IIOLOTHUKIOIDEA. 207 



EXPLANATION OF PLATES. 



List of Reference Letters. 



a., anus ; ant., anterior end ; dors, p., dorsal papillae ; ?'., inter-radial ; m., mouth ; p.b., pedicels of the bivium ; 

 p.})., posterior prolongations of radials ; p.t., pedicels of the trivium; r., radial ; s., spire of table. 



PLATE I. 



Fig. 1. Tentacles of Synapta striata, Sluiter, from life. 



Fig. 2-4. Spicules of Cucwmaria turbinata (Hutton). 



Fig. 5. Calcareous ring of same. 



Fig. 6. Side view of C. turbinata ; three times natural size. 



Fig. 7. Top view of a complete table of Thyone fusus, var. papuensis, Theel. 



Fig. 8. Top view of an incomplete table of same. 



Fig. 9-10. Spicules of Thyone sacellus (Selenka). 



Fig. 1 1 . Calcareous ring of Thyone (?) fusca, n. sp. 



Fig. 12-13. Spicules of same. 



Fig. 14. Calcareous ring of Thyone (?) hornelli, n. sp. 



Fig. 15-16. Spicules of same. 



Fig. 17. Calcareous ring of Thyone (?) calcqrea, n. sp. 



Fig. 18-20. Spicules of same. (Fig. 19 is side view of table.) 



PLATE II. 



Fig. 21. Colochiins guadrangularis, var. mollis, nov. ; natural size, from life. 



Fig. 22. Side view of spicule of Phyllophorus cebuense (Semper). 



Fig. 23. Underneath view of same. 



Fig. 24. Calcareous ring of Phyllophorus cebuense. 



Fig. 25. Calcareous ring of Actinocucuniis donnani, n. sp. 



Fig. 26-28. Spicules in general integument of same. 



Fig. 29-30. Spicules of tube feet of same. 



Fig. 31. Side view of Havelockia herdmani, n. gen. et sp. ; twice natural size. 



Fig. 32. Top view of " table " in the general integument of same. 



Fig. 33. Side view of " table " in the general integument of same. 



Fig. 34. Top view of " table " of the papilla; of same. 



Fig. 35. Calcareous ring of Havelockia herdmani. 



