ITS DISPUTED AFFINITY. 



443 



as indicative of robustness ; also the broad and high coronoid 

 process, and the pedunculate condyle placed below the level 

 of the grinding teeth (above, p. 432). They are all regarded 

 as proving a carnivorous type. They were not overlooked in 

 my former communication : — ' The characters of the jaw are 

 so peculiar, and in some respects of so mixed and complex a 

 nature, that they ought to be weighed with caution, in con- 

 junction with the teeth, in forming any opinion of the 

 affinities of Plagiaulax. The low position of the condyle is 

 so pronounced, and the elevation of the coronoid above it so 

 considerable, that, regarded per se, supposing no teeth had 

 been discovered, they might have been considered to imply, 

 with some degree of certainty, a preclaceous animal.' ' But 

 there were other characters, which, taken in conjunction with 

 the jaw, appeared to me to counterbalance these indications 

 — namely, the moderate extent and low elevation of the 

 coronoid above the grinding plane of the teeth ; the long 

 neck and horizontal projection of the condyle behind the 

 coronoid ; the form of the condyle itself ; and the absence of 

 a stout angular process behind it. With one exception, I 

 shall consider these mandibular characters briefly. 



And first, as regards the shortness of the horizontal 

 ramus in proportion to its depth. I refer my reader to 

 fig. 13 of PI. XXXIV., representing the side view of the 

 lower jaw of the Aye-Aye. A glance will satisfy him 

 that the horizontal ramus is much deeper in proportion to 

 the length in this form than it is in P. BecJclesii. The fact 

 is so obvious that I do not think it necessary to enter upon 

 the metrical details. Commonly we connect the idea of 

 robustness in the lower jaw with the form and section of the 

 mandible presented by the Hyaena and Tiger. If the sections 

 in my original paper are referred to (PL XXXIII. figs. 2 & 3), 

 it will be seen that they are totally different. The jaw of 

 Plagiaulax in this respect also closely resembles that of the 

 Aye-Aye. 2 



The coronoid process comes next for consideration. For 

 the details of my description of it I refer my readers to 

 p. 418 of my former paper. It is there stated that ' in 

 general form the coronoid process in Plagiaulax resembles 

 more that of the predaceous marsupials, and of the Ursine 

 Dasyurus especially, than that of the herbivorous families. 

 It differs very markedly from the elevated strap-shaped 



1 See antea, p. 424.— [Ed.] 



2 In the Koala (Phascolarctvs cine- 

 reus), in which the procumbent incisors, 

 as already observed above (p. 436), are 

 projected with an inclination resembling 

 that of Plagiaulax minor, the horizontal 



rami of the lower jaw present great 

 depth in proportion to the length, with 

 a compressed section. (Waterhouse, 

 ' Mammalia,' vol. i. p. 264.) But the 

 ascending ramus, in that genus, is on a 

 totally different plan of construction. 



