EXPLANATtON 



Plate XIV. 



All the figures are diagrammatical. We see a (greyish) inner mass with 

 spicules and an outer epithelium illnstrated by a black line. 

 Fig. 1. Larva with cilae all over. 

 » 2. The cilae are partly lost. 

 » 3. ld.; the larva is less elongated. 

 » 4. Fixed larva. On the top a rest of ciliae. 

 » 5. All the ciliae lost. Subdermal cavaties appear. 

 » 6. Young sponge with subd. cav., canals and flagellated chambers 



(black spots). 

 Figs. 7 and 8. Portion of figs. 1 and 2, showing the place where the 

 flagellated cells are modified into cubic cells, and between 

 them gland-cells. 



