Plate VI. 



Transverse sections of the body-wall figs, i, 3, 5 in the region of the oesophagus; figs. 2, 4 in the enido- 

 glandular tract of the filaments, fig. 6 in the hyposulcus region (Magnification ■».', Reichert's "Austria"; 

 the figures drawn on the level of the microscope's foot; fig. 1 same magnification but with drawn out 



tube. Entoderm not drawn in figs. 1 — 4). 



Fig. 1 of Isozoanthus bulbosus (from Ingolf Exp. St. 104). 



— 2 - arborescens (from Mortsund, Nordgaard). 

 3 - multinszilosus (from Ingolf Exp. St. 51). 



— 4 - — magninsulosus. 



— 5 - - - 



— 6 - ingolfi (from Ingolf Exp. St. 27). 



