OSTEOLOGY OF BIRDS 



41 



TABLE SHOWING THE LENGTHS OF THE BONES OF THE PECTORAL LIMB 

 IN THE CATHARTIDAE, GIVEN IN CENTIMETERS; ALSO OF NEO- 

 PHRON PERCNOPTERUS AND GYPOGERANUS 



SPECIES 



HUMERUS 



RADIUS 



ULNA 



PINION 



Gymnogyps californianus 



27.8 



31.2 



32.8 



24-5 



Sarcorhamphus gryphus 



27 



30-3 



31.6 



23 5 



Gyparchus papa 



17 



20 . 4 



21.6 



151 



Cathartes a . septentrionalis 



Mo 



16.6 



17-5 



14-5 



Catharista urubu 



14 





16 



14 





MS 



16.7 



17. 1 



14 





18.5 



1 9 



19.8 



18.3 



In considering the relative position of points upon these segments 

 during the course of our remarks, we must consider the bony 

 framework of the wing as drawn up alongside the body in a state 

 of natural rest, as seen in the King vulture [Hayden's 12th An. 

 Rep't, pi. 15, fig. 105]. The head of the humerus is bent not only 

 downward, but anconad, the reverse being the case in the distal 

 extremity of the bone; these deflections, gentle as they are, and 

 extended to a certain share of the shaft, give to this segment, both 

 from superior and lateral aspects, the usual sigmoidal curvature. 



At the proximal extremity we find a well developed " greater 

 tuberosity " in the form of the ordinary smooth convex and curling 

 facet for the glenoidal cavity of the shoulder ; below this occurs 

 the tuberous and projecting " ulnar crest " or " lesser tuberosity " 

 overhanging a large subcircular fossa, at the base of which we note 

 the many pneumatic perforations, to allow the entrance of air at 

 this end of the bone. The radial crest occupies about one third 

 (Gyparchus) or more (Cathartes a. septentrionalis) 

 of its usual site on the superior aspect of the shaft, proximad, ex- 

 hibiting all of its most common points of interest. It is quite 

 vertical, turning outward but very slightly, and strongly marked 

 by elevated muscular lines; this crest terminates over the 

 greater tuberosity in a special broadened prominence, the continua- 

 tion of its platelike portion beyond. From a dilated humeral 

 head, we pass to a smooth and even shaft that presents but 

 little for our examination; it is elliptical on section throughout, 

 the long or major axis being vertical, while below and nearly 



