DIPROTODON. 
285 
lower jaw of the Kangaroo, where the band forms a still more 
prominent ridge on the fore part of the tooth, and is almost 
always wanting on the hinder part, though it may be seen in 
some species, as for instance in the fossil species to which 
Professor Owen 1ms given the name Macropus atlas. The 
length of the fourth molar tooth, in one fragment of a lower 
jaw is l n ^ inch, and its width l^t- inch; the length of the 
fifth molar is 1J inch, and its width \\ inch. The lower jaw 
is remarkable for the great extent and depth of the syinphv- 
sial portion, (its vortical diameter, anterior to the molar series, 
is 1 inches,) a structure which has relation to the great develop¬ 
ment and deep implantation of the incisors, and which leaves 
a long toothless interval between these teeth and the molars. 
The angle of the jaw is distinctly bent inwards, and the lower 
edge of the ramus at this part presents a broad flattened sur¬ 
face—characters in which we perceive a manifestation of the 
Marsupial affinities of the animal, and when we find the 
molar teeth approximating very’ closely in their structure to 
those of the Kangaroos, accompanied by dental formula of 
another herbivorous Marsupial division, the Wombats, where 
the incisors, as in Diprotodon, are but partially covered by 
enamel, we have strong grounds for regarding the Diprotodon 
as a Marsupial animal. But these are not the only grounds 
adduced by Professor Owen, in proof that the animal under 
consideration belonged to the Marsupialia; numerous frag¬ 
ments of other parts of the skeleton found together with the 
parts of the jaws noticed, which at the same time, from their 
correspondence in mineral condition, and in relative propor¬ 
tions with die jaws, it is highly probable belonged to the some 
animal, all more or less bear out the conclusion. I shall 
here only notice two of the most complete hones wliich were 
found in die bed of the Condamine River, with the portions 
ol the lower jaw. The first of these is the body of n dorsal 
