PLATE X. 



Figure 



1. Phymanthus crucifer. Plan of tentacular arrangement. Owing to the closeness of the mesen- 



teries, only the pairs corresponding with the first five cycles of tentacles are represented. 

 The two outermost cycles (vi., vn.,) of tentacles appear as if communicating with the same 

 mesenterial chamber as some of the higher orders ; this is, of course, not the case in the 

 actual polyp. 



2. Phymanthus crucifer. Single tentacle of the first cycle. Slightly enlarged. 



3. Actinotryx Sancti-Thomce. A small polyp with the smooth peripheral region of the disc reflected. 



Natural size. 



4. Actinotryx Sancti-Thomce. A portion of the peripheral tentaculiferous part of the disc, x 3. 



5. Actinotryx Sancti-Thoma. Single discal or accessory tentacle, x 3. 



6. Actinotryx Sancti-Thomm. Plan of tentacular arrangement. The peripheral series form only a 



single cycle, but are of three orders, not always regularly alternating. The inner series 

 constitute a middle discal and a peristomial group. 



7. Ricordea florida. Polyp with two oral apertures. The tentacles are often a little more knobbed 



than is here indicated. Natural size. 



8. Homostichanthus anemone. Polyp, drawn from partly shrunk specimen preserved in formol. 



9. Actinoporus elegans. Living polyp. Slightly reduced. 



10. Corynactis myrcia. Retracted and extended polyps, still connected by a narrow coenosarc. 



Slightly enlarged. 



11. Parazoanthus tunicans. Portion of colony incrusting Plumularia. Natural size. 



12. Parazoanthus separatus. Portion of a sponge with commensal polyps; retracted condition. 



Natural size. 



13. Parazoanthus separatus. A single polyp, x 3. The three last figures were drawn by Miss 



Verley. 



14. Parazoanthus monostichus. Portion of sponge with numerous colonies. Natural size 



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