456 



AVES. 



are supposed to he the same as those present in living hirds, and 

 possessed two, three, and four phalanges respectively. There 

 is a long tail composed of about twenty separate vertebrae wliich 

 carry the rectrices on eacli side (J'^ig. 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, and a circle of sclerotic plates 

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

 scapula and coracoid appear to l^ave 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 ])ortion of the ilium is shorter than the postacetabular. 

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



formula of which is 2. 3. 

 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). 



Archaropteryx appears to 

 Jiave been of about the size 

 of a rook. Two fairly com- 

 plete specimens are known, 

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



Fig. 249. — Skull .and lower jaw of Archacop- 

 teryx mar.nira, Berlin spcoimeii, right sif'p, 

 nat. size (from S. Woodward, after Dames). 



Order 2. NEORNITHES. 



The Neornithes includes ail other birds known. The meta- 

 carpals are f u.sed 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 visually united to form a pygostyle. They are 

 divided into three sub-orders, \ iz. Ratitae., Odontolcae, Cnrinatae. 



Sub-order 1. RATITAE. 



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

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

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

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

 terior ends of the pterygoids are verj'^ imperfectly, or not at all, articu- 



