248 THE VOYAGE OF H.M.S. CHALLENGER. 



Fig. 11. Flabellum alabastrum. Soft parts seen in a vertical section of one lateral half 

 of the coral. 



M. Mouth leading to the stomach. 1, 2, 3 Mesenteries of those orders, 



with their attached filaments, muscles, and ova. The positions of 



the margins of the septa of those orders are represented by fine curved 



dark lines. The wall of the corallum is seen in section in situ. 



Fie. 12. Arrangement of the tentacles with regard to the septa in Flabellum jcqionicum. 



1, 2, 3, 4 Primary, secondary, tertiary, and quarternary septa, at the inner 



margins of which are seen the corresponding peculiarly-shaped tentacles. 



