19(5 ON THE STRUCTURE AND CLASSIFICATION 
, . .V, f fhP bases overlap ; when complete, the series of the 
The incisors are closely set so a curves; the crowns are pointed and 
sides prabably ‘"°el”nd imfibrmly con^x anterior slope. The canine 
recurved witli a low postcn . . the base of the outer surface is slightly 
is loa>^ ™ ^ double'fang on the inner snrfaee. The premolar, 
grooved mt thei rs distinct diastema ; they have a uniform pattern; m 
are rvulely set but there over pm, and pm,. The 
;"fT,ri-v:i‘uhoC in r. occisor (Mes. Mamm., H. IV, hg. 2); it has a low 
use centml cusp, with a distinct internal cingulum, and anterior and posterior bi^l 
cl rrcb are sl^itlv raised above it. In pm, ( r. /crox), the central cusp is higher 
lid the basal cusls more distinct. In pm. and pm, the central cusps are lofty fte 
internal cingulum pronounced and erenate, and the basal cusps much more elevated. 
The molar, have a prominent serrate or indented cingulum embracing the inner face 
and the anterior and posterior slopes of the crown ; in m, and sometimes in m» the cm- 
giilum forms a distinct cusp u,»n the posterior slope. The crown consists of thr« 
Larly cmct lonical cusps, set in line and partially confluent at the base The 
posterior surfaces of the two forward cusps, a and i, are slightly loss convex than the 
anterior, and tlie central cusp is the most elevated. 
The maxillary dental series of T ferox. A fragmentary maxilla (No. 47.788), 
wliicli lisus been acquired since the publication of Professor Owen’s memoir, contains 
the canine and three foremost premolars, and, excepting the upper incisors, completes 
our knowledge of the dentition of Triconodmi, adding as an important character the 
bifanged upper canine. This specimen agrees in size and minor details with those 
which Profes,sor Owen has referred to T Ferox, but it is, of course, quite possible that 
one and all of these specimens belong to other species, the principal ground of corre- 
lation lieing similarity of size. The maxillary series have, in general, a uniform 
stnicturc with the mandibular. They differ principally in the bifanged canine, in the 
jiresence of a cingulum on both the inner and outer surfaces of the molars and pre- 
molars, finally in the smaller relative size of 'pv'?. The canine is a powerful tooth, 
imiilanted by two stout fangs ; the anterior border is convex and nearly vertically 
])laced ; the jiosterior is concave. The premolars are known from three specimens ; 
the first (No. 47,788), presents the inner view of the canine and the second 
(No. 47,778) gives the outer view of prn^, also of the third (No. 47,779) gives 
the inner view of jinv^, m^'^ and part of So far as these specimens overlap each 
other they agree in all essential characters, and we are justified in superjiosing them 
as in figure 4. In the inner cusp has a faint indication of the anterior basal 
cusp, while the posterior basal cusp is much more prominent than in the loAver molars; 
the prominent cingulum slightly overlaps the base anteriorly, and is produced into a 
cingidum cusp posteriorly. repeats these characters on a larger scale, with a 
greater distinctness of the anterior basal cusp. Pm^ is only slightly larger than 
