j,. NEW YORK STATE MUSEUM 



barbatus) [Collec. U. S. Nat. Mus. no. 17834]- A number of 

 figures of the bones of the skeleton of these two species are to 

 be found in my plates. . 



Almost the entire skeleton of Helotarsus is pneumatic, and al- 

 though osteologically the bird is a true eagle, it differs, among other 

 things from such a form as Haliaetus le u coc epha lu s , 

 iu having large foramina, one upon either side, in. its sternum , m 

 having in the skull, the external narial apertures largely filled in 

 with bone; while in the pelvis, the anterior parts of the ilia are not 

 nearly so much spread out laterally. The bones of the shoulder 

 girdle possess the same general morphology in the two species, 

 Helotarsus differing principally in its having the conspicuous pneu- 

 matic openings; especially in the large foramen near the head of 

 either scapula. The long bones of the limbs are much alike in 

 Helotarsus and the White-headed eagle. a 



G y p a e t u s b a r b a t u s possesses a skeleton that offers many 

 points of interest to study. Many of its principal bones are illus- 

 trated hi my plates, especially the skull, sternum, and pelvis Al- 

 though pneumatic, many of the bones of the skeleton of the Lam- 

 nrergeyer are solid and heavy, ideologically, the bird is o very 

 powerful frame. The furcula is of the wide U-pattern, and its free 

 ends superiorly do not articulate with the scapula upon either side ; 

 an interval of five millimeters existing between them when the 

 bones of the arch are naturally articulated. The body of the s er- 

 num is short, and the keel to this bone quite shallow. In the pelvis 

 ■ the postpubic styles are entire, and, upon superior aspect, it will be 

 seen that very complete fusion exists among the ossa innominata 



and the pelvic sacrum. wm-IH 



Considered osteologically, the Lammergeyer is an Old World 

 vulture built essentially upon the eagle model, as Gyps f u 1 v s 

 is an eagle-vulture, built essentially upon the Cathartme type. A 

 comparison of the skulls shown in figures a and 3 of P^ ^' jf 

 figure 4 of plate 3, and figure 7 of plate S> with figure 12 of plate 7 

 S demonstrate in a general way what is intended to be conveyed 

 upon this point. G y p o g e r a n u s s e r p e n t a r 1 u s [pi. 1, 

 fi. 1] also stands in here, for it possesses both eagle and vulture 

 in thi characters of its skeleton; the .sternum being short, with 

 a shallow keel, and (usually) no xiphoidal foramina The post 

 Julie styles are entire, as is the case in vulturine ^fj^ 

 while as we are well aware, the most extraordinary departure the 

 lecretarylirds make from their relatives in the suborder to which 



