204 



THE BOTTOM OF THE SEA. 



are found. Most frequently the polypier is set with 

 polyps from its foot to its summit, although those at 



fig, 42. — Millepoia Alcicornis (one-fourth of the natural size). 



the base may no longer be living. Each of these 

 little animals is marked by the characteristics which 

 we have notice! more than once. The number of 



