SIWALIK MAMMALIA. 
15 
Cranium. — The type cranium is represented in pi. IV. figs. 4, 4a, and a second 
specimen in fig. 5 ; the former shows the greater part of the face, but lacks the 
hinder part of the occiput, while the latter shows the whole of the occiput, but has 
lost the anterior part of the face ; there are some slight differences in these two 
specimens, which cannot, however, be regarded as of more than individual value. 
The general contour of the skull indicates without doubt that the species belongs 
to Alcelaphus, and in order to exhibit this affinity the crania of the existing A. tora 
(fig. 1) and A. pygargus (fig. 2) have been figured for comparison. 1 The fossil agrees 
with A. torn (with which may be grouped A. caama and A. bubalis) in its extremely 
elongated face, characterized by the straight infraorbital profile, and the long 
terminally-expanded nasals, which form a bold median ridge bounded by deep 
hollows in the lachrymals and maxillae. The horn-cores are, however, placed 
directly over the orbit as in A. pygargus (which agrees in this respect with A. albifrons 
and A. senegalensis ), instead of being pushed back to the vertex of the cranium as in 
the A. tora group, 2 and the occipital and parietal planes are consequently distinct, as 
in the former group. 3 The direction of the horn-cores is nearly the same as in the 
A. pygargus group, which also agrees with the fossil in the concavity of the facial 
profile at the orbit, although differing in the perfect straightness of the infraorbital 
portion. 
Young cranium. — The young cranium represented in figs. 3, 3a, is the type of 
A. ba/ceri, which was regarded as allied to the A. pygargus group. The opportunity 
of comparing this specimen with the one represented in fig. 5 has, however, con- 
vinced the writer that the two cannot apparently be specifically separated ; the 
shorter face of the young specimen being probably due to its immaturity. 
Molars. — The second and third left upper true molars of the Calcutta specimen 
are represented in fig. 5a. These teeth agree with those of existing species of the 
genus in their extremely narrow form, and the absence of any trace of the internal 
accessory column. 
Affinities. — The present species may apparently be regarded as one intermediate 
between the A. tora and the A. pygargus group, being allied to the former in the 
characters of the face, and to the latter in those of the postorbital portion of the 
cranium. Judging from the analogy of the genus Bos , the A. tora group is the more 
specialized of the two, and as it is probable that the facial would be more readily 
modified than the occipital region of the cranium, it is interesting to find that in the 
Siwalik form it is this part which has assumed the specialized character. The 
intermediate nature of A. palceindicus fully confirms the conclusion now generally 
entertained as to the generic unity of the A. tora and A. pygargus groups. 
1 The absence of a lachrymal fissure and of supraorbital pits, the presence of a well-marked lachrymal depression, and 
the narrow crowns of the cheek-teeth are characteristic features of the genus. 
2 Compare Gray “ Cat. Mamm. Brit. Mus. — pt. III. Ungulata Furcipeda.” pi. xvi. fig. 1 (1852). 
3 When describing the type specimen in the “ Cat. Foss. Mamm. Brit. Mus.” pt. II. the writer thought that the post- 
cornual portion of the cranium would be much shorter than it really turns out to be, and he therefore considered the species 
nearer to the A. tora group than now seems to be the case. 
