CAMPANULARIA. 223 



Thus, hydrae are generated from descending as well as from ascend- 

 ing parts of the Sertularia dumosa. I know not whether this may be 

 found a feature more peculiar to zoophytes with a compound stem. 



Plate XXVI. Fig. 22. Sertularia (Campanularia) dvmosa. 



23. Portion shewing the form of the cells : hydrse in decay. 

 2-1. Portion with the hydra displayed. This is the extre- 

 mity of a branch. Vegetating shoots, a. 

 25. Portion of another specimen, with cells and hydrse. 

 All these figures, except 22, are enlarged. 



§ 4. Sertularia (Campanularia) syringa — Creeping Bell Coralline. 

 — Plate XII. Figs. 9, 10. — I find some difficulty in identifying this pro- 

 duct with what learned authors distinguish by the same name. The ac- 

 companying figures may be a guide to the truth. 



In certain respects the syrincja falls within the characters assigned to 

 the genus Campamdaria, but not in others. 



It always occurs, in as far as I have seen, as a parasite, ascending 

 other zoophytes like a slender thread, bearing cells with hydrae. 



To the naked eye, the cells are like so many spines of horn colour, 

 but seldom contain living animals, which perhaps indicates their delicacy. 

 They are of a long and somewhat campanulate shape, with an even lip, 

 rising on short pedicles, from the stem or thread, with about four whirls. 

 The pedicles originate at a considerable distance from each other. The 

 hydra protrudes a long, slender, transparent body, crowned by about 

 16 muricate tentacula. That number has been ascertained as the com- 

 plement of several. I have not observed any of the hydrse with only 

 eight tentacula, which is, in fact, a very rare characteristic of any of the 

 marine bydraoid zoophytes. I do not deny its existence, however. Such 

 a number of muricate tentacula may be rather incidental than general. 



The whirls are occasionally very distinct ; but I have never been able 

 to ascertain that they are in a twisted form or arrangement. 



As the bell or cell does not fall on losing the hydra, its relation to the 

 animal seems different from that of some species of the Campanularia. 



