PROFESSOR OWEN ON THE FOSSIL MAMMALS OF AUSTRALIA. 
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second molar ( d 4), the junction taking place at the mid interval between the right and 
left premolars (p 3) ; the posterior ridge similarly bridges the palate between the alveoli, 
right and left, of m 2 & m 3, fig. 4, Plate LXXIX. 
On the working-surface of the crown of p 3 the transverse ridges of enamel along the 
tract occupying the fore and inner part of that surface appear. This tooth is broadest 
behind ; it is supported by three stout fangs ; the foremost diverges from the hind pair 
as it ascends into the substance of the jaw, where two thirds of an inch of it is exposed ; 
it is thick, and the cemental coat is longitudinally and irregularly striate. 
At the back part of m 1 two of the deep vertical notches (ib. fig. 9, h) and the intervening 
strong ridge of enamel (ib. g ) are conspicuous. The fore link ( 5 ) and the accessory link 
to its inner side, also the mid link and the accessory ridges on the surfaces of the lobes 
internal to it, are shown. The prebasal ridge (f), with the fore link (s) of the last molar 
(m 3, fig. 4), has been broken off and slightly displaced from the rest of that tooth, in 
which the indents and ridges on the hind surface are well displayed. At every part of 
the worn and fractured surface of this molar series the stalactitic-like complexity of the 
thick and hard enamel is exemplified. The figures being of the natural size preclude 
the need of giving dimensions of the several teeth. 
In the smaller portion of maxilla and molar series (Plate LXXIX. figs. 5, 6, 7) the 
coronal modifications of m 1 and m 2 are instructively displayed. Viewing the working- 
surface from above, the postbasal ridge seems to be represented by a short bar of enamel 
(figs. 7 & 9, g) supporting the bases of the narrow but strongly developed pyramidal 
ridges (ib. h), sending their apices to the working-surface of the hind lobe ; but the 
basal bar does not project like a true basal ridge from the hinder convex surface of the 
crown (fig. 9). 
The correspondence of the complex pattern of the crown of the lower with the upper 
molars, combined with the usual modifications of greater length of the prebasal ridge, is 
patent in the subject of figs. 1 & 2, Plate LXXX. In this fossil the last molar (m 3) 
had but recently risen into place, and the antecedent one (m 2 ) showed slight traces of 
abrasion. In d 4 the front lobe (a) is narrower than the hind one (b) ; these proportions 
are reversed, but in a minor degree, in the last molar (m 3 ). The fore (s) and mid ( r ) 
links are well defined. Deep clefts on the back of the hind lobe mark out the vertical 
ridges of enamel, of which one is shown at g, fig. 2. The base of the coronoid process 
(fig. 1, g) advances forward a little beyond m 3. 
The characters of the lower molars of Procoptodon Goliah are further exemplified in 
a smaller fragment of a large, apparently male, animal, with the last two molars showing 
a greater degree of wear. This specimen (Plate LXXX. figs. 3 & 4, Plate LXXIX. 
fig. 8), now in the Museum of Natural History of Sydney, New South Wales, has been 
made known to me by a good plaster cast. The penultimate molar ( m 2 ) is slightly 
worn, the last ( m 3) in a less degree ; but both had been in use and indicate a full-grown 
though not old individual. 
The prebasal ridge (ib. ib. fig. 8,/*), commencing externally at the outer and fore 
5 0 2 
