761 



5051. The skull of a large male Bornean Orang-utan, the Pongo of Baron Wurmb 

 (Pithecus Satyr us, var. Wurmbii)*. 



It shows the full dentition of maturity. The last molar is wanting in the upper jaw and 

 in the left side of the lower jaw of the Sumatran skeleton, but it is retained in both jaws in 

 the present skull. A slight trace of the maxillo-premaxillary suture is still discernible in the 

 fore part of the upper jaw. 



Presented by Sir William Blizard, F.R.S. 



005 -2. The radius and ulna of the same Orang-utan (Pithecus Satyrus, var. Wurmbit). 



The sigmoid cavity of the ulna is less equally divided than in Man, the outer division being 

 broader and its lower border more prominent : there is a deep elongated rough fossa beneath 

 this division on the fore part of the shaft, which does not exist in Man. The short but well- 

 marked ridge below the lesser sigmoid cavity of the Human ulna is very feebly represented 

 in the Orang. The canal of the medtdlary artery enters the fore part of the shaft and in- 

 clines proximad in both bones of the fore-arm, but enters lower down the middle of the shaft 

 of the radius in the Orang than in Man. The ulna is bent in the opposite direction to the 

 radius, whilst hi Man the shaft is straight, and that of the radius is less bent : in both bones 

 the interosseous margin is sharper and more produced in Man. 



There is a rough prominent ridge on the radial side of the distal expanded extremity of the 

 shaft of the radius in the Orang ; the fore part of that expanded end is excavated and the 

 styloid angle less produced than in Man. The styloid process of the ulna is more produced 

 than in Man, but the articular surface does not extend to it, being limited to the convex 

 border joining the radius, where it presents a reniform figure, longest in the direction from 

 before backwards. 



Presented by Sir William Blizard, F.R.S. 



5053. The right ulna of the same Orang-utan (Pithecus Satyrus, var. Wurmbif). 



Presented by Sir William Blizard, F.R.S. 



5054. The cranium, vertically and longitudinally bisected, of an adult male Bornean 

 Orang-utan (Pithecus Satyrus, of the variety called ' Mias Rambi'). 



The area of the nasal cavity equals more than one-third of that of the cranial cavity. 

 The most anterior part of this cavity is formed by the deep, narrow, and well-defined rhin- 

 encephalic fossa : the ' crista galli ' is rudimental. The division of the prosencephalic com- 

 partment, for the anterior and middle lobes of the cerebrum, is very slightly defined by the 

 orbitosphenoid. The tentorial ridge is not continued backwards beyond the petrosal, and 

 this is not impressed by a cerebellar pit. The basisphenoid has coalesced with the basiocci- 

 pital. The sphenoidal sinus is almost wholly formed by the presphenoid, and it is divided 

 by a longitudinal septum. The lower border of the basi-occipito-sphenoidal floor of the cra- 



* This appears to be the same with the Bornean Orang, called ' Mias Pappan ' by Rajah Brooke. 



5 E 



