ADDITIONAL SIWALIK PERISSODACTYLA AND PROBOSCIDIA. 11 
which occurs in some of the most specialized recent and later tertiary rhinoceroses 
probably indicates that the stock of A. perimense (in which this buttress is strongly 
developed) diverged at an early stage from that of A. hlanfordi (in which the buttress 
is small). It may be mentioned that the ante-crochet of the upper molars of the 
rhinoceroses is another feature which disappears in the later forms ; being quite 
unknown in all those of the present day. 
It thus seems probable that A. incisivum^ A. hlanfordi^ and R. sivalensis, var. 
gajensis had a common ancestry in some part of the miocene ; and that the latter 
form gave origin to var. intermedins of the loAver Siwaliks, which overlie the Gaj 
beds, and that again to the typical ll. sivalensis of the upper Shvaliks, from which 
the living Javan rhinoceros may have descended. The exact relationship of A. 
hlanfordi to A. incisiviim cannot yet be determined; neither is it certain in which 
direction the migration of the connecting forms took place. From the occurrence 
of the Graj variety of B. sivalensis in the upper miocene of India, and that of 
A. incisiviim in the upper miocene, and possibly in the lower pliocene, of Europe, and 
from the distribution of A. hlanfordi (as noticed below), it seems, however, not 
improbable that the common ancestral form originated in the countries between India 
and Europe, and that the Styrian A. austriacum may be another branch of the same 
stock. 
Distrihution. — Remains of A. hlanfordi \\QNe, been obtained from the Punjab and 
the Bugti districts ; and whereas the species ajDpears to have been very rare in the 
former, it appears to have been as common in the latter area. This is noteworthy, 
since it would be expected that an Indian species exhibiting affinity with a European 
form would occur most abundantly on the western side of the Indian area. 
A considerable part of the skeleton of the smaller race of the present species 
has been obtained and may perhaps form the subject of a future memoir. 
Family: EQTJIVAE. 
Genus: HIPPOTHERIUM, Kaup. 
Species : Hippotherium antilopinum, Falc. and Cant. 
Object of present notice. — A large series of the remains of this species (together 
with those of H. theohaldi) have been described in the third part of the second 
volume of the present work ; but at that time no specimen of the cranium Avas 
knoAAm. This desideratum has been supplied by the specimen forming the subject 
of the present notice ; which has been already briefly alluded to in the ‘ Records 
for 1883. 
Cranium . — The cranium mentioned above is the property of Mr. Theodore 
Cooke, LL.D., F.G.S., of Poona, India, who has kindly lent it for description. It 
was obtained from the Siwaliks of Perim Island ; and is represented, of half the 
natural size, in figures 1 and 2 of plate III. : the cheek-dentition of the left side 
1 Vol. XVI., p. 94. 
