48 



THE VOYAGE OF H.M.S. CHALLENGER. 



they have no definite arrangement, and I have been unable to find such in horizontal 

 sections. Sometimes what appeared to be an additional mesentery proved to be an 

 apparent confluence of the entoderm of the stomodgeuni with that of the wall of the oral 

 cone. In such cases I was unable to trace any continuity between the mesoglcea of the two 

 areas. In a series of horizontal sections passing from the mouth to the base of the stomo- 

 djeum the outline of the latter is most irregular. The mouth is much elongated, 



Fig. 12. Fig. 1.3. 



Figs. 12, 13, and 14. — Horizontal sections of Cladopathcs plumosa. 



Fig. 12. — Section through the upper part of the oral prominence. The figures indicate the position of the mesenteries. Numbers 



2 and 5 are those which ultimately occupy the transverse axis. 

 Fig. 13. — Section at a lower level than fig. 12, showing the change in position of mesenteries 1 and 4 due to the insertion of the 



sagittal tentacles. 

 Fig. 14. — Section near the base of the stomodajum, showing the transverse mesenteries continuous with those of the gonozooids. 



but the elongation does not take place in one plane as is usual, nor does it appear that 

 a pair of mesenteries invariably support each extremity as in other Antipathidse. 

 Fig. 12 shows the arrangement in the upper portion of the stomodasum. The mesenteries 

 are numbered consecutively, following the order of the primary mesenteries in Leiopathes 

 (fig. 1G). That is to say, numbers 2 and 5 represent the mesenteries situated in the 



