing ab- 

 normal development of papillæ between the inner pores, ^"/i. 



— 2. Spine from the dorsal paxillæ of Pteraster militaris (O. F. 



Miill.j. ^'4u 



— 3. Spine from the dorsal paxillæ of Pteraster piiluillus M. 



Sars. *^'i. 



— 4. Part of the wall of the stomach of Ctenodiscus crispatus, showing 



the spicules in their natural position. ^'^■^Ii. 



— 5. Part of dorsal skin of Ctenodisciis crispatiis, showing radia- 



ting muscles between the paxillæ. '^^/i. 



— 6. Spine of Poraniomorpha tiimida (Stuxb.j, from the dorsal 



side. '^■''*'/i. 



— 7. Spine of Poraniomorpha tiimida (Stuxb.), from the oral 



side. 2io/i_ 



