INTEODUCTORY OBSERVATIONS. 
xiii. 
the Indian Museum. The tooth differs from the corresponding molar of M. dissimilis 
or M. nanus (fig. 2) both in its inferior size, and in structure. Its length is 0'75, 
and its width 0’8 inch ; and the external surface of the outer columns is less in- 
wardly inclined, thus causing the tooth to assume a character more approaching that 
of Chceromeryx^ which is now' provisionally referred to the Bichodontidce. Additional 
specimens are required before anything more definite can be said as to the affinities 
of the present species, which may indicate the identity of Kemimeryx with Meryco- 
potamus. 
Sivameryx. — This genus has been merged in Choeromeryx, and the latter pro- 
visionally placed in the Dichodontidce {vide “ Cat. Foss. Mamm. Brit. Mus.” pt. II. p. 
165). The type species is probably identical with G. silistrense. 
Anthracotherium, sp. — Two specimens in the British Museum {vide “ Cat. 
Foss. Mamm. Brit. Mus.” pt. II. p. 244) appear to indicate the existence of two 
additional Siwalik species of Anthracotherium^ but are not sufficiently perfect to 
afford good grounds for specific determination. The large lower Siwalik species 
noticed in vol. II. p. 176 of this work is omitted from the synopsis. 
Tetraconodon. — This genus, together with Elotheriiim {Entelodon) is now in- 
cluded in the Ghceropotamidce {vide “ Cat. Foss. Mamm. Brit. Mus.” pt. II. p. 249). 
Sus, sp. (? nov.).—An the accompanying woodcut there is represented the last 
right lower true molar of a species of Sus which is implanted in a fragment of a 
mandible collected by Mr. Theobald from the Siwaliks of the Punjab, and apparently 
indicates a species distinct from any of those described in the second part of the 
present volume.^ The tooth is in a partially worn 
condition, and has a comparatively simple talon. 
It is larger and somewhat more complex than the 
corresponding tooth of S. hysudricus (pi. VIII. figs. 
2, 3) ; and is smaller and has a rather less complex 
talon than m. 3 of 8. falconeri (pi. VII. fig. 1) : it 
agrees, however, with the latter in the lateral com- 
pression of the columns. It is very nearly equal in 
size to m. 3 of 8. cristatus, but has a less complex talon, while the main columns are 
rather more compressed, and the accessory ones smaller and more detached. The 
extreme length is 1‘55, and the width anteriorly 0 *7 inch. The greater part of an 
immature cranium of a species of Sus from the Siwaliks in the British Museum (No. 
M. 2403 — “ Cat. Foss. Mamm. Brit. Mus.” pt. II. p. 266) agrees so exactly in size 
with the present specimen that there is a great probability that the two are speci- 
fically identical ; but the immature and imperfect condition of the British Museum 
cranium renders it insufficient to afford good diagnostic characters, and it is therefore 
unadvisable to assign to this form a distinct specific name, although it is probably 
different from all the named Siwalik species. 
Hipparion. — An examination of the Siwalik specimens of Hipparion in the 
British Museum {vide “ Cat. Foss. Mamm. Brit. Mus.” pt. III.^) has led to the con- 
1 The specimen is noticed in the “ Cat. Siwalik Vert. Ind. Mus.” pt. I. p. 109 (1S85). 2 in preparation. 
JFig. 4. Sus, sp The third right lower 
true molar ; from the Siwaliks of the 
Punjab. X- Indian Museum (No. B. 
438). 
