456 AVES. 



are supposed to be the same as those present in living birds, and 

 possessed two, three, and four phalanges respectively. There 

 is a long tail composed of about twenty separate vertebrae which 

 carry the rectrices on each side (Fig. 248). 



The vertebrae appear to be amphicoelous, and the ribs are 

 devoid of uncinate processes. Abdominal ribs appear to have 

 been present. 



The beak is short and blunt, arid a circle of sclerotic plates 

 is present (Fig. 249). The sternum is not well preserved. The 

 scapula and coracoid appear to have been inclined to one an- 

 other, and the clavicles are united into a U-shaped bone. The 

 pelvic bones are separate at the acetabulum, and the preace- 

 tabular portion of the ilium is shorter than the postace tabular. 

 The hind limb is avine with four clawed digits, the phalangeal 



formula of which is 2. 3. 



, .S?^^*^. 4 . 5. The hand carries six, 



and the ulna ten remiges. 

 The rectrices are arranged 

 in pairs and are attached to 

 the caudal vertebrae (Fig. 

 248). 



Archacopieryx appears to 

 FIG. 249. skull and lower jaw of Arcfiae.op- have been of about the size 



teryy, mar.rura, Berlin specimen, rieht side, . 1 



nat. size (from S. Woodward, after Dames). OI a rOOK. 1 WO I airly com- 



plete specimens are known, 

 of which one is in the British Museum and the other at Berlin. 



Order 2. NEORNITHES. 



The Neornithes includes all other birds known. The meta- 

 carpals are fused with one another ; the thoracic ribs have 

 uncinate processes (except in the Palamedeidae) ; the tail is 

 much reduced in length and the last five or six of the caudal 

 vertebrae are usually united to form a pygostyle. They are 

 divided into three sub-orders, viz. Ratitae, Odontolcae, Carinatae. 



Sub-order 1. RATITAE. 



The ratite birds differ from all others in the combination of the 

 following peculiarities : (1) The sternum is devoid of a keel. (2) The 

 long axes of the adjacent parts of the scapula and coracoid are nearly 

 parallel or identical. (3) The posterior ends of the palatines and the an- 

 terior ends of the pterygoids are very imperfectly, or not at all, articu- 



