PLATE IV. 



Fig. 1. Hemipliolis élongato^ Dorsal view of the skeleton of two oral 



angles and the first two vertebrae, x 16. 

 rig. 2. AniiihipJiolis kochii. Dorsal view of the skeleton of two oral 



angles, x 18. 

 Fig. 3. OpMophragmus japonicus. Dorsal view of the skeleton of two oral 



angles, x 20. 

 Fig. 4. AmpJdura trachydisca. Dorsal view of the skeleton of two oral 



angles, x 8. 

 Fig. 5. Ophiocentrus verticillatus. Dorsal view of the skeleton of two oral 



angles and one arm base. xl3. 

 Fig. 6. OpMothrix nereidina. Dorsal view of the skeleton of two oral 



angles and one arm base, with the radial shields turned up, i.e. in 



ventral view. X 10. 

 Fig. 7. Opldolhrix horeana. Doi'sal view of the skeleton of two oral 



angles and one arm base, x 10. 

 Fig. 8. OpJdotlida dance. Dorsal view of the skeleton of two oral angles 



and one arm base, x 10. 



