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The subject of figs. 1 & 2, Plate LXXXV., was obtained by Henry Hughes, Esq., from 

 the freshwater deposits exposed in the beds of creeks in Darling Downs. It is now in 

 the Museum of the Natural-History Society of Worcester, to the Council of which Society 

 I was indebted in 1858 for the permission to take the above description and figures of 

 this instructive and, at that time, unique fossil. 



To Sir Daniel Cooper, Bart., I have since been indebted for the opportunity of 

 describing and figuring a larger proportion of the left mandibular ramus of the same 

 species of Proterrwodon, with the molar series at nearly the same stage of attrition. It 

 was discovered by Ed. S. Hill, Esq., in the freshwater deposits of Eton Vale, Queensland. 

 Of this fossil I give an external view (ib. fig. 3), in which it will be observed that, as in 

 the foregoing example, the crown of m i is more worn (has borne more of the work of 

 mastication) than that of the antecedent molar (d 4). I have noted the same circum- 

 stance in a Macropus major of similar age. This may not relate to an earlier period 

 of m 1 coming into the line of work than the molar which precedes it, but more probably 

 is due to the greater degree of pressure upon a tooth nearer the centre of motion of 

 the mandible. The last molar (ib. figs. 3 & 4, m 3) shows the narrower hind lobe (b) : 

 the seemingly broader prebasal ridge (f ) than in m 2 may relate to the less amount of 

 attrition in m 3. The links are low and ill-defined in this, as in the type specimen. 

 There is a slight bulge behind, but no indent marking a postbasal ridge in the hind- 

 most molar. The inner vertical plate of the horizontal ramus is continued further 

 back than in existing Kangaroos and Wallabies, forming an inner wall (ib. fig. 8, f), 

 with a definite and sharp margin, beneath the base of the coronoid process ; and fi om 

 the point where this hind margin of the inner mandibular plate is continued upward 

 into the coronoid, a low ridge extends on the side of the plate next the large cavity of 

 the ascending ramus forward and downward to the entry of the dental canal. This 

 ridge (ib. fig. 14, g) divides the cavity into an upper (/) and lower (a) compartment. 

 The structure is repeated, as will be seen, in the specimen next to be described. 



The curve and direction of so much of the diastemal ridge (ib. fig. 3, I) as is here 

 preserved resemble rather that of Macropus and Halmaturus than of Sthenurus ; but 

 the less mutilated specimen (ib. figs. 7 & 8) shows the toothless tract (I, s') to be rela- 

 tively shorter as compared with the molar series than in either of those genera of 

 existing Kangaroos. 



This specimen likewise forms part of the series of fossils from the river-beds at Eton 

 Vale, Darling Downs, presented by Sir Daniel Cooper, Bart., to the British Museum. 



The molar series (ib. figs. 7, 8, 9, p s-Wi 3) agrees in extent and in the proportions of 

 the five teeth with the type specimen, but the fossil is from a less aged individual. The 

 hind angle of the sectorial crown of p 3 (fig. 9) is made obtuse and polished by wear. 

 The dentine exposed on both lobes of m 2 is transversely linear, with a slight forward 

 production in both links (r and s). In m 3 a speck of dentine appears on the inner 

 angle of the front lobe (a) : the enamelled ridges of this and the hind lobe show the 

 oblique polished tract at their hinder surface. The characteristic proportions of both 



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