SIWALIK RHINOCEROTIDA). 51 
Width o£ first true molar 3*1 
Length of second „ . 2’7 
Width of „ „ 3-3 
Length of third „ .....■•*••• 275 
Width of „ „ , . : 2 9 (?) 
The detached specimen of the last upper true molar figured, of half the natural 
size, in plate LXXII, fig. 7, of the “ Eauna Antiqua Sivalensis,” I have compared, 
by means of a cast, with the corresponding tooth in the set before us, and I find that 
the two are identical in form. The detached specimen seems rather the larger of 
the two, but this is, at all events partly, due to the other not being fully protruded. 
The length of the detached specimen is 3 2, its width 3T, 1 and its height 3T 
inches. This tooth shows very clearly the pit at the posterior angle. The tooth 
drawn in figures 12 and 12a of plate LXXY of the “Eauna Antiqua Sivalensis ” • 
seems to be another view of the same specimen. 
A specimen of the first or second upper true molar, represented in figure 6 of 
plate LXXII of the same work, is stated in the description of the plate to have a 
length of 2 3 and a width of 3*4 inches. The dimensions taken from the figure, 
however, would give a length of 3*6 and a width of about 3 inches. Similarly, the 
dimensions of the specimen drawn in figure 11- of plate LXXY of the same work 
would have a length of 4 and a width of 3 inches ; this specimen is, however, 
restored, and the length is probably excessive. These two molars, if drawn to 
correct scale, would indicate that they belonged to a larger skull than the one above 
described. In general characters these teeth seem to agree with the true molars 
figured here ; they, however, possess a more complex £ crochet,’ which bifurcates 
at its extremity. 
• Comparisons. — Having now shortly noticed the main characters of the skull 
and upper molars of R. platyrhinus , -we may endeavour to see with what other 
species of the genus it presents affinities. In this respect we shall of course have 
to deal only with two-horned species. 
With R. sumatrensis , the skull of R. platyrhinus presents no affinities, since 
the teeth of the two are constructed on totally distinct plans, and, as we have 
already seen, differ in regard to the relations of their inferior squamosal processes.. 
The miocene R. schleiermacheri is likewise distinguished by the form of its teeth, 
which are constructed after the Sumatran type. 
Among the European bicorn species of the pliocene and pleistocene, in R. 
etruscus, R. leptorhinus (Owen), and R. megarhinus, the upper true molars, which 
seem to conform to what we have called the £ intermediate type,’ do not usually 
present an £ accessory f ossette ’ on the worn crown, the £ eombing-piate ’ being either 
absent or, if present, not reaching the £ crochet.’ R. tichorhinus agrees the most 
nearly of all these European species with R. platyrhinus, having two horns, and 
upper molars constructed on the same general plan, with an c accessory f ossette.’ 
The cranium of the European form is, however, broadly distinguished by the presence 
This dimension is given by Falconer as 2'8 inches. 
