PLATE XVIII. a. 



LETTERING ON THE FIGURES. 



b. can., .... basal canal. 



c. isl., .... cell-islets. 



ect ectoderm. 



ect.fd., . . . ectodermal folds. 



d. mes. sph. »»., . double mesoglceal sphincter muscle. 

 end., .... endoderm. 



end. m., . . . endodermal muscle. 



incr., .... incrustations. 



mes mesoglcea. 



mest., .... mesentery. 



mest.fil., . . . mesenterial filament. 



mes. sph. m., . . mesoglceal sphincter muscle. 



mes. c. mesoglceal cells. 



mes. lac, . . . mesoglceal lacunae. 



p. b. m., . . . parieto-basilar muscle. 



netn., nematocysts. 



ov ovum. 



as., oesophagus. 



p. ffi\, .... pigment granules. 



sub-eu., .... sub-cuticla. 



sp., spermarium. 



zooz., .... zooxanthellae. 



Figure. 



1. Zoanthus Solanderi, Les. (p. 335). Vertical section through a portion of the column- wall, x 50. 



2. Zoanthus flos-marinus, Duch. and Michl. (p. 339). Vertical section through a portion of the 



column-wall, x 50. 



3. Zoanthus pulchellus (Duch. and Michl.), (p. 341). Vertical section through a portion of the 



column-wall, x 200. 



4. Zoanthus pulchellus (Duch. and Michl.), (p. 341). Transverse section through a portion of the 



column-wall and a fertile mesentery, x 50. 



5. Isaurus Duchassaingi (Andres), (p. 346). Vertical section through the upper portion of the 



column-wall, x 25. 



6. Isaurus Duohassaingi (Andres), (p. 346). Section through a portion of the mesoglcea of the 



body-wall, showing cells with peripheral granular protoplasm, x 250. 



7. Gemmaria variabilis, n. sp. (p. 350). Vertical section through a portion of the column-wall, 



x 25. 



8. Gemmaria variabilis, n. sp. (p. 350), Transverse section through a portion of the column-wall 



and a fertile mesentery, x 200. 



9. Gemmaria variabilis, n. sp. (p. 350). Transverse section through a portion of the column-wall 



and a perfect mesentery in the region of the oesophagus, x 50. 



10. Gemmaria fusca, n. sp. (p. 54). Vertical section through a portion of the column-wall, x 40. 



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