130 K. BROOM. 



gested by Mivart in 1868, differing only in that Mivart 

 believed the internal ledge to be a fnsion of the protocone 

 and inetacone. A somewhat different view is that of Wood- 

 ward, who believed that the Chrysochloris upper molar 

 corresponded " only with the paracone triangle of the mole's 

 tooth." 



Before discussing the homologies of the cusps, it may be 

 well to look at the facts in some detail. In the best known 

 species, Chrysochloris asiatica (=C. capensis velC. 

 aurea), the molars are more degenerate than in any other 

 species except C. granti, and it is probable that it is this 

 species that was studied by Cope. When the teeth of tlie 

 larger and less degenerate types are examined, the nature of 

 the molars becomes more apparent. 



Chrj'sochloris villosa and C. trevelyani are the two 

 large species, and there is some reason to believe that most of 

 the small species are degenerate descendants of a larger 

 form, such as either of these two. Though many specimens 

 of C. trevelyani are available, it will be more convenient to 

 take C. villosa as the typical Chrysochloris, as in this 

 latter both the milk and permanent teeth are known. 



In figs, o and 4 are shown the upper and loAver milk-teeth 

 in an unworn condition. In figs. 1 and 2 the permanent set, 

 with the three true molars much worn. The most striking- 

 points of difference between the two sets are in the premolars. 

 There is little difference in size, but the upper dp^ is smaller 

 than 2^^, and shows no trace of the protocone, while p^ has 

 a small protocone. The two posterior premolars are both a 

 little shorter antero-posteriorly than the milk premolars. 



The lower milk teeth are interesting, in that a distinct 

 talonid is present on all the incisors, as well as on the canine 

 and three premolars. On the canine there is a small cusp 

 corresponding to the metaconid. In the first premolar the 

 metaconid is well developed, and there is a small paraconid 

 present. In the other premolars the trigonid is well formed. 



The permanent teeth of the lower jaw are in the main fairly 

 like those of the milk set. The canine is large and has a 



