PEOFESSOR OWEN ON TIIE FOSSIL MAMMALS OF AUSTRALIA . 



175 



of the whole lateral margin of the bone. The basal breadth bears almost the same 

 proportion to the length of the nasals as in the first cited skull, 



§ 3. JS^isal bones in Phascolomys platyrhinus, Ow. — The Platyrhine Wombat, in the 

 absence of postorbital processes, the shortness of the naso-maxillaiy suture, and the 

 deep emargination of the fore part of the nasal process of the premaxillary, is more 

 nearly allied to Phase, vombafus than either of these species are to Phase, lafifrons* ; but 

 the nasal bones (fig. 3, 15) are relatively broader in the Platyrhine than the Tasmanian 



Fig. 3. 



Nasal bones and their connexions, Phascolomys platyrhinus, Ow. 



Wombat, the outer basal angles approaching as near to the lacrymal tubercles (ib. 73) 

 with a greater relative breadth of the skull at that part. In one skull the lateral 

 borders of the nasals have the same undulatory course, but more feebly marked than in 

 the second variety of Phase, vombatiis (fig. 1). In a second the suture between the 

 nasals (is) and premaxillaries (22) runs as in tig. 3. There is a narrow and irregular 

 intrusion of the frontal at the middle of the fronto-nasal suture, sometimes at the 

 expense of the right (as in fig. 3), sometimes of the left nasal bone. The breadth of 

 the base of both bones equals five sevenths of the length of the nasals in two specimens, 

 and four fifths in a third. The apices (15), projecting anterior to the naso-premaxillary 

 suture (22), are blunter than in the first variety of Phaseolomys vombatus. The width 

 or breadth of the nasals, at their base or fronto-nasal suture, begins to diminish at once, 

 as they advance, by the converging course of the naso-maxillary (15-21) and naso-pre- 



* This relation is pointed out by Dr. Murie, who remarks : — " Phascolomys latifrons shears off from the 

 common form of Wombat and reverts to the true marsupial type in several particulars " {loc. cit. p. 800). These, 

 however, he does not cite ; and I may have to note some points in which it seems rather to diverge from the 

 common character. 



2 a2 



