§ 16. 



THE SERTULARIA, OR VESICULAR CORALLINES. 



615 



zoophytes. The Sertularia consists of tubes united together, 

 and having lateral apertures for the protrusion of each 

 polype ; one elegant species, the Sertularia setacea, is very 



1 2 



Lign. 134. — Sertularia, or vesicular coralline. 



(Sertularia nigra, Dr. Johnston.) 



Fig. 1. Natural size. 2. A portion highly magnified. 



abundant on the shores at Brighton after storms, being 

 attached to fuci and other sea-weeds. This representation 

 of a branch magnified sixty times {Plate V. jig. 1) shows 

 the form of the polypes, which, when fully expanded, are of 

 great beauty. On one occasion, when I was present, Mr. 

 Lister was observing a living specimen, when a little 

 globular animalcule swam rapidly by one of the expanded 

 polypes ; the latter immediately contracted, seized the 

 globule, and brought it to the mouth or central opening by 

 its tentacula ; these gradually opened again, with the ex- 

 ception of one which remained folded, with its extremity on 

 the animalcule. The mouth instantly seemed filled with 

 cilia, that closed over the prey, which, after a few seconds, 

 was carried slowly down into the stomach ; here it was 

 imperfectly seen, and soon disappeared.* 



The Campanularice, so named from their bell-shaped 

 * Philos. Trans. 1834, p. 372. 



