198 ZOOPHYTES. 



Plate XXXVIII. Sertiilaria argentea. 



3. Section of the branch of another specimen, showing the figure and 



arrangement of the cells. 



4. Hydra. 



5. Vesicle. 



6. Compound prolific vesicles with spherules. 



7. Planulse from the vesicle, a ; one magnified, h. 



8. Nascent Sertularia from a planula. 



9. Nascent Sertularia farther advanced. 



10. Nascent Sertularia, still farther advanced, having two cells and a 



hydra. 



11. The upper portion, here inverted, of a bisected stalk, which consisted 



of A 11, and B 12, united at the point of division. Reproduction, 

 c, b, as on June 13, from what had been the lower extremity, c, 

 fig. 11, on bisection May 26. 



12. The lower half of the bisected stalk, preserved in the natural erect 



position, producing c, b, by upward vegetation, as appearing 

 June 13. 



13. The same reproduction, c, b, fig. 12, with additional regeneration, 



c^ a^ — c, d, consisting in whole of three branches, on December IS. 

 The portion c, B, as seen fig. 12, is here abbreviated. 



14. The same section, fig. 13, having generated reproductions from the 



lower extremity, B, a new stem, a, b, had arose from one of these, 

 a lateral filament, which stem had ten cells on November 9. 



15. This new stem, a, b, with its ten cells, as appearing November 9, en- 



larged. 



16. The same, with its accessions, on November 22. 



17. The same, with farther accessions, as appearing December 13. 



All the figures of this Plate, except figs. 1, 11, 12, 13, 14, are en- 

 larged. 



§ 12. Sertularia antennina. — Plates XXXIX., XL. — How nume- 

 rous soever the multitude of living hydrae which shall be ultimately borne 

 by any of the Sertularise, all those whose tenants are provided with muri- 

 cate tentacula, originate from the planula so often referred to, in as far as 

 I have been able to trace them. Whether a perfect specimen shall bear 



