154 



The fact is patent ; but the inference has been called in question. 



Dr. Falcon kr writes, in June 1802, "Next, as regards the depressed position of the 

 condyle— below the level of the grinding-tceth. The author of 'Palaeontology' states 

 that it is ' a character unknown among any herbivorous or mixed-feeding animal. 1 

 again refer my reader to the figure (pi. 34. fig. 13) of the lower jaw of the Aye-aye"*. 

 This figure is essentially the same as that in my Memoir read before the Zoological 

 Society, January 14th, 1802 (fig. 9). Prior to that date the depressed position of the 

 condyle to the level of the grinding-teeth (fig. 9, b) was a character unknown in any 

 herbivorous or mixed-feeding animal ; it is still so unknown as depressed below that 

 level, such as we see it in Plagiaulax (fig. 10). Dr. Falconer, proceeding with his evi- 



Fig. 9. Fig. 10. 



size (Zool. Trans, vol. v. pi. 20. fig. 9, Memoir of Mandible of " Plagiaulax Becklesii, magnified four 



January 14, 1862). diameters" (after Falconer, XI. pi. 34. fig. 1). 



dence of the herbivority of the gnawing Lemur and his comparison of its mandible with 

 that of Plagiaulax, admits that " the condyle looks still more depressed in Plagiaulax 

 Becklesii ; but this is, in part, owing to the inflected margin of the angle being broken 

 off in the fossil, while it is entire and salient in the recent form, thus elevating the con- 

 dyle above the lower plane of the ramus, and leading to an appearance of a greater 

 amount of difference than exists in nature "f. 



Here we are at issue on a matter of fact. I affirm that the condyle (b. fig. 10) in Plagi- 

 aulax would not be so elevated above the lower plane of the ramus if the angle (a, fig. 10) 

 were entire and salient, because the saliency has an inward, not a downward, direc- 

 tion. The correspondence in this respect, as well as in the low position of condyle, of 

 Plagiaulax with the carnivorous Thylacoleo, Dasyures, and Thylacines, and its difference 

 from the herbivorous marsupials (fig. 0) and larvivorous Lemur (fig. 9) is as clearly 

 demonstrated in the Purbeck fossils, as if the inflected angle had received no fracture 

 whatever. 



For other differences of mandibular structure and configuration between Plagiaulax 

 and Chiromys, invalidating Dr. Falconer's argument in favour of a common herbivorous 

 or rodent nature associated with a common depressed position of condyle, I refer to figs. 

 9 & 10. 



In reference to the subject of the latter illustration, Dr. Falconer has remarked, " Pro- 

 * X. p. 361 ; XI. p. 445. t X. p. 361 ; XI. p. 446. 



