PLATE I. 



Fig. 1. OpModera anisacantJia. Dorsal view of the skeleton of two oral 



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



ventral view. X 6. 

 Fig. 2. Ditto. Inner articular surface of a vertebra near disk, x 6. 

 Fig. 3. Ditto. Outer articular surface of the same. X 6. 

 Fig. 4. Opldomyxa ausiralis. Dorsal view of the skeleton of two oral 



angles and one arm base of a young specimen, with the radial 



shields turned up, i.e. in ventral view. X 30; 

 Fig. 5. Ditto. Inner articular surface of a vertebra near disk, x 30. 

 Fig. 6. Ditto. Outer articular surface of the same, x 30. 

 Fig. 7. Ditto. Dorsal view of the skeleton of two oral augles. x 15. 

 Fig. 8. OpMoliyalus gotoi. Dorsal view of the skeleton of two oral angles 



and the first vertebra, x 15, 

 Fig. 9. Ophiostiba JddeJcii. Dorsal view of the skeleton of two oral angles. 



Xl5. 

 Fig. 10. OpMosmilax mirahilis. Inner articular surface of a vertebra near 



disk. X 40. 

 Fig. 11. Ditto. Outer articular surface of the same. x40. 

 Fig. 12. Ditto. A long arm spine, with two series of booklets, x 40. 

 Fig. 13. Ditto. A short arm spine, with one main and one supplementary 



booklet. X 40. 

 Fig. 14. Asteronyx loveni. Dorsal view of the skeleton of two oral angles 



and one arm base of a young specimen, with the radial shields 



turned up, i.e. in ventral view, x 20. 

 Fig. 15. Ditto. Inner articular surface of a vertebra near disk, x 20. 

 Fig. 16. Ditto. Outer articular surface of the same. x20. 



