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being led astray by the close general resemblance of the upper molars of Nototherium 

 with those of Diprotodon. The present fragment being from a young specimen, the 

 dental lobes show well their vertical curve concave forward, and the transverse curve of 

 the edge of the wedge concave backward. I availed myself of this fragment to expose 

 the front roots of the anterior molar and the hind root of the posterior molar ; but these, 

 with other dental characters, will be noted in the section on the teeth of Nototherium- 

 The present specimen afforded the subj ect of fig. 8 in Plate XLIII. : it shows a part of 

 the convex roof of the alveolar tract which projects into the orbito-temporal vacuity, 

 and the contiguous groove for the superior maxillary nerves and vessels. 



The second cranial specimen is a larger proportion of the left maxilla with three 

 molars in situ (d *, m i, m 2), part of the socket of the first (d 3), and the base of the crown 

 of the last (m 3) rooted in its socket. 



A portion of the bony palate extends with a slight upward curve, inward, from the 

 sides of the sockets of d », d 4, and more distinctly inward from those of m 1 and m 2. A 

 breadth of 1 inch 6 lines is preserved (opposite d 4) : the fracture reduces the breadth to 

 6 lines as it extends backward to the alveolus of m 3. So much as is preserved of the 

 bony palate confirms the inference of the entireness of the bony roof of the mouth 

 deducible from the cut and photograph of the entire cranium, as far back at least as the 

 sockets of m 3, right and left. The hind part of the origin of the zygomatic process of 

 the maxillary is here at the vertical parallel of the interval between m 1 and m 2, con- 

 sequently rather further back than in the former fragment. The worn surfaces of m 1 

 and m 2 show the present to have come from an older individual, as will be subsequently ' 

 pointed out in detail. An extent of 3 inches of the massive maxillary pier, as its origin 

 extends from behind obliquely upward and forward, is here preserved ; the thickness of 

 the process is 1 inch 3 lines. The height of the alveolar process or tract at the last two 

 molars is 2 inches 9 lines. The transversely convex or arched roof of these sockets is, 

 relatively, less broad and prominent than in the Wombat ; its extent and proportions 

 resemble more the corresponding part in the Kangaroo, conformably with the common 

 character of three-rooted teeth of limited growth, which contrasts with that of the large 

 undivided bases of the corresponding molars in Phascolomys, retaining their formative 

 matrices, and making a proportional prominence outside the " superior maxillary chan- 

 nel." This channel in Nototherium describes a curve convex outward as it courses 

 forward to perforate the antorbital part of the maxillary and emerge upon the outer 

 surface of that bone (as the 'antorbital foramen,' 21, fig. 1, Plate XXXVII.). 



The third portion of the skull of Nototherium includes part of the right maxillary 

 with three molars (d 4, m 1, m 2) in situ, and part of the right palatine bone (Plate XLIII. 

 figs. 6 & 7). The teeth are more worn than in the preceding specimen : the fossil is part 

 of an aged individual ; the teeth, moreover, show a superiority of size compared with those 

 of the last described fragment, answering to the difference one sees between the molars 

 of the full-grown male and female Kangaroos. 



The hind surface of the maxillary pier of the zygomatic arch here lies vertically 



21 



