POLYZOA. 89 



will appear, at the very edge of tlie flame, a light of 

 most intense brilliancy, which is but another exhibi- 

 tion of the principle on which is produced the cele- 

 brated lime light, recently brought into notice for its 

 superior power of public illumination. The whole of 

 the substance of the cells, when viewed through a 

 microscope, is seen to contain a number of clear oval 

 grains, very much like the bubbles which we occa- 

 sionally see in bad glass ; they are, however, regular 

 in size and in arrangement. Their nature and use 

 are, I believe, entirely unknown. 



Through one of these oysters I made acquaintance 

 with another form of the same class, which has more 

 the appearance of a membranous seaweed than an 

 animal, the Bugle coralline (Salicornaria farcimi- 

 noides). It forms many slender flattened branches, 

 swelling regularly between the joints, and covered all 

 over their surface with ridges or raised lines, set 

 diamond-wise, and enclosing depressed cells of the 

 same form. The polypes which inhabit these cells are 

 probably similar in form to those of the Crisia ; but 

 I could npt detect a single individual on the specimen 

 that I examined, and I know nothing of them. 



Upon the whole the excursion of this day, though 

 accompanied with some unpleasant circumstances, 

 from the state of the weather and the sea, was one of 

 much gratification. The disagreeables were nothing, 

 or at least they lost their disagreeable character, as 

 soon as they had actually ceased ; while the pleasure- 

 able emotions produced upon the mind were repeated 



