SKELETON. 

 FIG. 1G2. 



143 



mt 



P* 



Skeleton of a Bird. 



hd, head; c, cervical vertebrae; p, pelvis; sc, scapula; cl, clavicle; cd, corocoid 

 bone, formerly regarded as a second clavicle; st, sternum; h, bumerus; u, ulna; r, 

 radius; c, carpus; wic, metacarpus ; ph and th, phalanges, th being the thumb ; fe, 

 femur ; ft, fibula and tibia, more or less united; t, tibia, or where the fibula is no 

 longer seen, or only faintly indicated ; ts, tarsus ; mt, metatarsus more or less con- 

 solidated with the tarsus ; y, phalanges or toes. 



The upper jaw or mandible of Birds is so articulated with 

 the cranium that it can move independently of the lower 

 jaw a peculiarity which is not found in the Mammalia. 



The trunk, serving as a point of support for the ex- 

 tended locomotive members, has little flexibility, the ver- 

 tebrae of this portion being more or less firmly joined 

 together. The pelvis is much lengthened, furnishing 

 points of attachment for the muscles of the thighs ; and 

 the sternum is of great extent, to bear the extensive 

 muscles for moving the wings in flight. The ribs are 



