524 DESCRIPTION OF THE MUSEUM. 



animal ; the second, those that are disunited, and 

 which have no internal communication, although 

 they are often grouped together or lie very 

 close to each other. We observe among those 

 of the first section, ist, the pjrosoma atlantica, 

 discovered by Peron : it is an hollow cylinder, 

 closed at one end, open at the other, and covered 

 with tubercles, which are so many little animals. 

 It is so highly phosphorescent, that where it 

 abounds the sea appears covered with burning 

 coals, from whence its name, which signifies 

 body of fire. When its phosphorescence ceases, 

 it assumes various colours. 2d. The sinoicum 

 aurantiucum, brought from New Holland by Pe- 

 ron, and of which M. Lamouroux has formed the 

 genus telesto: a dried specimen may be seen in 

 one of the cases of madrepores near the tubula- 

 riae. 3d. A new genus brought by M. Delalande 

 from the seas near the Cape. Examples of the 

 second section will be found in the salpce, which 

 float like long ribbons and form garlands on the 

 surface of the sea in warm climates ; and in se- 

 veral ascidice, such as the a. mammillaris , which 

 is found on our own shores, and the a. conchilega 

 from the Cape. 



The class of the radiaria, to which we shall 

 next proceed, has been so named on account of 

 the body's being formed in the manner of rays. 



