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XI. On the Fossil Mammals of Australia. — Part VII. Genus Phascolomys : species 
exceeding the existing ones in size. Jig Professor Owen, F.B.S. &c. 
Received March 25, — Read April 18, 1872. 
In a former communication* 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 determi- 
nation 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. Phascolomgs viedius, Ow. — This species is represented by a lower jaw, fractured 
at both ends, presented by Sir Charles 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 Edward S. Hill, Esq., from 
freshwater deposits exposed in the bed of a tributary of the Condamine Biver, at Eton 
Vale, Queensland: the latter w T ere submitted to me in 1865, and have been liberally 
presented, with other Queensland fossils, to the British Museum by Sir Daniel Cooper, 
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 XXXII. 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 XXXII., with the corresponding parts of the skull of Phascolomgs latifrons (ib. 
fig. l)and (A Phascolomgs platgrhinus (Plate XXXIII. 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 
P. latifrons. 
inch, lines. 
Antero-posterior extent of grinding-surfaces of) 
d 3, d 4, m 1 j 
Antero-posterior extent of diastema (l to i) . . 
* Philosophical Transactions, 1872, p. 173 
above cited: 
— 
P. medius. 
P. plati/rhinus. 
inches. 
lines. 
inch, lines. 
1 
6 
1 2 
2 
G 
1 7 
2 X 
MDCCCLXXII. 
