XIII 



PHYLUM CHORDATA 



407 



tarso-metatarsus and four digits, the hallux being small and directed 

 backwards. 



In addition to the wing and tail-quills already referred to, there 

 are remains of contour feathers at the base of the neck and of wing- 



FIG. IOCS. Archaeopteryx lithographica. The skull, showing teeth and sclerotic 

 plates. (From Headley, after Dames.) 



coverts. Moreover the rectrices are continued forwards by a series 

 of large feathers which extend for some distance along the sides of 



FIG. 1069. Archaeopteryx lithographica. The left manus. e. carpal ; dl, first digit 

 2, second digit ; 3, third digit ; m, m. metacarpals ; r. radius ; u. ulna. (From Headley, 

 after Dames.) 



the body, and a row of similar but smaller feathers is attached along 

 both anterior and posterior faces of the tibio-tarsus. 



A second species of Archaeopteryx, which has been named 

 ArchcBOpt&ryx siemensi, has been found more recently in the same 

 locality. 



Sub-Class II. Neornithes. 



External Characters. In the general build of the body the 

 Neornithes differ from Archseopteryx chiefly in the shorter and 

 stouter trunk, and in the point of articulation of the hind-limbs 

 being thrown forward, so as to be almost directly below the centre 

 of gravity of the body : the animal is thus enabled without effort 

 to support itself on the legs alone. In a word Birds are essentially 

 bipedal, the only exception being the young of the Hoatzin 

 (Opisthocomus), which uses its wings in climbing. 



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