THE STRUCTURE OP XENIA HICKSONI. 



187 



dceum is smooth and not folded in any way. Many of these epithelial 

 cells bear short cilia on the free surface, but among these are numerous 



DMF. 



G.C 



Fig. 1. — Semi-diagrammatic view of one half of a polyp which has been cut 

 along the dorso-ventral line. Only the bases of the tentacles are shown X 20. 



Fig. 2. — Transverse section through the lower third of the stomodseum 

 (about the level of the reference letter F in Fig. 1) X 80. 



D.M.F. Dorsal mesenterial filament on the edge of the dorsal mesentery ; 

 F. Flagella of siphonoglyph ; G.C. Gland cells of stomodseum ; L.M. Edge 

 of lateral mesentery (mesenterial filament absent) ; Mo. Mouth ; Si. Siphono- 

 glyph ; St. Stomodreum ; T. Tentacle; V.M. Edge of ventral mesentery 

 (mesenterial filament absent). 



