PART 1 .] hyMiker: Further Notices of Siwalik Mammalia. 
51 
In the above table there are a few points which call for short notice. In the 
fii’st place, the number of specimens collected from Sylhet is so small, that no 
inference as to the absence of genera from the formations of that district can be 
drawn from their absence in the table : to a less degree the same remark applies 
to Burma and Perim Island. Again, in the three columns headed respectively 
Country east of Jhelam R.,” “ Punjab, west of Jhelam R.,” and “ Sind, ” I do 
not wish to lay any great stress on the absence in any of these columns of any of 
the rarer genera, such as Sanitkermvi, AmpMeyon, or Lutra, as indicating their 
ateence from the formations under those columns. On the other hand, the pre¬ 
sence or absence in any of these columns of any of the common genera, such as 
Fueleptias, Merycopotamus, Bos or Eqims, is of great weight, and is to be considered 
in many cases as a fact in distribution. 
We may notice in Sind the complete absence of the following common 
Siwalik genera, via., Stecjodon, Loxoclon, Euel&phas, Ilfpoqiotanms, Merycopotavms, 
Camelus, Camelopardalis, Bos, Bison, sradL Epiius; and we may further note that 
most of these genera are modern forms, and that most of them are not found in 
the country to the west of the river Jhelam, but that they occur commonly 
enough in the country to the east of that river. Again the genera Dinotlierium, 
Listriodon, HyotJierium, various Suina, Hyopotamms, and Acerotherium, are of fairly 
common occurrence in Sind and the Punjab, and do not, I believe, occur in the 
country to the east of the Jhelam, with the exception perhaps of Acerotlieriwm, 
which has been found a little to the east of that river. Again the genus Equus, 
which is extremely common in the Siwalik country of Falconer, is unknown in the 
Western Punjab, and is there replaced by Eippotherium, of which genus at least 
two species occur there very commonly, of which one (H. artilopinuni) occurs 
in the more eastern country, while the other (H. ttieohaldi) is only known from 
the Western Punjab and Perim.^ 
The table in fact shows that the more modern genera are mainly character¬ 
istic of the country to the east of the Jhelam, while the Punjab, Sind, and 
Perim Island are characterized by an older facies of genera, —the greater number 
of old genera occurring in Sind. The Sind fauna is consequently to be regarded 
as the oldest of the Siwalik group, that of the Punjab and Perim Island probably 
the next in age, and the Siwaliks of the Dehra Dun and neighbouring country 
as the newest of all. I wish, however, to add that although I think the differ¬ 
ence in the mammalian faunas of the different districts under discussion are due 
in great measure to differences in relative age, yet that it is probably that many of 
the genera, such as those of the Sivatlieridce, were strictly contemporaneous, and 
were limited in their geographical range. 
' In Falconer’s catalogue of the Vertehrata in the collection of the Asiatic Society of Bengal, 
the molars of this sijccies are referi ed to Equus, I believe I have evidence of the exi.stence of 
four species of the genus in the Punjab. 
