4 NOTOTHERIA AND ALLIED ANIMALS— A REJOINDER, 



an enormous element of variation, from which the teeth, 

 in addition to the other parts of the skeleton, could hardly 

 escape the process of remoulding, and in the absence of a 

 complete series of such changes, even in one group of ani- 

 mals, quite apart from the sum total, we tentatively classified 

 known material in terms of the most obvious trend characters. 

 If all extinct creatures had first been classified in groups, 

 and as knowledge increased genera and species had been 

 eventually created within the groups, how much confusion 

 would have been avoided! 



All classification is man-made, and in essence chiefly 

 intended to avoid ambiguity when the name of an animal is 

 mentioned. Most of us admit this, and yet rise up in arms 

 immediately we are asked to act upon our conviction. Accord- 

 ingly, we did not expect a ready acceptance of our group 

 taxonomy, yet nevertheless it is as sound as if we had called 

 the White Rhinoceros of to-day "A large-horned Rhinoceros" 

 and the Chittagong animal a "Small-horned Rhinoceros.*' 



RECAPITULATION. 



(1) We are convinced that the several groups of more 

 or less generalised animals lived in the Australian 

 Zoogeographical province and that the names Dipro- 

 todoij, Nototheriimn, Phascolonus, Eury zygoma, 

 etc., stand as outpost flags to a largely unexplored 

 realm. 



(2) That De Vis' estimate of seven or eight groups may 

 yet prove to be feasible. 



(3) That the most generalised groups have yet to 

 be re-constructed. 



(4) That in view of these facts it is better to seek 

 the elucidation of the groups than it is to argue 

 over the sub-divisions of such groups. According- 

 ly, we write, and always have written, in that spirit, 

 and without any desire to under-estimate the works 

 of others. 



EXPLANATIONS OF PLATES. 



Plate I. 



Side view of the articulated skeleton of Nototherium 

 "tnitchelli. The specimen, although not perfect in all details, 

 shows, for the first time, the general outline of this animal. 



