Plate III. 



VifrolJiila JhiiUs Ij. P. oS. 



Fig. 1. One of 8. C. M. Sp. No, 228, found attached to a dead coral. 



From Okinopé. Nat. size. 

 Fig. 2. S. 0. M. Sp. No. 231, attached to a worni-tul)e. From off Inatori. 



Nat. size. 

 Fig. 3. Part of a moderate-sized stauractinic dermal ia. 300 x . 

 Fig. 4. Part of the ]iaratangential cross of a hypodermal pentactin. 300 x . 

 Fig. ;■). Oxyhexaster. 300 x . 

 Fig. G. Microdiscohexaster, the only form of discohexaster present in thi^ 



species. 300 x . 

 Fig. 7. Part of a stained transverse section tlu-ongh tho body of Sp. No. 



231. Exciirrent canal opening freely into the gastral cavity. 3 x . 

 Fig. 8. Part of a longitudinal section of the same specimen. Above, 



the oscular margin. About 2.5 x . 

 Fig. 9. Surface view of the stained wall of S. C. M. Sp. No. 433 ; aliove, 



oscular margin. Seen from the gastral side. Al)out 50 x . 

 Fig. 10. Same, seen from the dermal side. About 50 x . 

 Fig. 11. Showing the gradual transition of memhrana refici(Iari-'< (above) 



into trabecule (below) near the oscular margin. From a hfema- 



toxylin preparation. 300 X. 

 Fig. 12. A small group of archa='ocytes lying on the chamber-wall. From 



a borax-carmine [)reparation. 1000 x . 

 Figs. 13-16. Stages in the development of a larva, from sections of Sp. 



No. 231. Stained with borax-carmine. 150 x. 

 Fig. 17. Stauractinic spicules from the larval stage of fig. IG. The lower 



figure, in side view. 440 x . 

 Fig. 18. Section of a developing larva, somewliat more advanced than that 



of fig. 16. Stained with h;\3matein-alum. 300 x . 

 Fig. 1!). The outer layer of flagellated cells, seen surface on. From the 



same larva. 300 x . 

 Fig. 20. A fully developed larva in optical section, but with tin? peripherally 



situated spicules of one side drawn in. 150 x . 

 Fig. 21. Longitudinal section of a, fully developed larva, stained with 



h;ematein-alum, 300 x . 

 Fig. 22. Pasidictyonalia, joined below to the small-meshed attachment ])late. 



100 X. 



