12 JOSEPH A. CLUBB. 



m. f . mesenterial filaments, 

 nig. mesogloea. 

 m. 1. muscle lamellfe. 



oe. oesophagus. 



oe. in. cesophageal invagination of embryo, 

 ov. ova. 



p. pseudoacroragus. 

 p. b. m. parieto-basilar muscle. 



s. siphonoglyphe. 

 sph. sphincter. 



t. tentacle, 

 tes. testis. 

 v. verrucse. 

 x. zooanthellae. 



PLATE I. 



FIG. 1. Parantheopsis cruentata (Couthouy). Radial section of the upper part of the body-wall, passing 



through a pseudoacroragus. 



FIG. 2. Paractis polaris, sp. n. Drawing of the specimen (natural size). 

 FIG. 3. P. polaris. Radial section of upper part of body-wall and sphincter muscle. 

 FIG. 4. P. polaris. Portion of sphincter muscle more highly magnified. 

 FIG. 5. P. polaris. Horizontal section through the body-wall and mesenteries in connection with 



oesophagus. 

 FIG. 6. P. polaris. Transverse section of the wall of a tentacle. 



PLATE II. 



FIG. 7. Paractis papaver (Drayton). Eadial section through the upper part of the body-wall and sphincter 



muscle. 



FIG. 8. P. papaver. Transverse section of wall of a tentacle. 

 FIG. 9. P. papaver. Section through ovary. 

 FIG. 10. P. papaver. Section of mesenterial filament. 

 FIG. 11. P. papaver. Section through portion of a mesentery. 

 FIG. 12. Cystiactis anlarctica, sp. n. Drawing of specimen (natural size). 

 FIG. 13. C. anlarctica. Section of upper part of body-wall, passing through sphincter muscle. 

 FIG. 14. C. antarctica. Horizontal section through body-wall and mesentery, with ovary. 

 .FiG. 15. C. antarctica. Section of ovary more highly magnified. 



PLATE HI. 



FIG. 16. Crilrina octoradiata (Carlgren). Radial section through upper part of body-wall, sphincter and 



opening to ' brood ' chamber. 



FIG. 17. C. octoradiata. Section through wall of a tentacle. 

 FIG. 18. C. octoradiata. Horizontal section through body-wall and mesenteries, including the directive 



mesenteries. 



FIG. 19. C. hermaphroditica (Carlgren). Horizontal section through body-wall and fertile mesenteries. 

 FIG. 20. C. hermaphroditica. Section, more highly magnified, of genital gland. 

 FIG. 21. C. hermaphroditica. Section through wall of tentacle. 

 FIG. 22. Rhodactinia crassitornis (0. F. Miiller). Reproduction from a photograph of a living specimen, 



illustrating an extreme reduction of the size of the tentacles. 

 FIG. 23. R. crassicornis. Radial section through the sphincter of a ' Discovery ' specimen. 



