AMPHITHERIUM. 5I 
The exposed surface of the coronoid process is slightly 
convex. The surface of the ascending ramus of the jaw 
is entire above the angle, whence we may conclude that, if 
the process from the latter part had been continued directly 
backwards, it would also have been entire; but the extre- 
mity of the angular process is broken off, proving it to have 
originally inclined inwards, or towards the observer: as, 
however, the greater part of the angle is entire, it could 
not have been inflected to the same extent as in the Didel- 
phys, Dasyurus, or the Phascolotherium next to be describ- 
ed. A groove is extended from the lower end of the 
articular condyle forward to the orifice of the canal for the 
dental artery, where it divides; the upper branch ter- 
minates in the dental orifice, the lower and larger division 
is continued forward near the lower margin of the jaw, 
gradually contracting and disappearmg half way towards 
the symphysis: this smooth vascular groove has as little 
resemblance to an articular fissure as in the former speci- 
men. ‘There is a broader and shorter groove in the corres- 
ponding part of the jaw of the Myrmecobius; and a 
narrower groove in that of the Wombat. The alveolar 
wall of the posterior grinders makes a convex projection, 
characteristic of the inner surface of the ramus of the 
lower jaw. The posterior grinder in the present jaw is 
fortunately more complete than in the first example, and 
shows a small, middle, internal cusp, with part of a large 
external cusp, both projecting from the crown of the tooth 
in nearly the same transverse line. The enamel covering 
the internal cusp, which is vertically fractured, is beautifully 
distinct from the ivory, and considerably thicker in propor- 
tion to the size of the tooth than is the enamel or its 
analogue in the teeth of any species of reptile, recent or - 
fossil. The six molars anterior to the one in place, are 
E 2 
