PROFESSOR OWEN ON MACROPUS. 425 
(fig. 6: in this figure the grinding-surface of d4, pushed out of line in the lower 
jaw, is added in front of the figure of the tooth so displaced). 
The first, perhaps chief, difference between Macropus rufus, Dsm., and M. major, 
Shaw, is the smaller relative extent of the crown of the upper and outer incisor, 3 7’, 
which shows only one shallow vertical impression along the middle of the outer 
surface. On this mainly would rest its claim to a subgeneric distinction, such as 
Gould has indicated by the term Osphranter; but the incisor-character is not repeated 
in other species of Osphranter (M. robustus, M. antilopinus, e. g.). The above dental 
distinction of M. rufus, however, is associated with several cranial ones. In the 
skull of a full-sized male, with teeth more worn than in that of a MW. major com- 
pared with it, the temporal ridges have not met along the sagittal suture, but 
are separated by a tract half an inch in breadth, along the middle of which the 
sagittal suture persists. The anterior angles of the parietals give better indications of 
postorbital tubercles. These, however, are not more shown in WM. rufus than in WV. 
major. In a skull of the WM. (Osphranter) robustus compared, which retains the 
premolar (p 3) with four fully developed molars behind, the sagittal crest is better 
marked than in W. major and M. rufus, in which that premolar is shed. 
The Great Red Kangaroo is one of the largest” of the tribe; and the skull here 
described equals in length that of the largest in the Table of Measurements of M/. 
major*®, yet it indicates a less powerful animal. The paroccipitals are more slender. 
The zygomatic arches have less span and depth; the masseteric process is much 
shorter; the ridge above the fore part of its base is due to the malar more than to the 
maxillary. The mandible is more slender; the coronoid process is shorter and 
narrower from before backward; the depth of the ramus behind the molar series is 
notably less in MW. rufus; yet the last molar, with the same fore-and-aft extent as in 
M. major, is broader. 
The basioccipital ridge in M. rufus is sharper. The upper border of the foramen 
magnum is notched. ‘The condyles are narrower, and the ectocondylar grooves deeper 
and wider. ‘The superoccipital is less elevated and more truncate atop; the base of 
the occiput is narrower. ‘The facial plate of the lacrymal is broader, and the lower 
and larger foramen is more external. The antorbital foramen is further from the 
orbit. The premolar part of the skull is shorter and deeper; the maxillary out- 
swelling is less definite. The facial plate of the premaxillary is broader antero- 
posteriorly. The incisive foramina are longer and further from the third incisors. 
The postpalatal apertures are larger, especially the right one; but this may be a 
variety: the bony palate behind them shows more and larger irregular perforations, 
the hamular process of the pterygoid is less defined, than in Macropus major. 
Such are the chief differences observable in the skulls of M. rufus and M. major; and 
they are here noted as guides in the comparison of fossil cranial parts of Macropodide. 
' As indicated by Waterhouse, op. cit. p. 107, and illustrated in his plate v. fig. 3. * Ib. p. 104. Palby 
VOL. 1x.—pPart vit. March, 1876 3M 
