[extract from p. 134, Editor] The skull [of Macropus isabellinus, Gould] differs widely from that of M. rufus; in this species the facial region is proportionately greater than in any other kangaroo, and the nasals are correspondingly long and narrow. In M. isabellinus, as already mentioned, the facial region is the shortest of all the kangaroos, and is, in this respect, nearest allied to M. robustus, in which also the nasals are short and broad.
As M. isabellinus was known only from a skin, and M. magnus, Owen, from a skull, there was, as suggested by Thomas, a possibility that the two were identical. The study of a skull of the former shows that the species are quite distinct. In M. magnus the opening of the lacrymal canal is entirely in the lacrymal bone, the palatal foramina are very long, extending some way into the maxilla, and the posterior palate is very incomplete.