346 



SAUKOPSIDA (BIKDS). 



Class AVES. 



I. Sub-class ARCHiEORNITHES. 



Exlinct birds of the Jurassic period. — Terrestrial and aerial, let, 2nd 

 and 3rd metacarpals separate ; 2nd and 3rd fingers with three phalanges, 

 Conical teeth in upper jaw. Vertebrae amphiccelous. Caudal vertebne 

 21, no ploughshare bone. Twenty-four tail-feathers (rectrices) attached 

 in pairs to 12 caudal vertebrse. 



1. Arohseopterygiformes. — Including the Archceopteryx from the 

 Bavarian Oolite. 



Pro. 181.— TrPES OF Birds' Skulls. 



A, Skull of a gull (Larus), Scliizognathous type ; b, skull of raven, reduced (.SgiUi- 

 ognathous): Pmx, preniaxillary ; Mx.p, maxillo - palatine ; Vo, vomer; PI, palatine; 

 Mx, maxilla ; Ft, pterygoid ; Q, quadrate 



II. Sub-class Neoehithes. 



Metacarpals fused with each other. Second finger longest ; third re- 

 duced. Caudal vertebras apparently not more than 13 in number. 



