NO. 12 JAW OF PILTDOWN MAN MILLER 21 



Remarks. — Within the limits of the generic characters recent 

 chimpanzees, like other great apes, show many variations the nature 

 of which is imperfectly understood. Numerous species have been 

 described 1 but their cranial peculiarities, if such exist, are not yet 

 known. Among the skulls in the National Museum series I have 

 been unable to find satisfactory characters by which to distinguish 

 local forms. 



Comparing the Piltdown mandible with those from Kameroon 

 and French Congo I have found no constant features other than those 

 already mentioned. That part of mandible in front of m 1 is, for 

 instance, shorter than in the two African jaws figured on plate I ; 

 but No. 174710 (pi. 5, fig. 2) from French Congo has this region fully 

 as short and nearly as deep as the type. In Pan veins the thickened 

 area which extends downward on outer side of mandible in contin- 

 uation of the base of the coronoid process is more prominent than in 

 most African specimens. It contributes to the robustness of the jaw 

 in that region, and stands out noticeably beyond the level of the lower 

 edge when the mandible is viewed at a certain angle from above. In 

 African specimens this thickening is usually not sufficient to project 

 noticeably beyond the level of the angular margin, but in No. 176235 

 from southern Kameroon it does so almost as much as in Pan veins. 

 The angle of the jaw is more evenly rounded off in Pan veins than in 

 mqst African chimpanzees that I have seen. These usually show a 

 slight concavity below the angular region and another, often the 

 more pronounced of the two, above it. In No. 174710 (pi. 5, fig. 2) 

 from French Congo a very slight wearing away of the edge of the 

 bone such as appears to have taken place in the Piltdown jaw would 

 exactly produce the outline of the type. The teeth appear to be more 

 diagnostic than the jaw, as I have been unable to find any African 

 specimen in which they equal those of Pan veins in size. 



1 See Elliot, Rev. Primates, vol. 3, pp. 229-254 June, 1913, and Matschie, 

 Sitzungsber. Gesellsch. naturforsch. Freunde, Berlin, 1914, pp. 327-335, J u b 7 > 

 1914. 



