Plate VI. 



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

 glandnlar tract of the filaments, fig. 6 in the Inposulcus region (Magnification 4/, Reichert's "Austria"; 

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



tube. Entoderm not drawn in figs, i — 4). 



Fig. I of Isozoantlms bulbosus (from Ingolf Exp. vSt. 104). 



— 2 - — arborcsccus (from Mortsnnd, Nordgaard). 



— 3 - — nmlHnstilosus (from Ingolf Exp. vSt. 51). 



— 4 - — magninsulosus. 



5 - 



6 - 



— ingolji (from Ingolf Exp. St. 27). 



