CURIANTHARIA. 



75 



pedoneine or "acontium" thus intersects as a rule both the ascending and the descending limb; only 

 at the base of those craspedonemes in which the filaments come to an end, is there no descending 

 limb to be found. 



The craspedonemes of the ciliated tract region are of two kinds. 



Textfigure 12. 



Kd. Tli 



Textfigure 14. 



Textfigure 13. 



Textfigure 15. Textfigure 16. 



Textfigures 12 16. 



Fig. 12. Section of a craspedoneme in the ciliated tract region of Ceriantheopsis amencanus. Fig. 13. Section of the most 

 aboral craspedoneme in the ciliated tract region of Pachyccrianthus matta. Fig. 14. Section of the craspedoneme-like cnido- 

 glandular tract of Pachycerianthus solitarhis. Fig. 15. Section of a so-called "acontium" (mucus-thread) of Arachnanthus oligo- 

 podus. Fig. 16. Section of a craspedoneuie in the craspedion region of Ceriantheopsis amcricanus. All sections from about 



the middle of the respective processes. 



i) Craspedonemes of the normal type which occur in many species usually in great numbers, 

 and have a filament limb on each side. They are found for example in C. membranaccus, P. multi- 



plicaius, maua, C. amcricamts (Textfig. 12). Often, as in C. mcmbranaccus, P. multiplicatus they are 



10* 



