36 
MOLAR TEETH AND OTHER REMAINS OE MAMMALIA. 
Ealconer had a specimen showing these six . incisors, he did not give a figure of 
it in the ‘‘ Eauna Antiqua Sivalensis.” 
In the form of their complex molar teeth, furnished with a large crochet and 
combing-plate, B. platyrhinus and R. namadious approach the living R. mdicus 
of India ; the lower incisors of R. platyrhinm and R. indicm have also the 
same form and arrangement. Dr. Ealconer, moreover, considered the upper molars 
of R. platyrhinus to approach those of the European R. tichorhinus. Both these 
species also agree in having been bicorn. The lower incisors of R. tichorhinus^ 
however, differ from those of R. platyrhinus in having been deciduous at an 
early period. The three species, R. platyrhinus^ R. tichorhinus^ and R. indicus, 
agree in having had spatulate mandibles, and combing-plates in the upper molar 
teeth. 
The molars of the unicorn R. sivalensis are formed on the same plan as those 
of the European Rhinoceros etruscus (Ealc.), but the latter was a bicorn species, 
and had a spatulate mandible without permanent incisors. The mandible of R. 
sivalensis is like that of the African R. simus. 
The form of the cranium of the unicorn R. palmlndicus is very like that of 
the unicorn R. javanicus, and the mandibles of the two species are alike furnished 
with large outer incisors ; but the form of the upper molars is different. The 
upper molars of R. iravadicus and R. sinensis have their nearest representatives in 
those of the living R. sumatrensis. 
The upper molars of Acerotherium perimense and of R. deccanensis, together 
with the upper premolar noticed above from Sind, are cingulated on the inner side 
like those of Kaup’s typical forms of the sub-genus (or genus) Acerotherium. 
Whether any of these Indian forms were hornless or provided with four toes on the 
anterior limb, we have no means at present of knowing ; the mandible of R. 
deccanensis was spatulate and edentulous in the adult state, as in R. etruscus. 
The lower molar from Attock, described above, presents a peculiarity of struc- 
ture which is only found in the living R. simus of Africa. 
The afidnities of the Indian fossil species of Rhinoceros are therefore widely 
spread, showing relationships to forms, both living and extinct, scattered over 
Europe, Asia, and Africa. Unless the hexaprotodont character of R. sivalensis 
can be proved, there seems to be no more generalised form among the fossil than 
among the living species ; while the highly specialised outer and inner lower incisors 
is a character common to some of both fossil and living forms. 
The difficulty of determining with accuracy the lower molar teeth, in the 
absence of the original type specimens, from the Siwaliks, has prevented me from 
making new species, in any case, on the evidence of these teeth alone. In the 
case of upper premolars I have followed the same rule, from the known liability of 
these teeth to vary in different individuals of the same species. 
The three species of fossil Asiatic Rhinoceros described by Dr. Ealconer belong 
to the hysodont type of Mr. Boyd-Dawkins ; as does R. deccanensis and the three 
( 54 ) 
