PROFESSOR OWEN ON THE FOSSIL MAMMALS OF AUSTRALIA. 
263 
antero-posterior extent of m i is a trifle more in the fossil. We may infer from the 
superior size, both absolute and relative, of the premolar in Phascolagus altus that the 
permanent molar dentition would be represented for a longer period of life by the five 
teeth, p 3, di, m 1 , m 2, and m 3 , than in the existing Great Kangaroo ( Macropus 
major). 
The specimen above described, with the rest of Sir Thomas L. Mitchell’s first 
collection of cave-fossils from Wellington Valley, is in the Museum of the Geological 
Society of London. I am indebted to the President and Council for the opportunity of 
giving new and better figures of the type of Phascolagus altus than the original ones in 
the £ Appendix ’ of the above-cited work. 
In the collection of fossils from the freshwater deposits of Queensland, lately 
received from Dr. George Bennett, F.L.S., of Sydney, New South Wales, there are 
instructive evidences of Phascolagus altus adding to our knowledge of its cranial and 
dental characters. The specimen No. 38752, Register of Fossils, British Museum, is 
part of a right maxillary of a young animal with the dentition in nearly the same state 
as the subject of figs. 1 & 2, Plate XXII. The germ of the premolar seems rather less 
than in that type specimen ; but the hind angle was broken off in the work of exposure, 
which the state of petrifaction of the lacustrine fossils made more difficult than in the 
Cave specimen. The fore link is a little more marked in m 2 than in the type speci- 
men, but the agreement in other characters is sufficiently close to determine the species 
and subgenus as above defined. 
The next Bennettian specimen is from a somewhat older individual of Phascolagus 
altus ; it is a portion of the right maxilla with d 4, m 1, and m 2 in place ; these three 
molars occupy the same extent as that in the skull of Boriogale magnus , the upper 
molars of which are figured in Plate XX. fig. 12 — an extent about 1 line short of that 
in Macropus rufus (Plate XXIII. fig. 1), and about 1 line more than that in Osphranter 
robustus (fig. 3, Plate XXI.). We have here, therefore, plainly demonstrated, the repre- 
sentative of a Kangaroo about the size of the largest now living in Australia. Inde- 
pendently of the premolar character shown in the previous specimens, the present fossil 
could not be referred to Macropus major. The antorbital foramen is too remote from 
the orbit and from the ridged beginning of the masseteric process, which also is more 
directly continued from the fore border of the orbit than it is in Macropus major. 
The foramen in question is 7 lines in advance of the nearest part of the masseteric ridge 
in the fossil ; it is 3^ lines in advance of that ridge in Macropus major. 
In the position of the antorbital foramen the fossil more resembles Osphranter 
robustus , in which, however, the foramen is about a line further in advance of the 
masseteric ridge ; this, in its prominence, sharpness, and the depression anterior to it, 
resembles more than does Macropus major the fossil fragment compared. Boriogale 
more closely repeats the above-defined cranial character in the fossil. But Phascolagus 
has the palate entire, where Boriogale shows the large vacuity (Plate XX. fig. 12) 
common to it with the type species of Halmaturus , F. Cuv. In the molars of Phasco- 
2 m 2 
