444 PLAGIAULAX. 



coronoid of Hypsiprymnus and the other herbivorous mar- 

 supials. It is to be remarked, however, that it is less elevated, 

 and its surface of less area, than in the predaceous genera, 

 whether marsupial or placental.' Here, it will be observed, 

 the comparison was restricted to marsupial forms, beyond 

 which I did not then think it necessary to carry it. If ex- 

 tended to the Aye-Aye (PL XXXIV. fig. 13), additional 

 light is thrown upon the character. In both, the anterior 

 edge reclines at an angle of about 45° ; in both, the summit is 

 not much elevated above the grinding-plane of the teeth. 

 The appearance of elevation, which is at first sight suggested 

 by the coronoid of Plagiaulax, arises from the great depth of 

 the sigmoid notch and the low position of the condyle. If 

 fig. 1 of PL XXXIII. be referred to, it will be seen that the 

 process itself is not raised much above the summit of the 

 premolars. There is a further agreement between the Aye- 

 Aye and Plagiaulax in the amount of area occupied by the 

 surface of the coronoid. This is partly disguised, in the 

 lower jaw of the former, by the broad neck of the condyle 

 and the shallowness of the lunate notch between it and the 

 coronoid ; if the notch were deepened, as indicated by the 

 dotted line (/), the resemblance would be complete. I do not, 

 therefore, admit the force of Professor Owen's remarks, as 

 significant of carnivore affinities, that ' the lower jaw is short 

 in proportion to its depth, sending up a broad and high 

 coronoid process for the adequate grasp of a large temporal 

 muscle' — seeing that all these characters are combined in an 

 existing gliriform Lemur, which is not a carnivore. The 

 descriptive terms applied to the coronoid would be suitable 

 for that of a Tiger or Stoat, but they seem hardly applicable 

 to the process of Plagiaulax. 



The author of 'Palaeontology' lays stress on the low 

 position of the condyle and its long horizontal neck : ' The 

 condyle is placed below the level of the grinding-teeth, a 

 character unknown in any herbivorous or mixed-feeding 

 Mammal; it is pedunculate, as in the predaceous Marsu- 

 pialia ; whilst the lever of the coronoid is made the stronger 

 by the condyle being carried further back than in any known 

 carnivorous animal.' But it is not a little remarkable that 

 he is silent regarding the form of the condyle itself, the most 

 important of all the mandibular characters after the teeth ; 

 for the peduncle, on which he lays weight, is, like the fang of 

 a tooth, but the stalk upon which the organ performing the 

 function is borne. I think it necessary therefore to call 

 attention to the remarks on the subject contained in my 

 former paper. In the true carnivorous type the condyle 

 shows more or less of a cylindrical or terete surface, having 



