180 
TEliTJAEY VEETEBEATA OF THE FATtlM. 
only by a singlo-rootcd stnni]), and between it and pm. 2 is a s])ace of 2'5 cm. Pm, 2 
is a two-rooted tooth with a compressed conical crown, tlie anterior and posterior 
borders of whicli form sharp edges. A ridge runs down from the summit on the 
])Os((‘ro-internal surface, dividing tlie inner face into a larger anterior fossa and 
a smaller posterior rugose fossa, which looks inwards and backwards. The cingulum is 
developed on the inner side of the tooth, particularly towards the posterior end, and it 
is also present for a short distance on the postero-external side. The third premolar is, 
on the whole, similar to yrut. 2, from which it is separated by a short interval. The 
cingulum, however, is l)etter developed, and forms a sort of small talon })osteriorly. 
The postero-internal ridge is also more strongly developed. The fourth ])remolar is larger 
and is much wider posteriorly, where the cingulum forms a well-marked prominence ; 
the postero-internal ridge is still more strongly developed, its lower end almost forming 
a tubercle, though it cannot be said that, even in this tooth, there is any distinct inner 
cusp. The molars consist of two pairs of cusps, the outer being crescentoid, the inner 
])yramidal ; both are much lower than in the typical Oligocene s])ecies of the genus, 
and approximate closely to the type seen in Prachpodas, so that if it were not for the 
greatly elongated symphysis this animal might perhaps have been referred to that 
genus. In wear, the anterior limb of the postero-external crescent is seen to be divided 
into two ridges, one running forwards and inwards across the main transverse valley to 
the base of the antero-internal cusp, the other running inwards and joining a ridge 
running forwards from the postero-internal cusp, thus forming the anterior boundary of 
a fossa lying between the outer and inner posterior cusps. In Prachpodus and the later 
forms of Ancodon the same fossa is present, but its anterior border is formed by the 
main anterior arm of the postero-external crescent. The talon of m. 3 consists of a 
large crescent forming its outer side and a prominent ridge forming its inner edge, the 
two enclosing a w^ell-delined fossa. The talon, as a whole, is broader and more massive 
than in the later forms of Ancodon, and is much like that found in PmcJipodus. 
The dimensions (in centimetres) of this, the type specimen, are : — 
Approximate lengtli of mandible 
„ „ symphysis 
Depth of ramus behind 3 
Height at coronoid 
The dimensions ( in centimetres) of the teeth are : — 
2 
pm. 3 
2011 . 4 
no 1 
')ii. 3 
Lengtli of molar series 7'2. Length of |)remolar 
pm. 1) 8'(). 
34 
9 
4-5 
11 app 
Length. 
Width. 
1-5 
•'.» 
1-8 
M 
1-8 
1-2 
1-7 
1-2 
2 
1-6 
3-3 
1-8 
series (including 
The diastema between the canine and pm. 1 is 2‘2, that between pm. 1 
is 2'r). 
and pm. 2 
M. 8881. ITaster cast of the above specimen. 
Made in the British Museum. 
