538 



ANATOMY OF VERTEBRATES. 



359 



process is smooth and flat, or slightly concave, in Tr. niger, and 

 developes a slight tubercle anterior to the stylo-hyal pit : in the 

 Tr. Gorilla the same process is more or less convex below, and 

 developes a ridge, answering to the vaginal process, on the outer 

 side of the carotid canal. The processes posterior and internal to 

 the glenoid articular surface are better developed, especially the 

 internal one in the Tr. Gorilla, than in the Tr. niger : the ridge 

 which extends from the ecto-pterygoid along the inner border of the 

 foramen ovale terminates in Tr. Gorilla by an angle or process 

 answering to that called ' styliform ' or ^ spinous ' in Man, but of 

 which there is no trace in the Tr. niger. 



The palate is narrower in proportion to its length in the Tr. 



Gorilla, but the premaxillary 

 portion is relatively longer in 

 Tr. niger. Two anterior palatine 

 foramina, one on each side the 

 almost confluent incisive fora- 

 mina, are more constant and 

 conspicuous in Tr. Gorilla : the 

 posterior palatine foramina are 

 nearer the posterior border of 

 the bony palate in Tr. niger. 

 The pterygoid fossa? are relatively 

 deeper and longer in Tr. niger. 

 The stronger zygomatic arches, 

 with the more developed sagittal 

 and lambdoidal crests, are adap- 

 tive developments concomitant 

 on the presence of larger ca- 

 nines and stronger mandible in 

 the Gorilla ; but the larger proportional molars and the smaller 

 proportional incisors, the prominence of the nasal bones at 

 their median line of coalescence, and the reappearance of the 

 premaxillarles upon the face above the nostril with their longer 

 enduring sutures, constitute a series of diff'erential characters of 

 more importance than such as are due to greater bulk or activity 

 of muscles, and are inexplicable by the operation of external in- 

 fluences. The basi-hyal, as in the Chimpanzee, is deeply excavated 

 behind : the cerato-hyals are obsolete : the thyro-hyals long and 

 nearly straight. Further characteristics of the skull of the highest 

 known Quadrumanous species will be shoAvn in comparison with 

 the cranial characters of the lowest races of Man. 



C. Bones of the Limhs. — In Quadrumanes, as in Quadrupeds, 



Base of skull, Gorilla, ciir. 



