2 NOTOTHKEIA AND ALLIED ANIMALS— A REJOINDER, 



We therefore desire to add the present note to our 

 previous papers in order to reply to certain remarks made 

 by Mr. Heber Longman in his recent interesting contribution 

 to the memoirs of the Queensland Museum, (2) on Eiiry zygo- 

 ma dunense. (1920, p. 65.) 



The extent to which generalisation obtained among 

 Nototherian animals can only be appreciated by those who 

 have for some reason or other paid special attention to 

 the matter, and, therefore, we must be pardoned for giving 

 in detail the following item of cranial morphology. 



The zygomatic arch of a Nototherium such as that 

 of Nototherium tasmanicum. leaves the occiput under condi- 

 tions that are not exactly repeated by either Macropus (Kan- 

 garoos), Phascolomys (Wombats), or Phascolarctus (Native 

 Bears), but upon the whole they are those of M-cicropus. 

 It descends into the orbit at a vertical line at least 50 mm. in 

 advance of the premasseter process (not so in A^. 7nitchelli) , 

 while in the Kangaroo this process outwardly 'underprops the 

 posterior third of the orbit. It does not reach it by 8 mm. 

 in the Native Bear and 10 mm. in the Wombat. Owing to 

 the heavy developed premasseter process the morphology of 

 the orbit here departs from that of the Kangaroo, misses 

 the Wombat outline, but with generic characteristics assumes 

 in exaggeration that of the Native Bear, which it continues 

 to follow with added closeness to the end of the skull, includ- 

 ing the lateral incisors, but not the nasal regions. Here, 

 then, in a few inches of space we have the characters of 

 three modern animals in generalised association in the skull 

 of a single Nototherium, and might we not then expect that 

 equally generalised creatures of the same age should show 

 intergrading dental characters that would render the strict- 

 est terms of modern classification untenable? 



Our use of the word Phascolonus was intended to imply 

 that the jaws called Nototherium dunense conformed even 

 more strongly to the Phascolonian type than they did to the 

 Nototherian. In other words we considered the Wombat 

 characters so accentuated in this mandible that it would be 

 eventually classified with a type more generalised than Noto- 

 therium, and one that more closely approached the common 

 progenitor of gigantic Wombats and Nototheria. Others be- 

 sides ourselves have found such a creature thinkable; for 

 instance, the late Richard Lydekker wrote thus of the family 

 Nototheridse: — "This family connects Phascoloinyidse with the 



^2) Heber A. Longman. A New Gen-'us of Fossil Marsupials. Mem. 

 Qld. Mus. Vol. VII., pt. II. 



