172 DE. C. W. AKDEEWS OX LOWER MIOCENE [June 1914, 



cusps are V-shaped, and the anterior limb of the V is strongly 

 developed, that of the antero-external (protoconid) cusp extending 

 to the antero-internal angle of the tooth and entirely cutting off 

 the antero-internal cusp (metaconid) from the anterior border of 

 the tooth. Similarly, the anterior limb of the postero-external cusp 

 (hypoconid) extends quite to the inner border of the tooth, separating 

 the metaconid from the entoconid and blocking the inner end of 

 the transverse valley. The talon is a narrow loop, the outer wall 

 of which is much the highest ; posteriorly it terminates in a high 

 sharp cusp. A cingulum is present on the anterior end of the 

 tooth, and at the outer end of the posterior transverse valley. The 

 enamel is sculptured by a series of fine irregular ridges running 

 towards the tips of the cusps. The depth of the mandibular ramus 

 seems to have been greater than in Ancodon, in this respect approxi- 

 mating to JBracliyodus. 



In the height of its cusps the tooth above described approaches 

 those of some species of Ancodon, such as A. velaunus (Cuvier); 

 but it is distinguished from that genus by the strong development 

 of the anterior limb of the outer cusps and by their relations to the 

 inner cusps. In this respect it appears to resemble JMLerycops, at 

 least so far as it is possible to judge from Mr. Pilgrim's description — 

 the figures given by him are indistinct. There is also considerable 

 similarity with the corresponding teeth of WLerycopotamns and 

 Hemimeryx ; for the present, this species may be called Mery cops 

 africanus, sp. no v., but further material is necessary for its 

 complete determination. 



The dimensions (in centimetres) of this specimen are : — 



Length of specimen 6*7 



Depth of ramus beneath the middle of m 3 . . . 3*1 



Length of m. 3 3"1 



Widthofm 3 1-5 



Another tooth (PI. XXIX, figs. 4 a & 4 h) probably belonging to 

 a member of this group is a right lower canine tusk. This tooth, 

 as a whole, is strongly curved, forming an arc of a circle. The 

 crown, which is short, is shai^-pointed and triangular in section, 

 the outer somewhat convex face being the widest. The posterior side 

 is formed by a flat surface of wear, which on the inner side extends 

 down to the cement-covered root. The enamel is covered with 

 a series of fine irregular wrinkles, directed towards the summit 

 of the crown and most clearly marked on the inner face. The large 

 cement-covered root is roughly triangular in section, and is scored 

 along its length by a series of shallow grooves, one situated towards 

 the outer side of the inner face being much the most strongly 

 developed. This tooth, except for the shortness of its crown, is 

 remarkably similar to the canine of a small Hippopotamw. It 

 seems probable that, like the molar above described, it belonged 

 to an animal resembling Merycopotamus and perhaps ancestral 

 to Hippopotamus, which was almost certainly derived from an 

 Anthracotheroid type. 



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