OBSERVATIONS ON THE DENTITION OF OHKYSOCHLORIS. 131 



distinct posterior cusp corresponding apparently to the 

 talonid^ a trace of a paraconid^ and possibly even a rudiment 

 of a metaconid. The first premolar has a well-developed 

 talonid, and a quite distinct though small trigonid, both the 

 paraconid and the metaconid being quite distinct. In all the 

 other premolars and molars except the rudimentary last 

 molar the teeth are formed of an elevated trigonid with a 

 small posterior talonid. 



In Chrysochloris asiatica the first upper milk premolar 

 is triangular but with no trace of protocone. The perma- 

 nent first premolar is smaller and with the anterior part 

 less developed. The other premolar teeth of both sets and 

 the true molars have a well-developed protocone. The lower 

 teeth resemble considerably those of C. villosa. The milk 

 canine has a large main cusp and a well-developed posterior 

 talonid cusp. The fii'st milk premolar has a large main cusp, 

 a well-developed talon, and distinct though rudimentary 

 paraconid and metaconid cusps. There is, however, no tri- 

 gonid formed. The other premolars are remarkable from 

 having lost the talon. The teeth of the permanent set are 

 smaller, and the first premolar has the paraconid and meta- 

 conid well formed, but not large enough to make a trigon. 

 There is on both the milk and permanent fii'st premolar a 

 distinct talon, and on the second premolar a faint rudiment, 

 but on all the other premolars and molars there is not a 

 vestige of a talon. 



In C. hottentota the main cusps of the molariform teeth 

 are exceptionally large, and in the unworn condition so much 

 higher than the others that the teeth appear to dilfer con- 

 siderably from those of some of the other species. The first 

 milk premolar is small and has no trace of a protocone. In 

 all the others, however, a protocone is present. In the 

 inferior teeth a posterior talonid cusp is present in all except 

 the first incisor. In the first premolar there is a large talon, a 

 feeble metaconid and a rudimentary paraconid. In the other 

 premolars and molars the talon is very large. The paraconid 

 aud metaconid are nmch shorter than the protocone. Approxi- 



