143—2 INDIAN TERTIARY AND POST-TERTIARY YERTEBRATA. 
In the present memoir numerous remains belonging to various hitherto 
undescribed forms of the selenodont group, are figured and described, while, 
in addition brief notices are given of such members of the group as have 
been previously described from the tertiaries of India. It will be found that 
by far the greater number of these specimens have been obtained, by the 
exertions of Messrs. W. T. Blanford and F. Fedden, of the Geological Survey 
of India, from the lower Manchhar (Siwalik) rocks of Sind and the districts to the 
northward. 
It will further be observed that the genera are identical with, or closely allied to 
those of the European oligocene and miocene ; the later genera characteristic of the 
sub-Himalayan deposits being in the main absent. These differences indicate that 
the mammalian fauna of the lower Manchhars of Sind belongs to a lower horizon 
than that of the sub-Himalayan Siwaliks. According to the latest researches 1 it 
seems probable that the fauna of the lower Manchhars should be relegated ‘ to the 
early pliocene time,’ while that of the sub-PIimalyan Siwaliks, which are on the 
same horizon as the upper Manchhars of Sind, belongs to a later period of the same 
epoch ; there being a probability of the higher beds of the former reaching 
up into the pleistocene. In the present and succeeding memoirs the age of the 
lower Manchhars will be alluded to as £ earlier pliocene,’ and the sub-Himalayan 
Siwaliks as • higher pliocene.’ 2 It may be added that such of the older Sind 
mammalian genera as are found in the sub-Himalayan strata (and only one of those 
described here is so found) may either be later survivals, or may have come from a 
lower horizon (Nahan) than the majority of the fossils. 
The majority of the remains described in this memoir consist only of detached 
molar teeth, which are often the sole evidence on which a genus or species is founded. 
The publication of the present memoir has purposely been delayed for a considerable 
period in the hope that additional remains of the more obscure forms might be 
obtained, but as the geological exploration of Sind is unlikely to be continued for the 
present, the time has come when such remains as are sufficiently identifiable should 
be laid before the scientific world. 
Reverting to the selenodont Suina as a whole, it would seem probable that this 
group should again be divided into three minor sub-divisions. The first of these 
is distinguished by the crowns of the upper molars being furnished with five 
columns, or cusps, and may accordingly be termed the pentecusjndate division 
(Pentecuspidati). It probably comprehends at least two families ; to the best 
known of which belongs the well-known genus Hyopotamus. For this family Dr. W. 
Kowalevsky, in his classical memoirs on its osteology, 3 has adopted the name 
1 See Duncan, ‘ Quar, Jour. Geol. Soc.,’ Vol. XXXVII., p. 207, et seq. 
2 These usymmetrical terms are used in preference to ‘ upper and lower ’ or * earlier and later pliocene,’ as both the latter 
have acquired a fixed signification as indicating definite stages of the pliocene epoch, whereas the idea to be conveyed here is 
merely that the sub-Himalayan Siwaliks are higher up in the pliocene than the Lower Manchhars. 
3 ‘ Phil. Trans.,’ 1873, p. 19, et. seq. ‘ Palaontographica,’ Vol. XXII., parts 3-5. 
