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Plate LI V.), and resembles the Hairy-nosed Wombat in the size of its molars, which is less 

 than in Phascolomys ylatyrh'unis (Plate LIU. fig. 2, d 3 , d*,mi). But the following 

 differences present themselves in the comparison of the present fossil with the corre- 

 sponding part of the mandible of Phascolomys latifrons. In that species the upper 

 transversely concave intermolar part or surface of the symphysis does not extend back- 

 ward beyond the alveolus of the second molar ; at the third molar the inner wall of the 

 jaw soon changes its concavity for a convexity bending down to the back part of the 

 symphysis. In Phascolomys platyrhinus the concave upper surface of the symphysis 

 extends further back, and this character is exaggerated in the fossil ; for the inner wall 

 of the socket of the third molar (Plate LIV. fig. 2, m 1) arches inward as it descends, con- 

 tinuing the diastemal transverse concavity to that part of the molar series where the 

 hinder fracture of the present fossil has occurred, exposing the long curved implanted 

 part of the third molar (m i, fig. 3). 



Another difference is seen at the under part of the symphysis of the fossil (Plate LVI. 

 fig. 4) as compared with that in the latifront species (ib. fig. 3). In this the longitudinal 

 contour is convex, concurrently with the greater general convexity of the curve of the 

 lower border of the mandible (Plate LII. fig. 3) ; in the fossil (ib. fig. 7) the lower 

 surface of the symphysis runs straight, or very nearly so, from the hind fracture to 

 the outlets of the incisive alveoli (.V), along a preserved symphysial extent of 2 inches 

 8 lines. It is interesting to see that here, again, the fossil resembles the Platyrhine species 

 (Plate LII. fig. 2), the older spelaean form combining to a certain extent characters kept 

 apart in still existing species of Wombat. Nevertheless the more essential resemblances 

 are to the Phascolomys latifrons. The pair of subsymphysial foramina (Plate LVI. 

 fig. 4, r) characteristic of the Wombats are wider apart (4 lines) than in the Platyrhine 

 (ib. fig. 1, r) and Tasmanian (ib. fig. 2, r) species, and show rather the latifront character ; 

 they have the usual relative position to the fore and hind ends of the symphysis. 



The specific distinction between the broad-fronted (Plate LII. fig. 3) and other exist- 

 ing Wombats (ib. figs. 1 & 2) afforded by the ascending ramus of the mandible induced 

 at tention to all the cave fragments of that part of the lower jaw, and led to careful 

 removal of the matrix from both the outer and inner depressions. This brought to light 

 the modification of the lower part of the ectocrotaphyte depression (f) shown by the 

 subject of fig. 6, Plate LII. In the minor depth of the base or lower part of that de- 

 pression the fossil mandibular fragment agrees with Phascolomys latifrons (ib. fig. 3,/'), 

 and more especially with the variety above noted with the absence of the transverse perfo- 

 ration (Plate LII. fig. 3). The part of the base, or below the base, of the coronoid in 

 the fossil where the canal opens externally in the normal mandibles of Phase, latifrons* 

 is entire ; it is also less depressed there than in the perforate variety. From this and 

 the normal mandible of the latifront species the fossil (Plate LII. fig. G) differs in the 

 relative position of the anterior beginning of the " ectocrotaphyte ridge " (h) or that 

 bounding below the ectocrotaphyte depression (f). In the three recent species (ib. 



* Trans. Zool. Soc. vol. iii. plate xxxvii. fig. 5. 



