PLATE XVIIL 
Disyringa dissimilis, . ... . 
igure 1. The cloacal tube of which fig. 18 is a transverse section; nat. size. 
„ 2. The cloacal tube of another specimen, showing the expanded hispidated termination ; nat. 
size. The position of this is inverted if the sponge be placed in the position of fig. 3. 
„ 3. Cloacal tube continuous with one-half of the sponge body ; nat. size. ■ 
4-13. Spicules — 
Fig. 4. Orthomonaene ; x 32. 
,, 5. Orthotriaene, with cladus much over- 
developed; X 32. 
,, 6. Dichomonaene ; x 32. 
,, 7. Cladome of a triaene seen en face; one 
cladus is simple and weU developed, one 
reduced to a tubercle, and the third is a 
dichocladus with the deuterocladi re- 
duced to tubercles ; x 32. 
Fig. 8. Somal orthodiaene ; x 32. 
,, 9. Somal orthomonaene ; x 32. 
,, 10. Somal oxea; x 32. 
,, 11. Sanidasters; x 540. 
,, 12. Oxyaster ; x 540. 
,, 13. Orthodragma, with its scleroblast ; 
X 540. 
14. Transverse section through a part of the sponge, showing the cortex and a part of the 
choanosome; x 22. 
15. Transverse section through a cloacal tube with four canals ; x 10. 
16. 16a. Sections through part of the choanosome, showing the flagellated chambers ; x 225. 
1 7. Part of a longitudinal section through the cloacal tube of which fig. 15 is a transverse 
section; x 11. 
18. Transverse section through a cloacal tube, with 16 — 1 canals; x 5‘5. I. primary canals ; 
II. secondary ; and III. tertiary canals. 
19. A part of the preceding section, more highly magnified ; x 16. 
20. Sectipn through the outer wall of the cloacal tube, with some of the adjacent strands 
of collenchyma, containing large pale vesicular cells ; x 225. 
21. One of the vesicular cells of fig. 20 ; x 36 
22. A flagellated chamber, showing the fenestrated membrane; x 540. 
23. Part of the outer wall of the cloacal tube from the outside, showing the longitudinal and 
transverse strands of fusiform cells which divide it into pore areas; x 360. 
24. Tissue adjacent to one of the spicules of the cloacal tube, showing fibridated fusiform cells 
extending over the spicule, and between them deeply coloured granular collencytes ; 
X 200. 
25. A fusiform cell from a spicule tract ; x 360. 
26. The fusiform middle part of a myocyte ; x 360. 
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