214 LEIDY'S OSTEOLOGY OF THE HEAD OF HIPPOPOTAMUS. 



received, the bones were still held together by their natural attachments, and in this 



condition the following measurements were taken : 



Length from nose to end of tail, in a straight line . . . . 5 ft. 8 in. 

 Length of spine, following curvatures from the inion . . . . 4 " 8 " 

 From ankle to hip joint, in a straight line . . . . . 1 " 7 " 



From scapula to wrist . . . . . . . . . 2 " " 



The sutures of the head are all open except the occipito-parietal. 



The deciduous molars have not been shed, nor has the last true molar commenced 

 to protrude. 



The epiphyses of the vertebral bodies are separable, also the head of the os 

 humeri, extremity of the olecranon, distal extremity of the ulna and radius, trochan- 

 ters and condyles of the os femoris, and head of the tibia. In all other positions the 

 skeleton is perfectly ossified. 



3. The skull of an old individual, probably a female. From St. Paul's river, 

 Africa. Belonging to Dr. Morton's collection. 



The canines, incisors and anterior two premolars are lost from the specimen, but 

 their alveoli remain. The first permanent true molar has its enameled triturating 

 surface obliterated, and all the cranial sutures have disappeared. 



4. The head of a nearly adult individual, probably male. From the same locality 

 and belonging to the same collection as the preceding. 



The deciduous molars had just been shed, and the last true molar had not fully 

 protruded, as is the case also with the fourth upper premolar. The sutures have been 

 nearly obliterated, excepting those surrounding the ossa nasi. 



5. An inferior canine tooth. From St. Paul's river, Africa. Presented by Dr. 

 Goheen. 



The head of Choeropsis Liberiensis is about one-fourth the bulk of that of Hippopo- 

 tamus Capensis. In the former, its longitudinal outline above is convex, rising from 

 the occipital region along the sagittal crest to the forehead, and then gradually 

 sloping downwards to the end of the nose. In Hippopotamus the same outline 

 descends or is level from the occipital summit to the forehead, then gently rises upon 

 the bones of the nose, and very gradually slopes downwards to the end of the latter. 



In viewing the outline of the skull from above, it is observable on each side in 

 Choeropsis, that an oblique line nearly straight converges from the bend forward of the 

 zygomatic process, to the vicinity of the infra-orbitar foramen, and then immediately 

 diverges in a straight line upon the canine alveoli. In Hippopotamus, the corre- 

 sponding line posteriorly is more irregular or undulant in its course, and its anterior 

 portion longer relatively, and curvilinear. 



In both animals the relative breadth between the zygomae is the same, but ante- 



