38 Philippine Journal of Science isi» 



them, the lower end of the tube not having more than half the 

 caliber of the upper, where it makes a simple union with the 

 larynx. Distally, the bronchial branches are small, and but 

 half closed in, the mesial aspect of either being a thin, simple 

 membrane stretched across. There is a single pessalus present. 



THE SKELETON OF THE TRUNK 



The vertebral column. — All the skeletons of eagles that I have 

 examined possess fourteen vertebrae in the cervical region of 

 the spine, between the cranium and the first true dorsal vertebra. 

 Each of the last two cervicals — the thirteen and the fourteenth 

 — supports a free pair of ribs. On the thirteenth the pair is 

 rudimentary, to the extent that the body of the bone on either 

 side is lacking to some considerable degree, while the articulation 

 is perfect for the head and angle. With respect to the pair 

 of ribs on the fourteenth cervical vertebra, it has a length 

 of some 5 centimeters, terminating in a pointed, free extremity 

 well above the sternum. As this is the case with respect to 

 these last two vertebrae in Pithecophaga, Thrasaetos harpyja, 

 Aquila, and our white-headed eagle, it is probably what we will 

 find in the skeleton of any true aquiline species, irrespective 

 of the part of the world it inhabits. As a matter of fact, the 

 vertebral column of this monkey-eating eagle of the Philippines 

 is, character for character, almost the counterpart of that series 

 of bones in the harpy eagle, and departs but very little from 

 what we find in other species. 



In our present subject the atlas lacks both neural and haemal 

 spines, while the articular cup for the occipital condyle is 

 notched above. Laterally, there may be a notch or a foramen 

 for the passage of the vertebral artery upon either side. Its 

 neural arch is rather broad, and the facet for the centrum of 

 the axis is quadrilateral in outline, the width being twice that 

 of the vertical height. At the middle point below, it is pierced 

 longitudinally by a minute foramen ; a broad notch being found 

 at the same place in the atlas of the white-headed eagle. In 

 this species, too, similar notches allow, in life, the passage of 

 the vertebral arteries to the cranial cavity. Similar ones, though 

 larger, are to be seen in the axis of Pithecophaga, in which 

 vertebra are developed a stumpy haemal and a neural spine, as 

 well as a more or less insignificant odontoid process. 



The neural canal throughout the cervical series of vertebrae is 

 cylindrical in form and quite uniform in caliber. From the 

 third to the twelfth vertebra, inclusive, the lateral foramina for 



