110 FOSSIL MAMMALIA OF THE 



peculiarity of grooving, but the grooves in the same direction, with some sUght differ- 

 ence of position, and associated with the same trenchant hind border of the canine, that, 

 therefore, it must be the jaw of a frugivorous or mixed-feeding Quadrumanous animal, 

 I must have objected, as a disciple of Cuvier, and a behever in his 'Law of Correlation,' 

 that the grooved and trenchant canines were associated in the Mesozoic fossil with large 

 carnassial and small and few tubercular molars ; whereas in the existing Quadrumana 

 the grooved and trenchant canines are associated with several and large tubercular 

 molars. 



Similarly, the grooved and trenchant premolars of Plagiaulax are associated, in that 

 Mesozoic fossil, with large laniaries and few and small tubercular molars ; whereas in the 

 existing " Macropoda (Van der H. = Poephaga, Owen)" the grooved and trenchant pre- 

 molars are associated with many and large tubercular molars, besides being dissociated 

 from large laniaries. 



To me, therefore, the affinity of Plagiaulax to Hypsiprymnus, and the concomitant 

 assumption of the saltatorial and herbivoious character of the small extinct Mesozoic 

 Marsupial, are not demonstrated in any degree ; the demonstration of the carnivority of 

 Plagiaulax appears to be much more ample. 



Referring to the page quoted by Mr. Boyd Dawkins as proof of my opinion of the close 

 alliance of Microlestes to Plagiaulax, I find the following : — " Amongst existing Mammals 

 some of the small molars of the marsupial and insectivorous Myrmecohius of Australia offer 

 the nearest resemblance to these fossil teeth, but a still closer one is presented by the 

 small tubercular molars of the extinct Mammal called Playianlax." {' Pateontology,' 

 1st ed., p. 302; 2nded, p. 339.) 



Now, here is no affirmation of alliance, close or loose, between Microlestes and 

 Playiaulux, but simply a statement of a resemblance between certain of their teeth. 

 To be able to affirm of a ' close alliance' between Plagiaulax and Microlestes, the 

 Palseontologist must know, not only the degree of resemblance between certain of their 

 teeth, but also that between the rest of their dental system. 



One must first learn in what numbers the small tubercular teeth of Microlestes were 

 present in its jaws, and next with what other kind of teeth they may have been 

 associated. 



If my inferences be just and the conclusions they support be honoured by acceptance 

 in Palaeontology, it will not imply that my opponents had " fallen into errors of observa- 

 tion and description " ' so much as it will " expose the fallacious train of reasoning which 

 had led them astray ; '' " for which they " have no excuse to plead on the score of haste or 

 want of due consideration." ^ Should Plagiaulax be permitted to rest, after the facts 

 and reasonings on the fossil evidences at my command, in the paucidentate section of 

 diprotodont Marsupials, with Thylacolco, amongst the predaceous feeders on flesh, and 



' Falconer, opp. citt., pp. 3.50, 433. 

 2 lb., ib. ^ lb., ib. 



