BY C. W. DE VIS M.A. 



115 



Nototheriuru on the safe ground of structural correspondence with 

 the lower (the correspondence being the same in kind as in Owenia) 

 are by no means rare — are, in fact, more abundant than the mandi- 

 bular. We have twenty-two examples of them, varying according 

 to age and species (a somewhat similar disparity in the number of 

 Diprotodon jaws may be noted in passing), and with them almost 

 as many fairly identifiable maxilla? and other cranial relics. 

 Several entire crania have been found, but so decomposed as to 

 defy all attempt at reconstruction. They show, however, clearly 

 enough that the physiognomy of the animal was not greatly 

 different to that of Diprotodon, and thus quite unlike that of Zygo- 

 maturus with its substructure of massive expanded nasals and 

 zygomatic arches, beetling frontals and retracted jaw bones. 



It may be well, though unnecessary, to add that the best pre- 

 served series of these maxillary teeth correspond closely in length 

 and in relative breadth with the most complete of the mandibular sets. 



In view of such correspondence, structural and numerical, it 

 would be taking an unnecessarily low ground of argument to ask 

 in turn to what other animal all these upper jaws are to be referred. 



The Nototherium upper premolar is essentially similar to, but as 

 usual broader and more regularly triangular than, the lower. It 

 has one large sub-central and sub-conical cusp longitudinally con- 

 stricted in the middle towards the culmen, and wears down t > an 

 obliquely transverse curved tract of dentine more or less contracted 

 mesially. It has a narrow posterior talon which is on the inner 

 side continuous or nearly so, with an anterior talon continued on 

 that side to the front angle of the tooth, but not around it, or if 

 around it, not on the outer side. 



Enough has perhaps been said to warrant the following con- 

 clusions : — 1st. That the upper premolar of Nototherium shows a 

 departure not morn tnan generic from that of Diprotodon, and 

 consequently that both genera belong to one family, the Noto- 

 therida? which also includes Owenia, and, perhaps, Sthen- 

 omerus. 2nd That Zygomaturus is a good genus, and that its 

 affinity with the Nototherida? is, to say the least, doubtful. 



