PLATE II. 
PAGE 
Figs. 1-4. Chrotella simplex, . . .17 
Figure 1. Eadial section through the cortex and adjacent choanosome ; x 90. 
„ 2. The same, less highly magnified ; x 22. 
,, 3, 4. Spicules — 
Fig. 3. Protrisene; x 125. | Fig. 4. Anatrisene; x 125. 
Figs. 5-20. Craniella simillima, . . . 30 
,, 5. Sponge ; nat. size. 
,, 6-10. Spicules — 
s Fig. 6. Oxea of the radial spicular fibres ; 
X 73. 
„ 7. Protrisene; x 73. 
„ 8. Cladal end of a protrisene; X 180, 
Fig. 
9, Cladal end of an anatrisene ; 
X 180. 
10. Cladal end of an anatrisene; 
X 180. 
11. A second example of the sponge ; nat. size. 
12. Transverse section through the cortex; x 15. 
13. Transverse section through , the cortex and adjacent choanosome; 
X 15. 
14-17. Spicules — 
Fig. 14. Protrisene; x 73. Fig. 16. Anatrisene; x 73. 
, „ 15. Cladal end of protrisene; x 180. „ 17. Cladal end of anatrisene; x 180. 
18. Section through one of the young sponges found within the body of 
the parent ; x 10. 
19. The same more highly magnified ; x 49. 
20. Parts of the rhabdomes of protrisenes from a young sponge, showing 
the scleroblasts ; x 430. 
