AUSTRALIAN NATUKAL niSTORT. 141 



GET!7irs DlPROTODO>^. 



- !First pair of upper front teeth broad, scalpiform or chisel-like, 

 without compressed sides. The following teeth much smaller, 

 right below the first pair, and not in a line with them, not unlike 

 the corresponding ones of the native bear. Lower incisors very 

 large, rounded, and tusk-like. 



Genus Zygomatubus. 



First upper incisor with compressed sides, like wombat teeth, 

 of equal width throughout, and forming generally one-fourth of 

 the segment of a circle ; the next pair in a line with the first, not 

 pushed beneath them, much smaller, with straight fangs, and not 

 unlike the same teeth in the -Bettongia campestris — or kangaroo 

 rat. 



Genus Nototheeium. 



The upper teeth of this genus are unknown ; it was founded 

 on certain lower jaws destitute of incisors, but others have since 

 been discovered containing incisive teeth, and these have been 

 added to the genus, so that a definition thereof, according to 

 Owen, stands at present thus — incisors absent, very small, or 

 sometimes very large, compressed, fusiform, and not rounded or 

 tusklike as in the genus Diprotodon. 



The molars vary much in shape, but all appear to have tapering 

 fangs or roots. Premolar very small or absent. 



FaM. PnASCOLOMTIDiE. 



This family comprises the wombats, which retain many of the 

 phalanger characters, but are chiefly distinguished by their peculiar 

 continuously growing teeth. The incisors are two above and 

 below, canines not developed, grinders five in each ramus above 

 and below, the first being a premolar. The crown of very younr 

 wombat molars resembles that of the Diprotodons, but this 

 peculiarity is soon lost when the teeth get into use. Their inser- 

 tion is in this manner that both series when viewed from in frotn 



would form figures like this j K the upper ones turned outwards, 



the lower ones inwards. The incisors above are formed like the 

 first pair of the Zygomaturus teeth, whilst the lower ones 

 resemble the Diprodoton tusks — a curious fact, which points to 

 one common progenitor. It is also interesting to notice that the 

 form of the first pair of cutting teeth in the native bear is more 

 like the Diprodoton's upper incisors, whilst the lower teeth are 

 an exact representation of the fusiform Nototherium teeth. Again, 

 the upper ones of the Bettong closely resemble the Zygomaturus 

 incisors, whilst the lower come near the Diprotodon. It is in 

 this manner that our animals are intimately connected with each 



