17 



Finally, a portion of a lower jaw with teeth and the shaft of a 

 humerus of a quadruraanous animal (Bryopithecus), equalling the size 

 of those bones in Man, have been discovered by M. Fontan, of Saint- 

 Gaudens, in a marly bed of Upper Miocene age, forming the base of 

 the plateau on which that town is built. The molar teeth present 

 the type of grinding surface of those of the Gibbons {Hylobates), 

 and, as in that genus, the second true molar is larger than the first, 

 not of equal size, as in the human subject and Chimpanzee. The 

 premolars have a greater antero-posterior extent, relatively, than in 

 the Chimpanzee, and in this respect agree more with those in the 

 Siamang. The first premolar has the outer cusp raised to double 

 the height of that of the second ; its inner lobe appears from 

 M. Lartet's figure to be less developed than in the Gorilla, certainly 

 less than in the Chimpanzee. The posterior talon of the second 

 premolar is more developed, and consequently the fore and aft extent 

 of the tooth is greater than in the Chimpanzee ; thereby the second 

 premolar of Dryojjithecus more resembles that in Hylobates, and 

 departs further from the human type. 



The canine, judging from the figures published by M. Lartet*, 

 seems to be less developed than in the male Chimpanzee, Gorilla, or 

 Orang ; in which character the fossil, if it belonged to a male, makes 

 a nearer approach to the human type : but it is one which many of 

 the inferior monkeys also exhibit, and is by no means to be trusted 

 as significant of true affinity, supposing even the sex of the fossil to 

 be known as being male. 



The shaft of the humerus, found with the jaw, is peculiarly 

 rounded, as it is in the Gibbons and Sloths, and offers none of those 

 angularities and ridges which make the same bone in the Chimpanzee 

 and Orang come so much nearer in shape to the humerus of the 

 human subject. The fore part of the jaw, as in the Siamang, is more 

 nearly vertical than in the Gorilla or Chimpanzee ; but whether the 

 back part of the jaw may not have departed in a greater degree from 

 the human type than the fore part approaches it, as is the case in 

 the Siamang, the state of the fossil does not allow of determining. 

 One significant character is, however, present, — the shape of the 

 fore part of the coronoid process. It is slightly convex forwards, 

 which causes the angle it forms with the alveolar border to be lessopen. 

 The same character is present in the Gibbons. The front margin 

 of the lower half of the coronoid process in Man is concave, as it is 

 likewise in the Gorilla and Chimpanzee. Prof. Owen was acquainted 

 with this interesting fossil, referred to a genus called Bryopithecus, 

 only by the figures published in the 43rd volume of the ' Comptes 

 Rendus de I'Academie des Sciences.' From these it appears that 

 the canine, two premolars, and first and second true molars, are in 

 place ; the socket of the third molar is empty, but widely open above ; 

 from which the author concludes that the third molar had also cut 

 the gum, the crown being completed, but not the fangs. If the last 

 molar had existed as a mere germ, it would more probably have been 

 preserved in the substance of the jaw. 



* ' Comptes Rendus de rAcademie des Sciences.' Paris, vol. xliii. 



No. 385. — Proceedings of the Zoological Society. 



