THE PIGEON 



407 



process, on its inner side. A slender splint, the jugal, joins it to a 

 third slip, the quadrato-jugal, which articulates with the outside of the 

 lower end of the quadrate. Thus there is formed a fine suborbital 

 bar. In the slender lower jaw, articular, angular, supra-angular, 

 dentary, and splenial ele- 

 ments can be made out. -P m - 

 There is a columella auris 

 and a slender, mainly bony, 

 forked hyoid apparatus. 



The shoulder girdle 

 contains narrow, sabre- 

 like scapulae, stout 

 coracoids which slope 

 down to join the 

 sternum, and slender 

 clavicles which unite 

 to form the " merry 

 thought." Where 

 scapula, coracoid, and 

 clavicle join, a small 

 opening, the foramen 

 triosseum, is left be- 

 tween them. The 

 sternum is a broad 

 plate, bearing below a -'-^•» ■"*• 

 conspicuous median 

 keel for the attach- 

 ment of the great wing 

 muscles, behind two 

 xiphoid processes, at 

 the sides facets for the 



ribs and in front SUr- ^'» Basitemporal ; Eu., hinder opening of passage 

 ' ., .. , for Eustachian tube ; Eu'., anterior opening of 



the same ;_/".w., foramen magnum; m., max- 

 illa ; mp., maxillopalatine process ; o.c, 

 occipital condyle ; pi., palatine ; pm„ pre- 

 maxllla;^., pterygoid; g., quadrate; g.j., 

 quadrato-jugal ; rs., rostrum ; IX., X., XII., 

 foramina for cranial nerves. 



Eu.: 



0. c. 

 Eu-.. 



XII 



f. m. 



Fig. 297. — The skull of a pigeon, seen 

 from below. 



faces for the articula- 

 tion of the coracoid 

 bones. In the wing 

 skeleton there is a 

 short, stout humerus, 

 a parallel radius and ulna, rather widely separated except at 

 their ends, where they touch, only two free carpal bones, 

 those of the second row having fused with the metacarpals, 

 of which there are three, fused together, and three digits. 

 The thumb has one joint, the first finger two, and the 



