EXPLANATION OF PLATE IX. 



Figs, i— 15. — Racodiscula sceptrellifera. Carter, var. spiroglyphi, 

 nov. — 

 Figs. I — 7. — PhyllotriaeneSj X 75. 

 ,, 8 — II. — Desmas, X 75. 

 ,, 12, 13. — Fragments of the skeleton (lateral view), X 75. 



,, 14. — Fragment of the skeleton in contact with a 



shell (surface view), X 75. 



,, 15. — Microscleres (amphiasters), X 360. 



Figs. 16 — 18. — Racodiscula sceptrellifera, Carter, var. siliquariae, 

 nov. — 



Fig. 16. — Vertical section of a fragment of the skeleton 



in contact with a shell, X 75. (To show how 

 the cladi of the desmas become splayed out 

 horizontally in such positions.) 



,, 17. — Vertical section of a fragment of the dried sponge 



with enclosed shells from near the surface of 

 a mass, X 4. 



5, 18. — Half of (?) embryonic skeleton from efferent 



channel of the sponge, X 75. 



