Figure 9 



This drawing shows several marine animals growing on a wharf piling, and 

 the free-swimming Squid, a highly developed Mollusc, in the water at the 

 lower left. Attached to the piling in the center are several black-shelled 

 Molluscs (Mytilus), above which is a Tunicate, Molgula. The stalked Tuni- 

 cate (Ciona) is shown below. Amaroucium, a colonial Chordate, is attached 

 to the right of Mytilus. The Coelenterate, Obelia, projects to the left above 

 Mytilus ; and Pennaria, at the lower right-hand corner. Adapted from a 

 group at the American Museum of Natural History. 



Ill 



