MOLAE TEETH AND OTHEE EEMAINS OE MAMMALIA. 
61 
The discovery of that specimen fully carries out Ealconer's idea of the generic 
distinctness of the form^ although it seems to have been generally neglected by 
subsequent writers. 
Tetraoonodon magnum, Falconer. Plate 10. 
The unique specimen of the greater part of the right ramus of the mandible 
of this species, of which three views are given in the accompanying plate, has 
already been shortly described in the “ Eecords of the Geological Survey of India” 
{vol. JX, p. 101), but is now for the first time figured; the present description is 
mainly copied from the above notice. 
The specimen was discovered by Mr. Theobald in the Upper Siwaliks of Asnot 
in the Panjab ; it contains the two last premolars, and the first and second molars ; 
the whole of the penultimate and a portion of the ultimate premolar, together with 
the first molar of the left side of the mandible, were also found with the specimen, 
and it is probable that the whole jaw existed in the rock, but was broken up by the 
native collector in extracting it. The first molar tooth is somewhat broken on its 
anterior half ; the rest of the teeth are complete. 
The second molar has only just commenced to be touched by wear on its 
anterior tubercles ; the second premolar has a small dentine surface exposed on its 
summit ; the summit of the first premolar is only blunted ; both these teeth have 
not been protruded to their full height above the jaw ; the animal was evidently 
adolescent at the time of its death. 
The crown of the second molar, being the most complete, this tooth is here 
selected for description ; the shape of the crown is oblong, having four conical or 
mastoid prominences at its angles ; a cruciform valley divides these prominences 
or cones ; the transverse portion of this valley is considerably the wider and deeper 
of the two ; the extremities of this transverse valley extend downwards to the base 
of the crown ; in the central hollow between the four cones there is a flat bi-lobed 
tubercle ; a large talon-tubercle occupies the hindmost portion of the antero-pos- 
terior valley, while a flatter tubercle occupies the anterior extremity of the same 
valley ; there is a very small and conical tubercle at the outer extremity of the 
transverse valley. The plane of wear of the molars, as shown on the first molar, 
slopes slightly towards the outer side ; there is no trace of a cingulum on any por- 
tion of the molars. 
Turning now to the premolar teeth, of which these are the only known speci- 
mens in existence, we find them of a most abnormal and interesting character ; 
these teeth are of a considerably larger size than the true molars, a character 
which is, I believe, unknown among other Ungulates^ though it occurs in the dental 
system of Fteropus. The premolars are placed in direct contact with the molar 
series, and in form have a general resemblance to the corresponding teeth of Hip- 
popotamus, Merycopotamus, and AntJiracotheriwm ; each tooth is inserted into the 
jaw by two fangs ; the penultimate premolar does not present any disc of pressure 
( 79 ) 
