Plate I. 



Page 



Fig. i. Tedania suctoria O. Schmidt The large papilla is an oscular papilla, '/i I 



2. Tedania suctoria O. Schmidt. A branched specimen, partly incrusting a Ptilota. I / I 



3. Tedania suctoria O. Schmidt. Incrusting specimen on an Allopora. 1 / I 



4. Tedania suctoria O. Schmidt Pore-papilla in longitudinal Section, x about 30 



5. Tedania suctoria O. Schmidt. Oscular papilla in longitudinal section, viewed from inwards, 



x about 30 -. 



6. Histoderma appendiculatum Cart. Most fistulse broken off, one ending in the way mentioned 



in the text '/ t 7 



7. Histoderma appendiculatum Cart. Small specimen. J /i 



8. Histoderma appendiciilatum Cart Section showing the small incurrent canals radiating 



inwards from the space below the dermal layer, and some larger, excurrent canals. J /i 



9. Histoderma appendiculatum Cart The inner body, removed from the dermal layer, 



showing the openings of the incurrent canals, seen translucently as dark points. 2 / t . 



10. Histoderma appendiculatum Cart. A piece of the surface of the inner body at the base 



of a fistula, showing the fibres at the surface, running together towards the base of 

 the fistula, x 32 



ii. Histoderma appendiculattim Cart End of a pore-fistula, x about 20 



12. Histoderma physa O.Schmidt, groving on a stone; the specimen has two oscular tubes. I / s 11 



13. Histoderma physa O. Schmidt Oscular tube with pore-sieve on the side, x about 3 .... 



