410 



ascending ramus appears to be the same in the present fossil as in the largest existing 

 species of Kangaroo. The inner postaiveolar border is smoothly rounded, and forms 

 no angle indicative of a postaiveolar process. 



The molars in the fossil under description are more worn than in the Macropus major 

 compared, with a similarly reduced series of teeth. In d i (Plate LXXXII. fig. 14) 

 the exposed tract of dentine is continuous, the mid link crossing the valley being worn 

 through. The prebasal ridge is indicated only by the internal notch; the basal remnant 

 of the crown is supported by fangs, which are partially exposed by absorption of the 

 alveolus, and the crown overhangs the beginning of the diastema, indicative of the im- 

 pending fall of the tooth (ib. fig. 13, dt); whence I infer that the molar dentition of 

 Macropus Titan would be reduced in advanced age, like that in Macropus major, by the 

 loss of d i, and perhaps ultimately of m i*. 



The pattern of the working-surface of the succeeding molars closely accords with that 

 in Macropus proper. The prebasal ridge is considerable, both longitudinally and trans- 

 versely: the fore link is well marked ; it joins the front lobe external to the mid line, 

 Leaving a fossa on each side. The contrast with the rudiment of this link in Sthenurus 

 Atlas (ib. figs. 8 & 9) is considerable, as is that also in the development of the mid link 

 and the breadth of the anterior margin of the prebasal ridge. 



The antero-posterior breadth of the transverse ridges is greater in Macropus Titan 

 than in Sthenurus Atlas, especially at their outer sides (comp. figs 13 & 5); the 

 longitudinal extent of the crown is relatively greater as compared with the transverse 

 diameter in Macropus Titan. 



In the next illustration of the mandibular characters of Macropus Titan, so much as 

 is preserved of the two rami shows the angle at which they meet to unite at the sym- 

 physis (Plate LXXXVI. fig. 9). It also shows that the comparatively loose union of the 

 symphysis had permitted the right ramus to glide a little forward from the left one 

 before they were fixed in position by the petrified matrix ; but this correspondence with the 

 large living Kangaroos is more decidedly shown in the subject of fig. 11, Plate LXXXVI. 

 The right ramus of fig. 9 includes the last four molars, d i, mi, m-2, wis, and a part of 

 the premolar, p a (this tooth, like the crown of m i, has suffered more from fracture 

 than from masticatory action). The left ramus includes the last three molars and the 

 hind half of the crown of d *. The present fossil was obtained by Henry Hughes, Esq., 

 in the freshwater deposits of Queensland, and is now in the Museum of the Natural- 

 History Society of Worcester. 



In a fossil with three molar teeth (d 4, m i, and m 2), and the formative cavity of m 

 these teeth are somewhat inferior in size to their homologues in fig. 13, Plate LXXXII., 

 and probably indicate that they come from the female of Macropus Titan. The sub- 

 ject of figs. 12 & 13, Plate LXXXIIL, is the original specimen in the Museum of the 

 Royal College of Surgeons, No. 1512 f, which first afforded the characters of the 



* Since this passage was penned I have received from my friend Dr. Benitext, F.L.S., evidence of the fact, 

 t Catalogue, ut supra, p. 325. 



