PLATE XV. 



Fig. 1. Siderastraea galaxea Blainv., specimen with polyps half expanded, natural size. 



Fig. 2. Siderastrsea galaxea Blainv., part of specimen fully expanded, natural size. 



Fig. 3. Siderastrasa galaxea Blainv., a polyp contracted, magnified. 



Fig. 4. Siderastraea galaxea Blainv., polyp partly contracted, in prgfile, magnified. 



Fig. 5. Siderastraja galaxea Blainv., part of disc contracted, magnified. 



Figs. 6, 7. Siderastroea galaxea Blainv., polyps fully expanded, showing the peculiar bilobate tentacles. 

 No note was found accompanying the figures to explain the difference in size of the tentacles 

 in the two figures ; possibly No. 7 represents Siderastraea galaxea, and No. 6, Siderastraea siderea. 



Fig. 8. Siderastrsea galaxea Blainv., specimen divested of animal matter, natural size. 



Fig. 9. SiiTerastraea galaxea Blainv., groups of calicles, magnified, multiplying by gemmation. 



Fig. 10. Siderastraea galaxea Blainv., large calicle in process of division. 



Fig. 11. Siderastraea gala.vea Blainv., vertical section, showing the synapticula and dissepiments, magni- 

 fied. 



Fig. 12. Siderastraea galaxea Blainv., horizontal section, showing the synapticula extending across the 

 interseptal chambers as in Fungidac (see figs. 15 and 17). The following figures of Fungia 

 integra Dana, from the Pacific Ocean, were given on this plate to show by direct comparison 

 the Fungian character of siderastraea. 



Fig. 13. Fungia integra Dana, part of a specimen, natural size. 



Fig. 14. Fungia mtegra Dana, vertical section, showing sjmapticula, natural size. 



Fig. 15. Fungia integra Dana, horizontal section, showing synapticula extending across the chambers. 

 (Compare with fig. 12.) 



Fig. 16. Fungia integra Dana, section through centre, natural size. (Compare with fig. 11.) 



Fig. 17. Fungia integra Dana, part of fig. 15, magnified. 



Fig. 18. Fungia integra Dana, outline of part of specimen, natural size. 



