2 SIE E. OWEN ON THE TEETH OF A LAEGE EXTINCT WOMBAT. 



fellow, graduallj'- narrowing as it leaves the tooth's socket, to form a 

 ridge, r, r, which expands abruptly at the beginning of the alveolar 

 tract (m) for the molar teeth, which tract is broken away with the 

 missing part of the skull. The intervening edentulous tract 

 bounds, with its fellow, a deep subangular anterior palatine depres- 

 sion (fig. 2, d, d). The breadth of the unworn incisor equals that of 

 the socket of the same tooth in the extinct PTiascolomys medius^. 

 The contour of the premaxillary palatal ridge extending to the 

 molar tract is deeply arched, viewed sideways (fig. 1 r), and is not 

 continued there in an almost straight line, as in Phascolomys 

 mediusf: the depression at the hinder half of the diastema is also 

 much deeper in the present fossil ; the least breadth of this part of 

 the palate is 1 inch. 



The premaxillaries rise at their mid upper suture to about an 

 inch from the prominent alveolar tracts of those bones, and unite to 

 form a ridge, augmenting in height as it extends back ; the frac- 

 tured border probably united with the nasal bones, which are 

 wanting in the fossil. 



The accompanying figures, of the natural size, of this portion of 

 the skull may enable us to dispense with further description. 



Of the animals characterized by the pair of scalpriform incisors 

 the grounds for referring the present large extinct kind to thQ 

 Marsupial rather than the Rodent order have weighed with me ; 

 and until further evidence, especially ihat supplied by a molar 

 tooth, or teeth, negativing the present conclusion, be received, I 

 place it in the Wombat family. 



The specimen indicates, therein, a somewhat larger animal than 

 the Phascolomys medius, Ow., but one less than the type of the 

 subgenus PJiascolonus J. The chief difference from phascolomydian 

 species, both recent and extinct, of less magnitude, has suggested 

 the nomen specificum. 



EXPLANATION OF PLATE I. 



Portions of the premaxillary bones, including the incisors : nat. size. 



Fig. 1. Left side view. 



2. Under or palatal surface. 



3. Back view, showing pulp -cavities, i\ of incisors. 



Discussion. 



Dr. H. WooBWAED regretted that he had been unable to bring the 

 cast, but would produce it at the next Meeting. The original 

 specimen is in the Sydney Museum. Without molar teeth it is 

 difficult to compare the specimen with other species. There was 

 some resemblance to Biprotodon, but it was difficult to go into this 

 in the absence of the cast. 



* Fossil Mammals of Australia, 4to, pi. 1. fig. 6. 



t Op. cit. pis. Ivii., Iviii. fig. 3. 



J Op. cit. vol. i. p. 339, pis. Ivii.-lix. 



