GENERAL ZOOLOGY 



1. PORIFERA 



No true symmetry 

 Diploblastic (?) 

 No true tissues 



2. COELENTERATA and CTENOPHORA 

 Radial to bilateral 



Diploblastic to triploblastic 

 Tissues, no true organs 



3. PLATYHELMINTHES 

 Bilateral 

 Triploblastic 

 Non-segmented 

 Acoelomate 



Organs and organ systems 



MOLLUSCA 



Bilateral 



Triploblastic 



Non-segmented 



Eucoelomate 



Organ systems 



ANNELIDA 



Bilateral 



Triploblastic 



Segmented 



Eucoelomate 



Organ systems 



6. ECHINODERMATA 

 Secondarily radial 

 Triploblastic 

 Non-segmented 

 Eucoelomate 

 Organ systems 



CHORDATA 



Bilateral 



Triploblastic 



Segmented 



Eucoelomate 



Organ systems 



Fig. 7.6. Summary of general characteristics of major animal groups. 



like Vermes. Later, the Vermes were partitioned into several smaller phyla. 

 Again, Cuvier's Radiata were split into the phylum Echinodermata and the 

 phylum Coelenterata, and later the phylum Porifera was separated from the 

 coelenterates. Thus, more knowledge has made more phyla, although a limit 

 has apparently been reached in such groups as the Chordata, Arthropoda, 

 Mollusca, and Echinodermata, with their clearly defined characteristics (Fig. 



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