264 



DR. J. F. GEM MILL ON CILIARY ACTION IN THE 



Text-figure 1. 



Diagram of lateral wall of stomodseum of Pleurobrachia, showing direction of 

 ciliary currents. 



M.O., mouth-opening ; F.O., funnel-opening. 



(For explanation see text.) 



Text -figure 2. 



Diagram of internal cavities of Tle%rohraclria (transverse or infundibular plane in 

 plane of paper). The arrow-heads in the walls of the cavities point in the 

 direction of the ciliary currents. 



1. Stomodseum. 2- Funnel. 3. Paragastric canal. 4- Tentacular canal. 

 5. Perradial canal. 6. Interradial canal. 7. A sub-sagittal canal. 8. A sub- 

 transverse canal. ,9. Adradial canal. 



