THE CHIMPANZEES AND ORANGS. 83 



structure occupies the usual place of this, below which, part of the interorbital sep- 

 tum formed by the hinder crista of the nasal bone and the frontal presents, as in the 

 Gorilla, a very compact dense structure. The small venous canal continued from the 

 foramen caecum traverses the base of this septum to terminate at the lower end of the 

 short nasal bone. The lamina perpendicularis sethmoidei presents a quadrate form 

 8 lines in diameter. 



The floor of the nasal cavity is shorter, thicker, and a larger proportion of it is con- 

 tributed by the premaxillary (22) in the Orang than in the Gorilla. The part of the pre- 

 maxillary divided by the section is absolutely longer, larger, and more nearly parallel with 

 the palato-nasal plate of the maxillary (21) than in the Gorilla. The nasal end of the 

 incisive canal is divided by the process extending from the premaxillary to the maxillary ; 

 but this is the only part of the premaxillary which has not coalesced with the maxillary ; 

 every other trace of the original suture has disappeared, even that on the palate. 



There is no production of the nasal below the crista sent backwards to form the dense 

 interorbital septum, and no production of the feebly marked superorbital boundary, 

 forwards and upwards, to form a crest, as in the Gorilla. The turbinal plates are less 

 developed than in the Gorilla ; the lower one is shorter than the one above ; and there 

 is not any plate answering to the small superior turbinal in the Gorilla and in Man. 



Both lambdoidal and sagittal cristae are much less developed than in the Gorilla. 



In comparing together the vertical sections of the Papuan and European skulls, the 

 relative proportion of the cranial and nasal chambers is seen to differ in a slight degree ; 

 the nasal chamber is nearly of the same size in both, — a little longer at its floor in the 

 Papuan ; but the cranial cavity is greater in the European, as is shown by the table 

 of the mean capacity of the cranium in the different races of Man and in the Chim- 

 panzee and Orang, p. 99. Although no part of the calvarium is raised into crests, yet 

 the whole calvarium is thicker in the Papuan, as it is in most African Negroes, than it 

 is in the European. But there is another character in which the Papuan more nearly 

 resembles the Orang, which I was not prepared to find, viz. the total absence of 

 frontal sinuses. The front wall of the cranium is thickened by a superorbital ridge, 

 and by protuberances that appear externally to be due to the usual sinuses ; but in 

 the vertical section the interval between the two tables was here seen to be occupied by 

 a fine cancellous structure. 



As this might possibly have been a mere individual variety, I had a section made of 

 another male Papuan skull from Tasmania, both vertically and horizontally, through 

 one of the protuberances, and found the same absence of any sinus. 



In a third cranium of an Australian, which showed external indications of the sinuses, 

 I made a horizontal section through the protuberances, about 3 lines above the brim of 

 the orbit, and the same close cancellous structure was exposed without any air-cavity. 

 If anatomists who may possess other crania of the Australian and Tasmanian Papuans 

 would repeat the investigation, a sufficient number of instances might be collected to 



VOL. IV. — PART III. O 



