PLATE XXXV. 
PAGE 
Figs. 1-11. Azoriea crassiuscula, . . . .324 
Figure 1. The sponge, seen from the poral surface ; nat. size. 
„ 2. A part of the sponge, seen from the oscular face ; nat. size. 
„ 3-11. Spicules — 
Fig. 3. Osea ; x 125. Fig. 11. A not quite adult desma, showing the 
,, 4. Part of a desma ; x 180. crepis ; x 180. 
„ 5-10. A series of desmas in different stages of 
growth, the youngest to the left; x 180. 
Figs. 12, 13. CoralUstes fhomad, .... 307 
1 2. The sponge seen from the poriferous face ; nat. size. 
13. The same seen from the oscular face ; nat. size. 
(For the spicules of this sponge, see PI. XV. figs. 40-46.) 
14-22. Spicules — 
Figs. 14-22. Azoriea marginata, 
Figs. 14, 15. Desmas ; x 63. 
„ 16. Part of a desma, showing syzygial 
processes. 
„ 17. Form frequently assumed by the 
desma near the surface of the sponge, 
the upper side of the drawing is that 
turned towards the surface in the 
sponge ; x 63. 
Fig. 18. Part of a desma, showing the syzygial 
ends ; x 225. 
„ 19. A young desma, consisting almost solely 
of the crepis, of which the axial rod 
is shown ; X 225. 
„ 20. Desma more advanced ; x 225. 
,, 21. Desma after treatment with caustic 
soda ; x 63. 
,, 22. Oxea ; x 180. 
323 
Fig. 23. Triptolemus dadosus, . 
23. Centrotrigene ; x 225. 
93 
Figs. 24,. 25. Isolated undetermined spicules, found associated with CoralUstes thomasi. 
24. This spicule, of which numerous examples were observed, presents a straight rhabdome 
measuring about 0'45 by 0'04 mm., traversed by an axial rod 0'24 mm. long, with 
numerous short, usually bifid cladi, given off all along its length ; these do not appear to 
be adapted for zygosis, and it is doubtful whether the spicule is to be assigned to the 
Monaxonida or the Lithistida ; it may be named provisionally Ortlioradiis ‘prohlematiea ; 
X 95. 
25. A microsclere probably of CoralUstes thomasi; x 300. 
Figs. 26-50. Sderitoderma flahelliformis, .... 316 
„ 26-28. The sponge ; nat. size. The first two figures represent the oscular, the third the poriferous 
face. 
,, 29-50. Spicules — 
Figs. 29-33. Various forms of the microstrongyle ; 
X 360. 
„ 34-41. The desma in various stages of growth, 
commencing with the youngest, 
X 95 ; fig. 35a is a more magnified 
representation of fig. 35 ; X 360. 
,, 42. The epirabd of a desma, showing the 
crepis ; x 200. 
Figs. 43-49. Various forms of desma ; x 95. 
Fig. 45 represents a form fre- 
quently assumed by desmas 
lying near the surface of the 
sponge. 
„ 50. Syzygial processes ; highly magni- 
fied. 
