102 
Records of the Geological Survey of India. 
[vol IX. 
1 now come to the premolar teeth of my specimen, hitherto unknown, and which are of 
a most abnormal and interesting character. These teeth vastly exceed in size the true molars, 
a character which is, I believe, unknown among other mammals ; they are placed in direct contact 
with the molar series, and have a general resemblance in form to those of Hippopotamus wadi 
Merycopotamus ; eaioh is inserted into the jaw by two fangs; the penultimate premolar does not 
present any facet of pressure on its anterior surface, and was therefore probably separated by 
a diastema from the preceding tooth. 
The ultimate premolar has a nearly square base, from which rises an oblique compressed 
cone, the summit being directed backwards and placed a little in advance of the hindmost 
border of the crown ; the anterior face of the cone projects into a sharp sinuous ridge running 
from summit nearly to base, expanding below into a cingulum, which occupies the greater part 
of the anterior base ; the cingulum slopes from the ridge to the antero-external angle. A small 
tubercle occurs between the summit of the cone and the posterior border ; this tubercle forms the 
summit of another cingulum occupying the posterior surface ; the posterior cingulum slopes towards 
the base of the crown on each side from this central point; the outer extremity of the cingulum 
forming a very marked ledge at the postero-external angle of the crown; a rounded notch occupies 
each side of the crown between the roots of the fang. The inner surface of the tooth is 
nearly vertical, the outer sloping. 
The enamel is arranged in irregular branching ridges radiating from the summit to the 
periphery of the base; these ridges are again marked by fine parallel transverse stria;. 
The summit of the crown is worn obliquely, the face directed upwards and backwards; 
the worn surface present two facets, and is of an irregular oval shape, the longer diameter placed 
antero-posteriorly. 
The penultimate premolar differs from the other in being rather smaller in the base 
of the crown presenting a somewhat triangular cross-section, and in the summit of the coue 
being more directly over the centre of the crown. A more prominent ridge from this summit 
runs along the centre of both anterior and posterior surfaces; the posterior cingulum is also 
rather more prominent. 
The dimensions of the specimen are as follows, in inches a 
Length of two molars 
Ditto 2nd molar ... 
Width of ditto ditto 
Height of ditto ditto 
Length of ultimate premolar 
Width of ditto ... 
Height of ditto ... 
Length of penultimate premolar... 
Width of ditto ... 
Height of ditto ... 
Depth of jaw at ultimate premolar 
Length of the penultimate molar of Falconer’s specimen ... 
Tlie general form of the premolars resembles those of Hippopotamus : the cingulum, however, 
is confined to the fore and aft surfaces only. In the position of the cingulum, and in the straight¬ 
ness of the inner wall of the premolars, the specimen approaches the premolars of Mery copot amus. 
As stated hy Falconer, the molars can only be compared with those of Hippopotamus and 
its allies; the position of the four cones at the corners, and the absence of the trefoil-shaped 
surface of wear, sufficiently distinguishes the molars from those of Hippopotamus. From Sus 
they are distinguished by the slight degree of obliquity of the worn surface, and from the crown 
surface not being a collection of semi-distinct tubercles, but divided into four distinct simple 
cones. The cruciform valley is a character common to this genus and Sus. 
id tenths:— 
2*50 
1*45 
1'30 
•80 
2*15 
2-10 
1'80 
2*05 
1-80 
1*65 
3*10 
1*40 
