182 
PROFESSOR OAVEN ON THE EOSSIL MAMMALS OF AUSTRALIA. 
deserve particular attention ; they are generally specific, and of consequence in the deter- 
mination of recent and fossil species”f. 
In the skull of the AVombat from Tasmania [Phase, vombatus ), figured in the same 
Paper J to illustrate the palatal and other characters afforded by a basal view of the 
cranium, the foramina are oval, the base which is behind being rounded ; but the small 
anterior end of the oval is so nearly pointed as to suggest the term “ triangular.” In 
two skulls since compared these foramina present the same shape and proportions ; in two 
smaller and younger skulls of Phase, vombatus they are relatively smaller, and rather 
elliptical than oval. In two skulls of Phascolomys p latyrliinus in the Collection of the 
British Museum I note that the postpalatal foramina are longitudinally elliptical or 
oblong in one, and are triangular in the other ; the larger continental bare-nosed species 
showing the same variety as the smaller Tasmanian AVombat. This, therefore, is an 
exception to the general rule of the specific value of the postpalatal character §. The 
larger, especially the longer postpalatal varieties, encroach more forward and come 
nearer to the transverse parallel of the anterior wall of the hindmost socket. Allowance 
must be made for this variation. 
In two skulls of Phascolomys latifrons the postpalatine foramina are relatively larger, 
especially longer, than in either the Tasmanian or Platyrhine AVombats, and they are 
rounded anteriorly, but less broad there than behind. 
Dr. Murie || notes the larger size of the postpalatine foramina in Phase, latifrons as 
compared with Phase, platyrhinus , and I therefore attach the more value to the cha- 
racter, as probably being more constant in the latifront species. It must, however, be 
considered in connexion with the more constant cranial characters. The following 
fragmentary fossil from the “ breccia-cave ” of AVellington Valley exemplifies the need of 
keeping this relation in view. The fossil consists of a left maxillary and palatine, with 
the molar alveoli, fractured at both ends (Plate XVII. figs. 7, 8) ; the anterior fracture 
exposes the socket of the first molar, d 3 . By the anterior contraction of the palate and 
by the size and proportions of the alveoli the fossil resembles Phascolomys platyrhinus', 
by the parallelism transverely of the fore part of the postpalatal aperture and the same 
part of the posterior alveolus, and by the height of the maxillary below the malar process 
of that bone (fig. 7, 21 *), it resembles Phascolomys latifrons. By the combination of both 
characters it proves its relationship to Phascolomys Mitclielli ; as in that species the prezy- 
gomatic ridge is less prominent or definite, and is higher placed than in existing AA r ombats. 
§ 10. Palate and upper molars , Phascolomys Mitch elli, from freshwater deposits , 
t “ On the Osteology of the Marsupialia,” Trans. Zool. Soc. vol. ii. p. 388. 
i lb. plate lxsi. fig. 6. 
§ The skull of the AVombat, from New South AVales, with “ two large triangular holes in the end of the 
palate,” was probably the only one in the British Museum Collection at the date of Dr. Gray’s comparison 
of it with the smaller Tasmanian species, which he believed to be differentiated by the “ two moderate-sized 
oblong holes in the hinder part of the palate.” (“ Some Observations on the skull of Phascolomys vombatus, ’ 
by J. E. Gray, E.R.S., Proc. Zool. Soc. 1847, p. 41.) 
|| Loc. cit. p. 844. 
