SIWALIK MAMMALIA 
3 
to Ihjlobates} The true molars differ from those of Simla by the simple structure 
of the cusps and the absence of the rugosities on the crown surface, as well as 
by the small size of m . - and are also widely different from those of Gorilla in which 
m - 3 is much larger than either of the other two molars ; the premolars are also of 
very different form from the corresponding teeth of those genera. Compared with 
Troglodytes the fossil agrees in the form of the cusps of the true molars, in the 
relatively small size of m. 3 and the slight development of its posterior cusps and the 
oblique connecting ridge, 2 as well as in the presence of an indistinct cingulum on the 
internal surfaces of these teeth 3 ; the relatively small antero-posterior diameter of 
the premolars and the larger size of their external as compared with their internal 
cusps are also features characteristic of Troglodytes , 4 In some specimens of T. niger 
the antero-posterior diameter of the premolars is relatively greater than in the fossil 
but in others 5 it is very nearly the same. The canine agrees precisely with that of 
the male T. niger? The outer (and therefore probably the inner) incisor is relatively 
narrower than in the latter, and the diastema is thus somewhat larger, but this need 
not be more than a specific difference. In absolute size the fossil is rather larger 
than the male T. niger 7 ; its dimensions in inches being as follows : 
Interval between outer borders of second molars . . ■ . 
y y y y inner 9J fy ... 
. 
1-5 
Antero-posterior diameter of base of outer incisor 
0-3 
Transverse ,, ,, . 
. 
0-19 
Antero-posterior diameter of canine 
0-53 
Transverse ,, ,,..... 
0-51 
Length of series of cheek-teeth ..... 
Antero-posterior diameter of pm. 3 (broken) 
0-3 
Transverse • ,, ,, 
0-5 
Antero-posterior diameter of pm. 4 .... 
Transverse ,, ,, 
0-35 
Antero-posterior diameter of m. 1 
Transverse ,, ,, ..... 
Antero-posterior diameter of m. 2 
. . 0*5 
Transverse ,, ,, 
Antero-posterior diameter of m. 3 
0-41 
Transverse ,, >>••••• 
0-46 
Affinities. — The above comparisons shew that the specimen under consideration 
indicates an ape generically distinct from both Gorilla and Simla , but so close to 
Troglodytes as to leave little doubt of its identity — an identity rendered the more 
probable by the occurence of Gynocephalus in the same region. In those respects in 
which the Siwalik Troglodytes differs from the existing African species it shows 
in a still more marked degree the approach to the human type of dentition 
presented by the latter, and serves, in a small degree, to bind still closer the 
connection between the Simiulce and the ITominidce. In the inclination of the two 
1 The fossil is distinguished from this genus not only by its superior size, but by the relatively narrower premolars. 
2 See Owen “ Odontography,” p. 446. 3 Owen “Anatomy of Vertebrates,” vol. II. p. 320. 
4 Owen “ Odontography,” p. 446. 5 Compare Blainville “ Osteographie,” Genus Pithecus. pi. V. 
6 Owen. op. cit. p. 445. 7 The length of the three molars of the fossil is 131, the corresponding length in a 
male T. niger being 1*2. 
