PROFESSOR OWEN ON THE FOSSIL MAMMALS OF AUSTRALIA. 
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trary, to impose their own specific denominations on the so demonstrated distinct kind 
of Wombat. 
§ 13. Mandibular fossils of Phascolomys latifrons. — Of six other mandibular frag- 
ments showing the fore part of the ectocrotaphyte depression, two mutilated right rami 
(Plate XXII. figs. 4 & 5), by the gradual beginning and degree of deepening of that 
depression ( /), agree with the perforate or normal mandible of Phascolomys latifrons. 
The outer orifice of the transverse canal or perforation (ib. ])) holds the same position 
in these fossils : one of them (ib. fig. 4) includes the four anterior molars and the socket 
of the fifth ; the other (fig. 5) includes the four posterior molars. The fore-and-aft 
extent of the series of five sockets, in each specimen, is 2 inches, the depth of the man- 
dible at the back part of the symphysis is (in fig. 5) 6|- lines; in fig. 4 it isl inch 5 
lines. The ectalveolar groove (Plate XIX. fig. 4, u) is narrow. The inner wall of the 
ramus, forming that of the second ( d s) and third (d 4) sockets, descends more vertically than 
in the first described fragment (Plate XX. fig. 2), or in the Tasmanian (Plate XIX. fig. 1) 
and Platyrhine (ib. fig. 2) Wombats. The hind end of the symphysis is on the vertical 
parallel of the interval between d 4 and m 1, or not further back than the middle of m 2 
(Plate XIX. fig. 4, s'). In both these characters the present fossils come nearer to the 
latifront species (Plate XX. fig. 1, s) than to the Platyrhine and Tasmanian Wombats. 
The first molar (d 3) repeats the formal characters of that tooth in the Phase, latifrons. 
I conclude, therefore, that the mandibular fossils under description belonged to a 
“hairy-nosed” Wombat, and one nearer to the existing species than the preceding fossil 
(Plate XX. fig. 2), in which the symphysis appears to have extended as far back as it 
does in Phascolomys platyrhinus (Plate XIX. fig. 2). 
§ 14. Mandibular fossils of Phascolomys Mitchelli. — I now come to mandibular 
fossils which, in the depth of the base of the ectocrotaphyte depression (Plate XXI. 
fig. 5 resemble the Tasmanian and Platyrhine Wombats. Four of these have the 
entire molar series in place. In one (Plate XIX. fig. 5) the extent of the series is 2 
inches 2 lines ; the first molar, however (d 3), agrees in shape and size with that in Phase, 
latifrons (Plate XX. fig. 1, d 3). 
The transverse concavity of the inner wall, continued from the first and second molar 
sockets and upon the symphysis half an inch in advance, more resembles that in the im- 
perforate variety of the Latifront Wombat than in any other mandible of recent species. 
The symphysis (Plate XXI. fig. 6, s) does not extend so far back as in the Tasmanian 
(ib. fig. 1, s) and Platyrhine (ib. fig. 2, s) Wombats. From the fore part of the first 
molar socket to the back part of the upper division (ib. fig. 6, s*) of the symphysial 
surface, in the fossil, measures 1 inch ; and this part of the symphysis is on the vertical 
parallel of the hind lobe of the second molar. The lower division (s) terminates, as in 
fig. 4, below the interval between d 4 & m 1. 
The fore part of the root of the coronoid, in the fossil (ib. fig. 5, q ), stands out from 
the alveolar wall of the penultimate molar, as in Phase, latifrons ; not from that of the 
last molar, as is the rule in the Tasmanian (Plate XXII. fig. 1, q) and Platyrhine (ib. fig. 
2 c 2 
