MOLLUSCOIDA. 



1S7 



CHAPTER XIX. 



MOLLU.SCOIDA. 



Class I. Polyzoa. 



The members of this class are the lowest of all the Mollusca, and 

 the}' are generally known by the popular names of " Sea-mosses " 



Fi^,'. V:;\.—Fluslra fuKacm, one nf the Sp;i ui.its c Porticn of tlie colony, nutnirj 

 sizt- ; 6 A fragment niagniHed, to s}io\\ the < i ll^ iu which tlie seiiarate imlypidcs a;'e 

 contained. 



and " Sea-mats." They are invarialjly compound, forming associated 

 growths or colonies, often moie or less jjlant-like in form (tig. 131), 



