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Genus Phascolomts. 



Species exceeding the existing ones in size. 



In the preceding section I applied the cranial, mandibular, and dental characters of the 

 existing species of Wombat to the determination of the fossil species resembling them 

 in size ; in the present are given the results of an easier task, viz. the determination 

 of extinct Wombats of markedly superior size to any now living ; and I shall describe 

 the fossils as the species they represent progressively predominate in bulk. 



§ 1. Phascolomys medius, Ow. — This species is represented by a lower jaw, fractured 

 at both ends, presented by Sir Chaeles Nicholson, Bart., to the Geological Society of 

 London ; also by the fore part of the upper jaw of two individuals and by the right 

 ramus, fractured at both ends, of the lower jaw, obtained by Edwaed S. Hill, Esq., from 

 freshwater deposits exposed in the bed of a tributary of the Condamine River, at Eton 

 Vale, Queensland: the latter were submitted to me in 1865, and have been liberally 

 presented, with other Queensland fossils, to the British Museum by Sir Daniel Coopee, 

 Bart. All these fossils are in the usual heavy, petrified, rolled, and more or less mutilated 

 condition of such remains from the above formation and locality. 



The first to be described (Plate LVII. figs. 2-7) consists of so much of the premaxillary 

 (22) and maxillary (21) bones as includes the sockets of the incisors (i) and of the first three 

 molars (d 3, d 4, m 1, fig. 2), with part of that of the fourth, m 2. The incisors are broken 

 off at the level of their alveolar outlets (fig. 6, i) ; the first and second molars, left side, 

 show their natural grinding-surface ; part of that of the following tooth is broken ; the 

 rest of the molars are more or less mutilated or wanting. 



The superiority in size of the present extinct species to the two largest of the 

 existing Wombats will be seen by comparing the above-cited figures, especially fig. 2, 

 Plate LVII., with the corresponding parts of the skull of Phascolomys latifrons (ib. 

 fig. 1) and of Phascolomys platyrhinus (Plate LVIII. fig. 1); it needs not to introduce 

 the smaller Tasmanian Wombat into the comparison. 



The following admeasurements give the degree, or value, of the character from the 

 size of teeth and extent of diastema of the species above cited: — 







P. medius. 



P. jolatyrMnus. 



P. latifrons. 







inches, lines. 



inch, lines. 



inch, lines. 



Antero-posterior 



extent of grinding-surfaces of j 











1 6 



1 2 



1 



Antero-posterior 



extent of diastema (I to i) . . 



2 6 



1 7 



1 9 



In the relative length of the interval between the socket of the incisor (Plate LVII. 

 fig. 2, i) and that of the anterior molar (d 3), the present fossil resembles the latifront 



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