194 TEETIAET VEETEBEATA OE THE EATtM. 



the point of the upper canine tusk, -while in Eloiherium, a more nearly related form, 

 there are sometimes two pairs of such processes, but they are directed downwards and 

 more or less club-shaped : in the latter genus also their function is unknown. 



On the side of the jaw there are several foramina. The most anterior of these is 

 immediately behind the alveolus of i. 1, the next two are beneath i. 3 and c, while the 

 last is behind the posterior border of the symphysis at the level oi pm. 2. 



The first incisors (i. 1) are broken off short, but it can be seen that they were greatly 

 enlarged and directed forwards. They were laterally compressed so as to give an 

 elongated oval outline in section; the outer side, at least, was enamel-covered. The 

 second incisor (i. 2) was a small rounded tooth, represented in this specimen by its 

 alveolus only. Behind this, at an interval of about 1'4 cm., is a small rounded root of 

 a tooth and immediately behind this a second rather larger. The nature of these is 

 doubtful : they look as if they might be roots of one tooth, but since from their position 

 this is not probable, they are here regarded as the roots of the third incisor (i. 3) and 

 the canine (c). The distance between the canine and first premolar is about 1 cm. This 

 enlargement of the anterior incisors and the very small size of the canine distinguish 

 Gerdohyus from the other members of the family, and at least justify its separation in a 

 distinct subfamily. The anterior premolar (j)m. 1) is a compressed tooth consisting of small 

 anterior and posterior tubercles and a high main cusp. In the next [pm. 2) there is a small 

 cingular ridge in front of the tooth and the main cusp is much larger, showing a tendency 

 towards division into an outer and an inner element. In wear it gives a triangular 

 surface, from the outer angle of which a ridge runs down the outer face of the tooth, 

 while from its front angle there is a small ridge connecting it with the anterior tubercle, 

 and similarly posteriorly a small ridge unites it with the posterior tubercle. The next 

 tooth {pm. 3) is similar, except that the posterior lobe is larger and shows a tendency to 

 give a V-shaped surface iu wear. In the last premolar {pm. 4) the replacement of the 

 main cusp by two elements is complete, the inner being small and rounded, the outer 

 larger and V-shaped in wear. From the anterior arm of the V a small ridge runs to the 

 small anterior tubercle, while from the posterior a low ridge runs back uniting it with 

 the anterior limb of the V-shaped posterior lobe. On the inner side of this last there is 

 a trace of a small inner tubercle corresponding to the postero-internal cusp of the molars. 



The characters of the molars are those of a primitive member of the Suidse, in which 

 the outer cusps are distinctly selenodont. Each molar consists of two pairs of cusps, the 

 outer V-shaped, the inner more rounded or pyramidal. In the first molar (ni. 1) the 

 outer cusp is considerably worn ; it consists of the main tubercle forming the apex of 

 the V, of which the arms form slight ridges terminating in small accessory tubercles, of 

 which the anterior is situated on the anterior border of the tooth, while the posterior is 

 connected by a slight ridge with the postero-internal angle of the inner cusp. The 

 postero-external cusp shows the selenodont character still more clearly: its small anterior 

 accessory tubercle partially fills the main transverse valley ; the posterior accessory 

 tubercle is on the hinder border of the tooth. The internal cusps are trihedral, and 

 in wear they also show some tendency to form a V-shaped surface, the opening of the 

 V of the antero-internal cusp looking outwards and backwards, that of the postero- 

 internal cusp outwards and forwards. There is a slightly developed cingulum on the 

 outer side of the tooth, most marked opposite the opening of the transverse valley and 



