405 



been. This prepalatal groove is not shown in Macropus major, Macropus rufus, or 

 Osphranter robustus. 



The maxillary bone extends for 10 lines behind the last molar, on the level of the 

 alveolar openings, and is there impressed by the shallow groove leading to the foramen 

 and canal between the back part of the maxillary and the pterygoid process of the 

 alisphenoid. The figures (ib. figs. 15-18) being of the natural size preclude the need 

 of verbally noting admeasurements. 



The side view of a corresponding part of the upper jaw of a large male Macropus 

 rufus, at the same stage of dentition as in the present fossil, is given in Plate LXXXI1I. 

 fig. 1 ; it is from one killed by Mr. Gould, and was the largest Kangaroo which he 

 saw in Australia. 



In reference to the constancy in size and other characters of Macropus Titan, I was 

 fortunate in finding a second specimen from an adult of this fine extinct Kangaroo in 

 the Geological Museum of the University of Oxford, which Professor Phillips liberally 

 transmitted to me for comparison and delineation. It was accompanied by an almost 

 entire lower jaw of the same species, at the same phase of dentition, and apparently of 

 the same individual. Both had been obtained by Dr. Nicholson, of Sydney, New South 

 Wales (now Sir Charles Nicholson, Bart.), from the freshwater deposits of Queensland. 



The subject of figs. 10, 11, & 12, Plate LXXXIL, is part of the left upper jaw with the 

 last four molars (d i-m z) in place ; d z and p z have been shed and their sockets 

 obliterated. The crowns of the remaining teeth show different degrees of abrasion, 

 the summits of the last molar being slightly worn, not so as to expose the dentine. 

 This specimen, therefore, bespeaks a fully mature but not aged animal. 



The bone includes the base of the anterior pier of the zygomatic arch (from which the 

 dependent process has been broken away), part of the floor of the orbit with the orbital 

 aperture of the antorbital canal, and a considerable extent of the bony palate (showing 

 the same imperforate structure as in the preceding specimens of Macropus Titan). 



The pier of the zygoma extends obliquely from the under and fore part of the orbit 

 downward and backward, the hind border being on the vertical parallel of the middle of 

 the last molar. The ridge from the outer side of the masseteric process subsides, as it 

 rises toward the orbit, sooner than in Macropus major or Macropus laniger. As in the 

 last described specimen, the anterior outlet of the suborbital canal is relatively further 

 in advance of the orbit than in Macropus major, being an inch from that part and on a 

 vertical parallel with the diastema in advance of the front molar (d i) ; in Macropus 

 major it is above the interval between di and m i, and opens only 4^ lines in advance 

 of the orbit. In Osphranter robustus, Gd., the antorbital foramen is 10 lines in advance 

 of the nearest part of the orbital margin, and is on the vertical parallel of d 4. It thus 

 more nearly resembles Macropus Titan than does Macropus major; but the larger 

 extinct Kangaroo differs from both the large existing species in the following structure, 

 which I now have ground for regarding as constant. There is, as observed in former 

 fossils of Macropus Titan, a foramen (a) 3 lines behind the antorbital one (21), fig. 10; it 



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