598 



ZOOLOGY 



SECT, xm 



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\\ 



COELENTERATA 



PORIFERA 



PROTOZOA 



FIG. 1250. Diagram illustrating the Mutual Relationships of the Phyla. 



