Animals Before Man 



their own, are Polyzoa, or moss animals, and 

 Brachiopoda, or lamp-shells. The former are 

 of small size, and are associated 

 in colonies, which often bear a 

 strong superficial likeness to a 

 piece of seaweed, although on 

 closer examination this resolves 

 itself into an assemblage of little 

 animals each occupying a sort of 

 pocket or cell. 

 A poiyzoan. The brachiopods bear shells, 



Flustratruncaia. j i j 



and were long and not unnatu- 

 rally considered as belonging with bivalve mol- 

 lusks, which they closely resemble in outside 

 appearance. It may be said, however, that 

 while the two halves of such a shell as that 

 of a clam represent the two sides of the occu- 

 pant, in a brachiopod the valves cover the 

 upper and lower portions of the animal. The 

 inside of these shells often has curious loops or 

 spirals for the attachment, of the muscles that 

 move them, and in some species there is a sort 

 of stalk running through the point of the shell, 

 by which the animal is attached to the sea-bot- 



48 



