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opposite border, and encroaches upon the anterior part of the shaft: it is relatively lower, and swells out more abruptly than in the femur No. 1489; there is no trace of a third trochanter. The post-trochanterian depression resembles that in No. 1489. The shaft of the present fossil is more flattened anteriorly than in No. 1503: this antero-posterior compression gives it the same resemblance to the femur of the Mastodon and Elephant as has been pointed out in the description of No. 1489. The large extinct phyllophagous Edentata manifest this character in an exaggerated degree: the Rhinoceros is the only genus amongst the ordinary Pachyderms in which the femur is flattened as in the great extinct Australian quadrupeds, but the third trochanter effectually distinguishes that bone in the Rhinoceros. It is evident, from the differences above detailed between the present femur and No. 1503, that they belong to distinct though perhaps to nearly allied species. The form of the transverse section of the shaft is more regularly elliptical, and the anterior surface more flattened, in the present fragment than in No. 1503, which, from its closer resemblance with No. 1489, might well have belonged to a young individual of the same species."
"The right ramus, with the symphysis of the lower jaw, of the Nototherium inerme, Owen, a quadruped apparently manifesting another pachydermal modification of the marsupial type.
"The dentition in the present jaw consists of molar teeth exclusively, four in number, which increase in size as they approach the posterior part of the series: a small portion of the anterior end of the symphysis is broken away, but there is no trace there of the socket of any tooth, and it is too contracted to have supported any tusk or defensive incisor. The length of the jaw is eleven inches: the molar series, which commences one inch in advance of the posterior border of the symphysis, is six inches in extent; each tooth is implanted by two strong and long conical fangs, the hindermost being the largest, and both being longitudinally grooved upon the side turned to each other. The first tooth is wanting, and the crowns of the rest are broken away: the base of the third remains, which gives an indication of a middle transverse valley, which most probably separated two transverse eminences. This jaw resembles that of the proboscidian Pachyderms in the shortness of the horizontal ramus; and of the Elephant more particularly in the rounding off of the angle, and in the convex curvature of the lower border of the jaw from the condyle to the symphysis, and also in the smaller vertical diameter of the symphysis, and the more pointed form of that part. It resembles the jaw of the elephant in the form, extent, and position of the base of the coronoid process; but it differs from the Elephant in the concavity on the inner side of the posterior half of the ramus of the jaw, which is formed by an inward inflection of the angle: this concavity extends forwards beneath the sockets of the last two molar teeth. It differs from the Elephant in the greater flatness of the outer part of the angle of the jaw, in which respect it more resembles the Mastodon. In the extent of the angle of the jaw it is intermediate between the Mastodon and Elephant. It differs from both in the inward bending of that angle, which is remarkable for the great longitudinal extent along which the inflection takes place: most of the inflected angle has been broken away, but enough remains to demonstrate a most instructive and interesting correspondence between the present fossil and the characteristically modified lower jaw in the marsupial animals. In pursuing the comparison of the Australian pachydermal fossil with the Mastodon and Elephant, we may next observe, that the alveolar process on the inner side of the base of the coronoid, behind the last molar, is as well developed as in the Mastodon; a similar angular production of this part exists in the Wombat and Kangaroo. The vertical extent of the outer concavity of the coronoid process is greater in the Australian fossil than in the jaw of the Mastodon, and is less clearly defined below, in which respect the Notothere resembles more the Elephant. The dental canal commences by a foramen penetrating the ridge which leads from the condyle to the post-molar process, and apparently just below the condyle, as in the Elephant, but it is relatively much smaller: it does not communicate with any canal leading to the outer surface of the ascending ramus, as in the Wombat and Kangaroo; but this external opening is not present in all Marsupialia.
* Votoc the south, 0-npiov beatt.
"The anterior outlet of the dental canal is smaller than in the Mastodon, and more anterior in position, and so far resembles the Elephant. The number, and apparently the form of the teeth, approximate the Australian Pachyderm more closely to the Mastodon than to the Elephant; but the equal size of the last and penultimate teeth, which had the same number of divisions of the crown, are points in which the Nototherium still more nearly resembled the Diprotodon, the Tapir, and Kangaroo.
"In the general shape of the jaw, however, the Xototherium differs Avidely from all existing Marsupials, and all known ordinary Pachyderms, and in the chief of these differences it resembles the lower jaw
of the Proboscidians. It resembles these, however, in common with the Wombat, in the forward slope and curvature of the posterior margin of the ascending ramus extending from the condyle to the angle, in the inward production of the post-molar process, in the position of the base of the coronoid process, exterior to the hinder molar, in the thickness of the horizontal ramus as compared with its length, and the convexity of its outer surface; and it also resembles the Proboscidians, in common with the Kangaroo, in the small number of the grinding teeth.
"From the lower jaw of the Kangaroo and Wombat that of the Nototherium differs in the absence of the deep excavation on the outer side of the ascending ramus, which, in those Marsupials, leads to a perforation in the base of that part of the jaw, and it also differs in the inferior depth of the inner concavity and the inferior extent of the inward production of the angle of the jaw; besides the more important difference in the absence of the large incisor tooth. From the jaw of the Diprotodon, No. 1460., the present fossil differs in the much smaller vertical extent of the symphysis, and in the convexity of the jaw at its outer and anterior part, and more particularly in the absence of the incisive tusk and its socket; but it must have closely resembled the Diprotodon in the general form and proportions of the molar teeth.
"From the alluvial or newer tertiary deposits in the bed of the Condamine River, west of Moreton Bay, Australia."
"The astragalus of a large marsupial quadruped, probably the Nototherium inerme. The peculiarities of this astragalus will be obvious to the comparative anatomist from the following description. It is a broad, subdepressed, and subtriangular bone, the
angles being rounded off, especially the anterior one; the upper or tibial surface is quadrate, concave from side to side, in a less degree convex from before backward: a ridge extending in this direction divides the tibial from the fibular surface, which slopes outwards, at a very open angle, and maintains a nearly horizontal aspect, presenting an oblong trochlea for the support of the fibula, shallower, and one-third smaller than that for the tibia. The tibial articular surface is not continued upon the inner side of the astragalus, but its anterior and internal angle, which becomes convex in every direction, is directly continued into the anterior scaphoidal convexity, which sweeps round a deep and rough depression, dividing the outer and anterior part of the tibial trochlea from the corresponding half of the scaphoidal convexity; this has the greatest vertical extent at its inner part, where it is separated by a narrow rough transverse channel from the part which rested upon the os calcis. The calcaneal surface is single, and covers almost the whole of the under part of the astragalus: the greatest proportion of it is flat and reniform; an angular tuberosity or process being continued from the concave margin, where the pelvis of the kidney, to pursue the comparison, would be situated. This process must be received into a corresponding depression at the outer part of the articular surface upon the calcaneum. On the inner margin of the flat calcaneal surface opposite the tuberosity, a small triangular flattened surface is continued upwards upon the inner and posterior side of the astragalus, and nearly touches the inner and posterior angle of the tibial trochlea.
"The length of this fossil astragalus is four inches eight lines; its breadth is three inches five lines; its depth (at the base of the scaphoidal convexity) is two inches and a half. We look in vain amongst the