OSTEOLOGY OF BIRDS 



191 



head of the scapula of the same side. Below, the sternal extremity 

 of the coracoid is moderately expanded, but offers nothing peculiar 

 as to form. The shaft is long, straight, and slightly compressed 

 from before, backward. For the " glenoid cavity," the coracoid 

 offers about two thirds of the articulatory surface; the scapular 

 furnishing the remainder. 



Either scapular presents in its 

 head or anterior end the usual 

 ornithic characters common to so 

 many of the Carinatae in general, 

 and to all true Gallinae in partic- 

 ular ; for we find its acromial pro- 

 cess, when the bones of the arch 

 are articulated in situ, extending 

 forward to meet the superior end 

 of the OS furcula, and its glenoidal 

 process completing, as usual, the 

 cavity for the head of the 

 humerus. Narrow, long, and 

 slightly curved, its blade in the 

 skeleton reaches back to the pelvis 

 or more, and is characterized by 

 having a smooth, rounded, outer 

 margin, and a sharp upturned in- 

 ner one, at least in the latter case, 

 for its posterior four fifths. Its 



distal apex is somewhat dilated. Possibly the scapula may be pneu- 

 matic ; the coracoid always is in this species, but the os furcula never 

 so. 



DISTANCES MEASURED IN CENTIMETERS 



r£^. zo- 



Fig. 19 Anterior view of the last 

 dorsal vertebrae and thoracic ribs {in 

 situ) of G. bankiva 



Fig. 20 Right lateral view of the 

 four coossified dorsal vertebrse from 

 the same bird; the vertebra shown in 

 figure 19 stands in the skeleton be- 

 tween this compound bone of the 

 spinal column and the pelvis 



Length of keel in sternum 



Greatest depth of keel in sternum 



Total length of sternum 



Distance between apexes of costal processes of sternum 



Distance between tips of outer pair of xiphoidal processes of sternum 



Length of OS furcula 



Length of coracoid 



Length of scapula 



Appendicular skeleton. The pectoral limb. As compared with 

 the rest of the skeleton, the limb bones of domestic species of 

 Gallus in the various modifications that have taken place in time 



