SECTION VII. 



THE CLASS OF POLYZOA OR BRYOZOA OR MOSS-LIKE 



MOLLUSKS.* 



THE Bryozoa are small or minute mollusks growing in 

 clusters, and are exceedingly plant-like in their general 

 appearance. Some kinds belong to the sea, and are found 

 upon rocks, shells, and seaweeds. Others are confined to 

 fresh water ponds and streams, and are found attached to 

 sticks, and sunken logs, and to rocks and other bodies be- 

 neath the surface of the water. 



FIG. 665. 



Plumatella. 

 p, PUuuatella natural size; P, Plumatella magnified; i, termination of the intestine. 



One of the most remarkable tilings in the structure of 

 the marine bryozoa is that called " birds' heads." In some 



* Packard and others regard the Polyzoa as worms. 



