Our Common Birds and How to Know Them 



A scale of sixteen steps is recommended in the CODE of the American Ornithologist's 

 Union as being "adequate to all practical requirements of even a refined system of classi- 

 fication." 



It is as follows : 



It would indeed seem to a layman that these sixteen grades afforded sufficient scope 

 for the classification of any ordinary bird. 



All birds, whether living or extinct, belong to the Class /tves. In this Class there are 

 five sub-classes, viz. : 



SAURUR/E. RATITVE. 



ODONTOTORMvU. 



ODONTOLC/S. 



