122 NEW YORK STATE MUSEUM 



costal processes themselves. As in most all Accipitres, the principal 

 muscular line upon either side of the carina on the anterior surface 

 of the body of the sternum extends from the protuberance below 

 the outer termination of the coracoiclal gToove to a point about 

 -opposite the middle of the keel ; here it makes a rounded loop and 

 sweeps forward on the side of the keel, to the middle of its anterior 

 border, where it is met by the muscular line coming from the op- 

 posite side. 



The only pneumatic bone of the pectoral limb is the humerus 

 and it is strong and stout, showing to some extent the usual sig- 

 moidal curve. Its radial crest is conspicuous, very slightly flexed, 

 and is peculiar in being somewhat removed down the shaft from the 

 humeral head. A large, single, subelliptical air opening occupies the 

 pneumatic fossa. All the usual tubercles and processes are promi- 

 nent ,on this bone. 



Radius is long and comparatively slender, slightly arched, and for 

 its entire continuity nearly of uniform caliber. There is also a gentle 

 curvature along the shaft of the ulna, and it is faintly marked by 

 a row of the papillae for the quill butts of the secondary feathers 

 of the wing, and by a stronger second row running parallel to them. 

 Radiate and ulnare of the wrist present us with nothing that is very 

 noteworthy, and I have yet to find the os prominens in Pandion; 

 if it occurs it must be quite rudimentary, or possibly lost from the 

 skeletons at hand. 



As in the case of the bones of the forearm, carpomctacarpus and 

 manus are also unusually long including the bladelike phalanges. 



AVERAGE MEASUREMENTS OF THE BONES OF THE PECTORAL LIMB IN 



PANDION 

 Taken in centimeters and their fractions 



Humerus • i5-° 



Radius 18.4 



Ulna 19.0 



Carpometacarpus 9.0 



Proximal joint, index digit 4.4 



Distal joint, index digit 3.3 



Very minute pneumatic foramina are found in the popliteal fossa 

 and at their usual site at the proximal end of the bone in the femur 

 of the pelvic limb. I am inclined to believe that the pneumaticity 

 of the skeleton of the leg stops here. The femur is further char- 

 acterized by having a very extensive excavation for the ligamentum 

 teres ; the trochanter, usually broad in the anteroposterior direction, 



