564 



ON THE PREHISTORIC PIG IN BRITAIN. 



Width of nasals 



Maximum (interzygomatic) 



width 

 Maximum frontal (interector- 



bital) width 

 Minimum vertical . 

 Lachry mo -malar line 

 Height of lachrymal 



Fig. 8. Left lower third molar of Sus andamanemis, female, i| times the natural 

 size. 



This tooth shows the three divisions of the third molar of the true Suidae in 

 great simplicity. There are two bicuspidate lobes corresponding to the two principal 

 lobes of molar i and molar 2, and, like them, enclosing a single azygos lobe in the middle 

 line between them. This azygos lobe is developed from the second bicuspidate lobe. 

 There is no ridge developed in Sus andamanensis on the anterior part of the tooth, 

 i. e. on the face in contact with molar 2. Posteriorly to two bicuspidate lobes, which 

 already show signs of wear, are seen five smaller cusps, occupying in all a much 

 smaller space than the rest of the tooth. In the males of Sus cristatus these five 

 smaller cusps would, as in well-fed domestic pigs, occupy a very much larger space 

 relatively and absolutely than they do here, or even in Sus scrofa, var. ferus. In Sus 

 harhatus the third lower molars are as simple as they are in Sus andamanensis, and, 

 like this Sus, have the third molars of the upper jaw simpler still than the lower. 

 The five posterior cusps consist of one placed mesially in the interspace between the 

 primary cusps of the second pair, of three placed like the dots in the sign * . • , and of 

 a fifth, not constant, accessory cusp placed on the inner side. The four latter are 

 represented in the upper jaw of this pig by two, and in Sus harhatus by one 

 main cusp. 



