138 ATJSTEAXIAN NATURAL HISTORX. 



little animals just mentioned is of so exceptionable a character 

 that they cannot Aveil be included in the group Avith more highly 

 developed teeth. Eor the sake of arrangement, however, the 

 tarsipes is added to the phalangers and the myrmecobius to the 

 dasyures. 



Eollowing the clue thus received, we arrive at the dentition of 

 tlie aberrant phalangers represented by the genus Thylacoleo. 



This supposed marsupial lion, believed to have been the "fellest 

 of the fell," was, after all, a harmless creature, which is proved 

 by his weak incisors, small canines, and the highly iniiected scoop- 

 like angle of the lower jaw. This animal bruised his food with 

 a formidable premolar tooth, whereof one was developed m each 

 ramus above and below. Cuvier's well-known sentence about 

 the molars of a mammal, explaining its character and position in 

 the system, failed in this instance. A much worn large premolar 

 in the Australian Museum, and an upper pair with perfectly flat 

 grinding surface in Professor Owen's possession — a present from 

 Dr. Greorge Bennett — have probably convinced anatomists that 

 the AT.ew I took first of the herbivorous habits "of this " lion in 

 phalanger hide" was a perfectly correct one. The incisors are 

 simply large editions of the typical phalanger's front teeth, such 

 as may be examined in the native bear, the yellow-bellied flying 

 phalanger, or the northern dactylopsila or striped phalanger. It 

 would be waste of time to describe them in detail ; those gentle- 

 men who take sufficient interest in the matter can get a Phasco- 

 larctos or " native bear" skull any day, and those who do not care 

 about it will perhaps feel thankful for being spared the infliction 

 of a long description. The Thylacoleo was just three times the 

 size of a native bear, and if this scale is borne in mind the incisive 

 dentition can be reconstructed without trouble by those interested. 

 The great premolar corresponds to the same tooth of the phalan- 

 gers, and makes its appearance early. The first molar below is, 

 however, the tooth of a carnivore, and corresponds to that of the 

 Sarcophilus, so does the last tooth above. The last molar, like 

 that of all the marsupial carnivores, stands transversely and 

 across the palate. The second or last molar below is a small 

 tubercular tooth, and quite unlike the last and largest trenchant 

 one in the pouched flesh-eaters. The canine above is an enlarged 

 example of the canine of Bettongia rufescens. The canines 

 found vary, and may be those of several species of " pouched 

 lions." They are placed far into the palate, and are more or less 

 covered by simple, single-rooted, and blunt premolars, the crown 

 of which resemble the head of a common wrought nail. 



In the true phalangers the upper canines and premolars, ±^os. 

 2 and 3, are generally well developed, the first premolar being 

 lost in early life. 



