22 MANUAL 



The Old School divided the Animal Kingdom into 5 

 BRANCHES : 



I VERTEBRATES 



II ARTICULATES 



III MOLLUSCS 



IV RADIATES 

 V PROTOZOA 



The last 4 Branches, taken together, are called the IN- 

 VERTEBRATES, in distinction from the 1st or VERTE- 

 BRATES. Thus we speak of the Animal Kingdom, as a 

 whole, as being divided into 2 SUB-KINGDOMS : 



I VERTEBRATES 



II INVERTEBRATES 



The New School divides the Animal Kingdom into 8 

 Branches, and reverses the general order of their precedence, 

 thus : 



I PROTOZOA 



II PORIFERA 



III COELENTERATA 



IV ECHINODERMATA 



V VERMES 

 VI MOLLUSCA 



VII ARTHROPODA 

 VIII VERTEBRATA 



Here the first seven Branches constitute the Invertebrates, 

 as opposed to the eighth or the Vertebrates. 



Some writers do not make a separate Branch of the Porif- 

 era or Sponges, but connect them with the Protozoa and, after 

 the Mollusca, add the MOLLUSCOIDEA and the TUNI- 

 CATA as of the same relative value as the others. 



In either case we have to do only with the 



SUB-KINGDOM VERTEBRATA 



Both the Old School and the New School of writers unite 

 in dividing the Vertebrates into 5 distinct GROUPS : 



