DESCRIPTION OF PLATES XI. and XI r. 



Fig. l. — Diagrammatic representation of a sextant in Actinia. — (a) 

 Primary, (6) Secondary, (c) Tertiary, and (d) Quaternary septa. 



Figs. 2 & 8. — Fluted organ of A. mesembry anthem um (sec text). — (a) Sep- 

 tum, (c?) White spots. 



Fig. 3. — Transverse section of a sextant of A. mesembry anthemum, made 

 half-way down. 



Fig. 1. Ditto, made close under the disc. 



Fig. 5. — Base of ditto. 



Fig. *! -Tertiary septum of A. mesembryanthemum, with eggs: craspeduai 

 cut away ; fluted organ in wavy line. 



Fig. 7. Quaternary septum of 8. parasitica ; early ovarian stage (Sep- 

 tember). No craspednm carried by this septum, fluted organ seen 

 lifted up. 



Fig, 9. Quaternary septum of /'. crassicornis ; craspednm at foot ai d 

 edging septum, and followed by fluted organ rnnning to back of 

 stomach wall ; eggs cover septum. 



Fig 10. Eggs of S. parasitica. 



Fig. II. Quaternary septum of S. parasitica-; advanced ovarian stage 

 (November) ; fluted organ removed. 



Fig. 12". — Fluted organ in S. parasitica, showing keel-like process. 



Fig. 13 Marks seen through disc of A. mesembryanthemum (see text). 



Fig. 11. — Relative shapes of the four septa in ditto. 



Fig. 15. — Marks seen through disc of 8. parasitica. 



