SIWALIK MAMMALIA. 
13 
Cranium. — The type cranium is represented in pi. III. figs. I, la; a cranium 
of the existing Cobus sing-sing being represented in figs. 4, 4a. The fossil, which 
wants the horn-cores, and is otherwise damaged, indicates a species about one-third 
smaller than C. ellipsiprgmnus and C. sing-sing. It agrees with the figured recent 
cranium of the latter in the large frontal depression and foramina, the presence of 
an infraorbital fissure and absence of a lachrymal depression, as well as in general 
contour, position of the orbits, setting on of the horn-cores, and the marked ridges 
bordering the temporal fossae; it also agrees in the form of the basioccipital 
tubercles, of the tympanic bullae, and of the hinder part of the palate. The molars 
of the existing species are narrow, and have narrow external lobes with a strongly- 
marked median costa, and no inner accessory column ; in all of which respects those 
of the fossil cranium agree. The latter is, however, narrower than the cranium of 
C. sing-sing , its post-cornual portion relatively longer, and the angle formed by the 
meeting of the nasal and parietal planes considerably less open. In the two latter 
respects the species generically separated by Gray under the name of Adenota 1 make 
a nearer approach to the fossil, while Cobus leucotis comes perhaps still nearer in these 
points, and also agrees in size. 
A second Siwalik cranium in the British Museum (No. M. 487) 2 is in very nearly the 
same condition as the type, with which it agrees almost exactly, although rather wider. 
The hinder portion of a cranium represented in figs. 2, 2a of plate III. is also 
from the Siwalik Hills, and is preserved in the British Museum (No. 39559) ; it 
agrees with the type cranium in essential characters, and is therefore provisionally 
referred to the same species. The horn-cores are widely separated, rounded, and 
directed upwards, backwards, and somewhat outwards ; the horns, as in C. sing-sing , 
may have been lyrate. The relatively large size of the post-cornual portion of the 
cranium and the comparatively sharp angle at the junction of the nasal and parietal 
planes are well exhibited in this specimen. 
The females of the existing species of Cobus are hornless, and as there is in 
the British Museum the hornless cranium of an antelope (No. 39569 s ) from the 
Siwalik Hills, which agrees with the present form in size, general contour, and 
structure of the molar teeth, it is highly probable that it belongs either to this or the 
next species. 
Affinities. — The close resemblance existing between the specimens described 
above and the crania of the genus Cobus , together with the strong evidence in favour 
of the female of the Siwalik form having been hornless, indicates that the recent and 
fossil forms are closely allied, and justifies at least the provisional reference of the 
latter to the existing genus. 
Distribution. — All the specimens referred to this species were obtained from the 
typical Siwalik Hills. 
1 Compare “ Cat. Mamm. Brit. Mua. — pt. III. Ungulata Furcipeda,” pi. XI. fig. 1 (1852). 
2 This specimen was overlooked when part II. of the Brit. Mus. Catalogue was written. 
3 “ Cat. Foss. Mamm. Brit. Mus.” pt. II. p. 58. 
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