Description or the Figures ix Platk II. 



All the figures in this Plate are drawn from polypes taken from the largest 

 living specimen. Fig 10 is constructed from a series of camera drawings taken 

 from different specimens. Figs 11 to 15 are drawn with the camera from single 

 sections. The magnifying power is indicated in diameters for each figure. 



Alphabetical List of References. 



f. Tentacle. 



g. Calyx. 



h. Cavity in caly.x-process. 

 i. Spicule. 

 k. Body-wall. 



l. Coenenchym, or fleshy body- 

 substance. 

 m. Mouth. 

 n. Stomach, 

 o. Mesentery. 



23. Retractor muscle. 



q. Protractor muscle. 



r. Short mesenterial filament. 



s. Long mesenterial filament. 



t. Ovum. 



V. Smaller canals of coenenchym. 



^v. Ectoderm. 



a*. Mesoderm. 



y. Endoderm. 



z. Thread-cell or nematocvst. 



Fig. 10.— A single polyi^e, with the part of the rachis from which it springs, 

 bisected longitudinally along its whole length ; the plane of bisection adopted 

 being the plane of symmetry : shows the whole structure of one of the polypes, 

 and the communication of its body-cavity with the canal system of the rachis, 

 X22. 



Fig. 11. — Transverse section through one of the tentacles at about the middle 

 of its length ; the section passing, on the right side, through the base of one of 

 the pinnules. Shows structure of tentacle and pinnule and arrangement of 

 thread-cells. X 70. 



Fig. 12.— Transverse section through a polype at the line BB in Fig. 10 ; passing 

 through the calyx, the bases of the tentacles, and the mouth. X 22. 



Fig. 13.— Transverse section through a polype at the line CC in Fig. 10, showing 

 the stomach and the mesenteries with their retractor muscles. X 22. 



Fig. 14. — Transverse section through a polype at the line DD in Fig. 10, showing 

 the mesenteries with the retractor muscles, and the long and short mesenterial 

 filaments. X 22. 



Fig. 15. — Transverse section through the lower part of a polype at the line EE 

 in Fig. 10, showing the ova in sitit, the long mesenterial filaments, and the open- 

 ings of the coenenchvmal canals into the body-cavity of the polype. 



