50 INDIAN TERTIARY AND POST-TERTIARY VERTEBRATA. 
These measurements show that the three skulls have almost precisely the same 
dimensions ; indeed, almost the only exception occurs in the occipital condyles, which 
appear smaller in one of Ealconer’s spcimens ; this, however, is very probably due 
to their having been injured. 
Upper molars. — In plate VIII of this volume there is figured the upper molar 
dentition of the right side of the skull described above, drawn of two-thirds the na" 
tural size, from the cast in the Indian Museum. These teeth have already been shortly 
noticed on page 30 of the first volume of this work ; but as they are now figured for 
the first time, they may be described somewhat more fully. In reference to these 
teeth the note of Ealconer’s, already referred to, published in the “ Palaeontological 
Memoirs ” must be cited ; it is as follows : — “The molars are in fine condition, six on 
either side. The last true molar is only just touched by wear. The last true molar 
is exactly like [that of] R. liemitcechus, in having a posterior basal funnel-shaped 
pit ; while the penultimate and ante-penultimate true molars, and the penultimate 
and ante-penultimate premolars, 1 have each three distinct fossettes as in Rhinoceros 
tichorhinus. The vertical ridges of the outer side are very well pronounced in three 
valleys ( sic.)’ > 
This note gives a fair general idea of the characters of the teeth in question. 
The three anterior teeth (pm. 2, pm. 3, pm. 4) are shown to be premolars, from the 
fact of the last of them being less worn than the first true molar (m. 1). The first 
premolar (or ? milk-molar) has probably been broken off subsequently to the death 
of the animal, as its ‘ fangs ’ are still visible. The teeth belong to that form we have 
agreed to call the ‘ Indian type.’ The ‘dorsal’ surface of each tooth is approximately 
straight, and carries two very distinct vertical ridges or ‘ costse.’ In the first true 
molar the hind-most of these ridges is much smaller than the other ; in the second 
molar this ‘ costa ’ has nearly, and in the last quite, disappeared ; there is no trace of a 
‘ buttress ’ at the an tero- external angle of the crown. The ‘ crochet ’ and the ‘ comb- 
ing-plate ’ are united, and enclose between them an * accessory fossette,’ as is well 
exhibited in the first and second true molars (m 1. m2). The last true molar of the 
left side shows at its posterior angle a minute in-folding of the enamel, repre- 
senting the ‘ posterior valley ’ of the earlier teeth. A similar fold has already been 
shown to exist in the corresponding tooth of R. sivalensis and R. javanicus, and is, 
therefore, not, as one might be led to suppose from Dr. Ealconer’s note, peculiar to 
the present species and R. leptorhinus {Jiemitcechus ) . 
The dimensions of the molars of this specimen are as follows : — 
Length of second premolar l - 75 
Width of „ „ .2-1 
Length of third „ 2'0a 
Width of „ „ 2-4 
Length of fourth „ 21 
Width of „ „ 2‘5 
Length of first true molar 2’4 
1 In the “ Palaeontological Memoirs ” the word “milk-molars ” occurs here; this is clearly a slip of the pen in Dr. 
Falconer 's note-book, and has accordingly been altered. 
