MiLK-DENTiTlON OF THE RATEL. 223 



In the permanent upper dentition of Ratels the carnassial 

 (p. 4), ill common with that of nearly all otlier living Mustelines, 

 has the inner tubercle placed close up to the front edge of the 

 tooth, while the molar (m.l) is characterised by the antero- 

 posterior diameter of the inner half of the crown being greatly in 

 excess of that of the outer half. In the milk-dentition, on the 

 other hand, the carnassial (which in most Carnivora is a replica 

 of the permanent one) has its inner tubercle placed near the 

 middle of the blade ; while, as I gather from another specimen, 

 the inner half of the molar is much narrower than the outer, 

 this tooth having, in fact, what may be called the typical 

 carnivorous triangular form. 



Now in both tlie foregoing respects the aforesaid milk-teeth 

 correspond in general characters with their permanent repre- 

 sentatives in Galictis ; the upper carnassial of that genus being 

 peculiar among existing Mustelines on account of having the 

 inner tubercle placed near the middle of the blade. There are, 

 of course, differences in regard to the details of these teeth, and 

 also in respect to the orientation of the molar, when the milk- 

 series of Mellivora is compared with the permanent set of 

 Galictis ; but the resemblance is such as to leave Httle doubt as 

 to genetic affinity between the animals to which they respectively 

 belong. And it would thus seem that the milk-teeth of the 

 Ratel and the permanent ones of the Tayra represent a common 

 primitive type, which has been superseded by a more advanced 

 modification in the permanent teeth of the Ratel. 



Text-fig. 32. 



Outer side of left upper milk-dentition of Mellivora, 

 showing the bifid or bicuspid canine. 



I find nothing very noticeable in regard to the hinder lower 

 milk-teeth of the Ratel ; but the upper canine has a distinctly 

 bifid crown, as in certain Bats, and there are indications of a 

 similar bifurcation in the corresponding lower tootlu Whether 

 this is a primitive or a specialised feature, it is, in this case, 

 difficult to say ; it is almost certainly the former in Bats. 



In referring to the teeth of Galictis as primitive in comparison 

 with those of Mellivora, it should be mentioned that the 

 comparison must be limited to those genera, as the permanent 

 carnassial of Tertiary Mustelines, such as Plesictis, is of the 

 Mellivora- Mustela type. That Mellivora is a more specialised 



