400 



genus, with the dentition, as to the formula and fundamental pattern of the molars, oi 

 the bilophodont Macropodida?, the extremest deviation from the characters of the existing 

 subgenera which the fossil remains of the family have yet exhibited. 



I infer from the proportions and shape of the mandible that the rest of the skeleton 

 may have presented a more robust character, with thicker and shorter extremities and 

 with less inequality between the fore and hind pairs of limbs than in the living Kanga- 

 roos. Of these, as before remarked, Procoptodon Pusio must have exceeded in bulk 

 the largest known. This excess is greater in Procoptodon Kapha. But the following 

 fossils show that their generic modifications have been exemplified on a more gigantic 

 scale. 



§ 24. Procoptodon Goliah, Ow. — The present extinct species of Macropodida? was 

 first indicated by a fragment of a maxillary bone with three molars, transmitted to 

 me by Sir Thomas L. Mitchell, C.B., in 1844. 



As the two smallest of these measured rather more than one inch and a half in the 

 antero-posterior direction, and the least transverse diameter was 7^ lines, I provisionally 

 assigned to the species the name " Macropus Goliah" and communicated my brief notes 

 on the fossil to George R. Waterhouse, Esq., at that time engaged in his excellent work, 

 'The Natural History of the Mammalia'*. The type-specimen is figured in Plate 

 XCIV. fig. 1. 



My hopes of further elucidating the singular extinct gigantic Kangaroo so indicated 

 have been, through the kindness of friends and correspondents in Australia, abundantly 

 fulfilled. The grounds of the formation of a distinct genus of Macropodidce, of which the 

 " Goliah" is the type, are given in the subsection (§ 21) descriptive of the smaller species, 

 Procoptodon Pusio. As in that species, the two lobes of the molar (Plate XCIV. fig. 1, 

 m i, 2, 3) have a more regular elliptic basal section than in the foregoing genera ; their outer 

 and inner ends are more convex or bulging ; they are not separated by so deep a valley, 

 and this lodges a greater proportion of hard enamel in the form of irregular subundu- 

 late ridges, affecting mostly the longitudinal direction, the chief of which may, however, 

 be homologized with the mid link of more normal Macropods. The fore surface of the 

 front lobe and the hind surface of the back lobe are similarly sculptured by irregular 

 ridges, of which two are more conspicuous than the rest at the back of the molar, within 

 a depressed area defined by the abrupt sharp margins, inflected upon that surface of the 

 outer and inner convex ends of the hind lobe. The unworn summits of both lobes 

 are less regularly or extensively transverse than in ordinary Kangaroos, the inner angle 

 curved backward. There is a low and short prebasal ridge, but no such definite pro- 

 duction from the back part of the hind lobe. 



The fore pier of the zygoma, at least so much of the hind part thereof as was preserved 

 in the present fragment, stands out opposite the antepenultimate tooth (in 1), and its hind 

 curve subsides before reaching the last molar. The narrow plate extending from the 

 palatal wall of the alveoli terminates in a smooth and seemingly natural border. But 



* Part 2, Macropodidce, 8vo, 1845, " Macropvs Goliah, Ow.," p. 59. 



