122 THE ORDER DINOCERATA. 
breadth, were followed by six small molar teeth. Each of these were 
composed of two well developed, nearly straight, transverse ridges, 
which joined at the inner border of the tooth, and diverged as they 
Skull of Dinoceras mirabilis, copied from Professor Marsh’s figure, and kindly lent 
by the Proprietors of “ Nature.” 
ran outwards, so forming a simple >-shaped pattern, that continued 
well marked till the tooth was much worn. The posterior of the 
two ridges was quite transverse, and the anterior was slightly concave 
backwards, and ran obliquely forwards and outwards. These teeth 
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diminished in size from before backwards gradually, and there were 
no intervals between them. All that I can find about the lower jaw 
is that it was slender, and its tusks small. 
The orbit was not separated from the temporal fossa, which latter 
was large, extending up the outer side of the lateral parieto-occipital 
crest. The malar completed the anterior portion of the zygomatic 
arch; the lachrymal was large, forming the anterior border of the 
orbit; a large oval foramen perforated its facial surface. The squa- 
mosal sent down a large post-glenoid process. The nasals were massive, 
and greatly prolonged forwards, at the tip carrying the anterior 
horn-cores; they also sent slight processes up the inner faces of the 
maxillary horn-cores. The premaxillaries were peculiar in that they 
almost enclosed the anterior nares; they united posteriorly with the 
maxillaries just in front of the canines, and then divided into two 
branches, one of which, the lower, corresponding to the premaxillary 
of the Rhinoceros, ran forwards free; the other, closely uniting with 
