A FrEliODON MACliOGNATIlUB. 
227 
condylo by a deep noteh and is slightly intleeted. The eoronoid process is incomplete. 
The dental canal (d.f.) opens low down near tlus ventral border. On the outer face of 
the mandible there are four or live foramina, of wliich the most anterior is beneath the 
alveolus of pin. 1, the ne.\t beneath the middle of pm. 2, the third and fourth beneath 
the front and hinder roots respectively of pm. d. The tliird molar is represented by its 
alveolus only. The second consists of a high anterior portion and a large talon with a 
blunt cutting-edge. The anterior portion consists of a large posterior cusp with a much 
smaller one closely united to its antero-internal side, the two together forming a very 
blunt and imperfect blade ; in Pterodon and Ilpainodon the auhn’o-internal cusp is 
enlarged and secant, and with the posterior cusp forms the powerful cutting-blade of 
the carnassials. There is no trace of a postero-internal cusp. The first molar is much 
smaller than in. 2 ; it is greatly worn, particularly on its antero-external face. The 
anterior half of the tooth is composed of a small antero-internal cusi) (paracone) and a 
larger main posterior cusp (protocone). The talon consists of an outer cusp and a lower 
inner ridge apparently continuous with the cingulum. 
The fourth premolar is much larger than m. 1 ; it is composed of a large stout main 
cusp and a small talon. The second and third premolars are simple compressed cones, 
each borne on a pair of relatively large roots. In both premolars and molars the 
cingulum is well marked. Pm. 1 is represented by its alveolus only; it seems to have 
been a one-rooted tooth squeezed outwards between the hinder edge of the canine in 
front and pm. 2 behind. The canine is relatively large, and there are three incisors 
so crow’ded together that one, probably i. 2, is displaced so as to lie above and behind 
the other two. 
The dimensions (in centimetres) of this s[)ecimen are : — 
Total length of the jaw 22 
Depth of ramus at hinder end of syiiiplij>i.s 2 
,, „ beneath in. 3 3 'J 
Length of symphysis h‘8 
Width of condyle 3 ‘3 
Distance between hinder border of the alveolus of m.3 and 
the posterior angle of the condyle 10-2 
Antero-posterior diameter of canine 2 
The dimensions (in centimetres) of the cheek-teeth are: — 
Length. Wlcitli. 
iH. 3 (alveolus) I d 
rn. 2 I d ’t) 
in. 1 1'2 '7 
pm. 4 I'T 1 
prn. 3 1-4 4) 
pm. 2 1'2 ■( 
M. 8880. 1*1 aster cast of above specimen. Made in the Brithli Ahuseum. 
C. 8815. Posterior portion of right ramus of mandible with m. 1-3 in perfect preservation (text- 
tig. 73). The description given above of the second molar in specimen (J. 8382 applies 
equally to m. 2 and m. 3 in this mandible. It can, however, be seen that the cingulum 
2g 2 
