EXPLANATION OF PLATE X. 



RIIIPIDIGORGIA FLABELLUM. LINN. 



Fig. I. Small zoanthodemc tvith polyps expanded., reduced one-half. 



Fig. 2. Portion of the same enlarged to show arrangement of polyps. 



Fig. 3. Expanded polyp, enlarged. 



Fig. 4. View of polvp from above slto-vin g folded tentacles. 



Fig. 5. Transverse section of branch: a, a, central pith of axis cylinder; b, 

 corneous part of axis cylinder; c, endodermal investment of axis cylin- 

 der; d, endodermal lining of calicle, continuous with e; e, e, endoder- 

 mal lining of water-vascular canals; f, f, spicules embedded in ccenen- 

 chyma; g, g, retractor muscles; h, gullet of pohp; i, i, expanded ten- 

 tacles; 3, mesentery; k, ovum. 



Fig. 6. f,ongitudinal section oj branch : a, corneous portion of axis cylinder; 

 b, central pith of axis cylinder; c, endodermal investment of axis; d, 

 e, endodermal lining of calicle; f, f, spicules embedded in coenen- 

 chyma; g, g, g, g, retractor muscles of polyps; h, stomach of polyp; 

 i, retracted tentacle; j, j, mesenteries; k, k, k, ova. 



Fig. 7. Transverse section of brancli 7iear tip sho'ving end oj axis cylinder : a, a, 

 axis cylinder; b, side of same; c, lining of calicle; d, d, d, mesenteries. 



Fig. 8. Spicule draivn to same scale as those on other Phites. The remaining 

 spicules are much more liiglily magnified. 



Figs. 9, 11, 12. Regular tuberculate fusform spicules. 



Figs. 10, 13. Scaphoid spicules. 



FiCi. 14. Dumb-bell-shaped spicule. 



Fk;. 15. Toung spicule. 



