PLATE XIX. 



LETTERING ON THE FIGURES. 



b. can., 



c. isl., 

 ect. m., 



incr. lac. 



i 







basal canal. 



braohycnemic mesentery, 

 cell-islets, 

 ectoderm, 

 ectodermal muscle, 

 endoderm. 

 incrustations. 



lacunae produced by removal of 

 incrustations. 



mes., mesoglcea. 



mest. fit, . . . mesenterial filament. 



mes. sph. m., . . mesoglcea sphincter muscle. 



mr. m., .... macrocnemic mesentery. 



ass., oesophagus. 



ces. fft:, .... oesophageal groove. 



p. gr pigment granules. 



s.d., sulcar directive mesenteries. 



si. d., .... sulcular directive mesenteries. 



sp., spermaria. 



t., tentacles. 



Figure. 



1. Palythoa mammittosa (Ell. and Sol.), (p. 359). Vertical section through a portion of the upper 



free part of a polyp, from which most of the incrustations have been dissolved, x 50. 



2. Palytlioa mammittosa (Ell. and Sol.), (p. 359). Transverse section through the oesophageal region 



(diagrammatic), x 35. 



3. Palytlioa mammittosa (Ell. and Sol.), (p. 359). Transverse section through the oesophageal region 



of a younger polyp (diagrammatic), x 35. 



4. Palytlioa mammittosa (Ell. and Sol.), (p. 359). Transverse section through a partially extended 



polyp, passing through a portion of the grooved part of the disc, x 50. 



5. Palythoa caribcea, Duch. and Michl. (p. 365). Vertical section through a portion of the upper free 



part of a polyp, x 50. 



6. Palythoa caribcea, Duch. and Michl. (p. 365). Transverse section through a fertile mesentery, 



x 50. 



7. Palythoa caribcea, Duch. and Michl. (p. 365). Transverse section through the oesophageal region 



(diagrammatic), x 35. 



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