582 



ZOOLOGY 



SECT. XIII 



In accordance with these conclusions the mutual relationships 

 of the phyla may be expressed in a diagrammatic form as 

 follows : 



CHORDATA 



ARTHROPODA 

 MOLLUSCA 



MOLLUSCOIDA 



TROCHELMINTHES 



\ 



NEMATHELMINTHES 



PLATYHELMINTHES 



ECHINODERMATA 



COELENTERATA 



PORIFERA 



PROTOZOA 



1 



.2 



i 



, 



> 



i V 



4-; 

 1-^ 



t. c 



5 "5 

 i 5 



FIG. 1169. Diagram illustrating the Mutual Relationships of the Chordata. 



