48 



OUTLINES OP NATURAL HISTORY. 



ormous number of little chambers or " cells," arranged 

 in a single layer. These chambers (fig. 19, h) have horny 



Jig. ig.—F lustra foliace a, one of the Sea-mats, a The plant-like colony, 

 natural .size ; h A fragment of the colony magnified, showing the little 

 chambers or cells, in which the separate animals fonning the colonv are 

 contained. 



walls, and are of an oval shape ; each having a little 

 transverse opening 01 mouth near its broadest end, and 

 having its upper margin provided with four conical 

 spines. Each cell contains a single animal, which leads 

 an _ existence independent of the others ; though the 

 entire assemblage, made up of all the little animals con- 

 tained in the innumerable cells, has also a life of its own, 

 as a whole. 



