154 



Fig. 17. Side view of a mesentery from a polyp of about 

 20 mm, in length, showing the coiled loop of the mesenterial 

 filament, generative mass and arrangement of the muscular 

 fibres. The filament is reversed so that the upper end is 

 actually the more deeply situated in the corallum. The 

 sperm acini contain ripe spermatozoa and on the inner side 

 are seen three ova. To the right of the figure the clumped 

 attachments of the muscular fibres to the corallum are seen. 



Figs. 18-21. Views of four South African specimens of 7^ 

 pavon/'nii/n from the side to show the general shape, accretion 

 lines, wings, etc. 



Figs. 2 2-T,4. Various corallites of -F. ritbrum from side view 

 to show the variations in the shape of the corallum. 



[Published 2ist November, 1902.] 



