142 MAMMALIAN DENTITION 



line. The small lower incisors are vertical. The uppers are 

 also vertical, the small size of the lateral members resulting in 

 the stout but non-projecting upper canines being placed rela- 

 tively close together. The loAver canines again are also stout 

 teeth. The upper premolars are bicuspid and set well within 

 the molar line, the second being distinctly the smaller. In the 

 lower premolars this relation is reversed but though the 

 second is the larger of the two it is nevertheless much smaller 

 than the first molar. As in the case of the upper teeth the 

 labial face of the lower molars does not project so far laterally 

 as the labial aspect of the molars. In both jaws the first molar 

 is the largest and most reminiscent of ancestral form and the 

 size diminishes through the second to the third. The upper 

 molars are rhomboidal and in each the transverse diameter of 

 the crown measured over the protocone and the paracone con- 

 siderably exceeds the antero-posterior dimensions. The first 

 shows a well-developed hypocone, the second a hypocone ob- 

 viously reduced and the third practically no hypocone at all; 

 in this last tooth the metacone also is considerably reduced. 

 In the lower molar series as in the upper the first tooth is the 

 most stable, the more progressive second and third are smaller 

 than the first, Each molar displays the hypoconulid (except 

 the right third) a cusp which tends to be absent in modern 

 Man especially on the second molar. All the lower molars are 

 remarkable for their rounded contour. The antero-posterior 

 axis of the first is set at an angle with that of the second in 

 characteristically human fashion. As in H. heidelbergensis the 

 teeth are considerably worn down. 



Turning now to the Neandertal type (Homo mousteriensis 

 hauseri, Fig. 51) we find the teeth in general somewhat simi- 

 lar to, though larger than those of II. aurignacensis but also 

 distinctly human. The mandible has a more rounded angle 

 than that of H. aurignacensis and a body of less vertical 

 depth especially in the incisor area. The mental region is 

 very differently shaped, there being no chin. A much greater 

 deposit of bone encroaches upon the tongue area than in H. 



