PROFESSOR OWEN ON THE SPECIES OF PHASCOLOMYS. 349 
lacrymal tubercles, with a greater relative breadth of the skull at that part. In two 
skulls the lateral borders of the nasals have the same undulatory course as in Phasco- 
lomys vombatus, but more feebly marked. There isa narrow and irregular intrusion of 
the frontal at the middle of the fronto-nasal suture (11), sometimes at the expense of 
the right, sometimes of the left nasal bone. The breadth of the base equals five sixths 
of the length of the nasals in two specimens, and four fifths in a third. The apices pro- 
jecting anterior to the naso-premaxillary suture are short and blunt, as usual in Phasco- 
lomys vombatus. ‘The width of the nasals at their base, or fronto-nasal suture, begin 
to diminish at once as they advance by the converging course of the naso-maxillary and 
naso-premaxillary sutures. In not one of the three specimens before me is “ the width 
of the nasals continued forward beyond their middles”’. 
In Phascolomys latifrons, where the breadth of the fore part of the frontals is made 
to contrast with the narrowness of the rest of the bones by the outward extension of the 
postorbital processes, the nasals (Pl. LI. fig. 5, 15) present a more regular triangular 
form through the prevailing transverse course of the fronto-nasal suture (11-15), and the 
more regular convergence of the lateral margins of the nasals to the fore ends of the 
naso-premaxillary sutures (15-22). Beyond these the lateral margins converge more 
rapidly to the apices, which extend freely forward further than in the two preceding 
species. The breadth of the nasals at the base of their free extremities is greater than 
in the other two Wombats, and the upper surface is flatter. 
In one of four skulls before me of Phascolomys latifrons the left frontal breaks the 
transverse course of the fronto-nasal suture by a short pointed process or wedge between 
the two nasals; in a second skull the right frontal sends forward, in the same way, a 
more obtuse triangular process; in the type skull (Zool. Trans. vol. iii. pl. xxxvii. 
fig. 4), both frontals contribute equal shares to the wedge; in two later-acquired spe- 
cimens the suture is uninterrupted. The transverse course of the fronto-nasal suture is 
constant and characteristic of Phascolomys latifrons. Moreover the suture (11-15) is not 
separated from the lacrymal (73) as it is in Phascolomys platyrhinus and Phascolomys 
vombatus, by the maxillary (21); or if, as in an exceptional skull, or on one side, the 
maxillary goes back as far as the frontal, it is by a very narrow strip. 
The extent of the naso-maxillary suture (ib. fig. 5, 15-21) equals, in Phascolomys lati- 
frons, that of the naso-premaxillary suture (15-22). These differences in the connexions 
of the nasals are more significant of specific distinction than is the shape of the 
bones. The naso-maxillo-premaxillary suture is very slightly concave outwardly; the 
free border of the nasal, beyond the suture, is of greater extent in the hairy-nosed than 
in the bare-nosed Wombats. 
There would be no doubt in determining Phascolomys latifrons by the naso-maxillo- 
premaxillary part of the skull, at least as being distinct from the other two known 
recent species, if even the still more characteristic part of the frontal bones were want- 
ing. There might be more difficulty in pronouncing from the same part of the skull 
1 Murie, loc. cit. at p. 803. 
