144 THE» WORLD OF THE SEA. 
either divided into compartments, or are of a more simple con- 
struction. There is a well-known and interesting member of this 
HYDROMEDUSA, 
(Vogtza.) 
class of creatures, called in the language of science, Physalia, but 
by sailors it is designated by the more expressive names of she sea 
bladder, the little galley, or the Portuguese man-of-war. In the 
