AVES. 



407 



432. Classification of Aves. 



Subclass I. Sannirce (Tailed, Reptilian Birds). These are 

 extinct birds related to the extinct reptiles the dinosaurs in 

 having a vertebrated tail, and jaws bearing teeth. Each ver- 

 tebra of the tail possessed a pair of feathers, the tail thus hav- 

 ing a row of rectrices on either side. 



FIG. 208. 



FIG. 208. Ostrich (Strutliio). From Wood's Natural History. 



Questions on the figure. Which of the types of feathers of ordi- 

 nary birds become the plumes in the ostrich? What is the real size of 

 the ostrich? 



Archaeopteryx, of which two specimens have been found in 

 the lithographic quarries of Bavaria, represents the group and 

 was about the size of a crow (Fig. 206'). 



Subclass II. Neornithes (Modern Birds}. This group is 

 characterized bv the reduction and fusion of the tail vertebrae 



