PLATE IV. 
PAGE 
Figs. 1-22. Chrotella macellata, . . 19-23 
Figure 1. Sponge ; nat. size. 
„ 2. Transverse section through the sponge ; nat. size. 
,, 3-15. Spicules — 
Fig. 3. Somal oxea of the spicular fibres; 
X 22. 
„ 4. Promonsene; x 22. 
„ 5. Prodiaene; x 22. 
„ 6. Trichodal protriaene; x 292. 
„ 7. Trichodal prodiaene; x 292. 
„ 8. Cladal end of the protrisene; 
X 180. 
,, 9. Anatrisene; x 17. 
Fig. 
„ 11 , 
5J 
10. Somal oxea of the spicular 
interspaces; x 22. 
12. Toxaspires of the cortex; 
X 292. 
13. Cladal end of an ana- 
trisene; X 180. 
14. Cladal end of a cortical 
pro trisene; x 180. 
15. Cladal end of a hispidat- 
ing protriaene; x 180. 
16. Longitudinal section through the wall of the cloaca ; x 34. 
17. Radial section through the sponge, showing the cortex and choanosome ; 
X 18. 
18. A part of the preceding more highly magnified ; x 49. 
19. Section through the lining membrane of the cloaca ; x 292. 
20. Section through a part of the choanosome, showing the aphodal flagel- 
lated chambers ; x 200. 
21. Section through an ovum ; x 292. 
22. Section through an ovum with pseudopodia-like extensions ; x 125. 
Figs. 23-31. Craniella simillima,^ . . .30 
„ 23. Sponge ; nat. size. 
„ 24-29. Spicules — 
Fig. 24. Somal oxea; x 73. 
„ 25. Anatrisene; x 73. 
■ „ 26. Protrisene; x 73. 
,, 27. Cortical oxea; x 73. 
Fig. 28. Cladal end 
X 180. 
„ 29. Cladal end 
X 180. 
of pro trisene ; 
of anatrisene ; 
30. Part of a series of cells frequently found on the sides of the megascleres ; 
X 180. 
31. Transverse section through a part of the cortex ; x 34. 
^ The specific name lowerhankii has been abandoned since the Plate was printed off. 
