216 PROCEEDINGS OF THE GEOLOGICAL S« CIETY. [JkII. 8, 



premolar 1. The guard rouud the inner bases of the premolars is 

 somewhat stouter, but at the base of the posterior area is less deve- 

 loped. The posterior combing-plate in the last upper true molar 

 does not insulate the head of the valley. In the lower molar series 

 there is not the shghtest trace of a guard. With these exceptions 

 the teeth of the two species resemble one another so closely that it 

 would be impossible to determine the separate molars of the one 

 from those of the other. These points of difference are also found 

 in R. ScJiIeiermarheri, fi'om the same locality ; but in addition the 

 teeth of the latter animal are rather higher, and the third costa 

 is more strongly marked on the posterior area of the premolar series. 



The second upper true molar of the Etruscan species bears a re- 

 markable resemblance to the last upper milk-molar of the Megarbine ; 

 so close, indeed, is this that for a long time I classified an isolated 

 tooth in the British Museum with those of the latter species, the 

 only difference observable between them being the slightly thicker 

 enamel, and the slightly more massive form of the Etruscan tooth. 

 The same mistake, however, could not happen in the case of the 

 milk-teeth of any other recent or fossil species ; for the differences 

 are so strongly marked that they need no mention in this place. 

 Thus the permanent molar series of R. Etruscus is closely related to 

 several of the Miocene species, and especially to that of A -erotJie- 

 rium incisivum andjS. ScMeiermachen, the only exception being that 

 one of the teeth is represented in the milk- dentition of Rhinoceros 

 megarhhius ; we are therefore compelled to admit the Miocene cha- 

 racter of R. Etruscus. Of the three other Pleistocene species, 

 Rhinoceros tichorhinus, the most modern of them, stands in close rela- 

 tionship with the R. simus of India, while R. megarhinus and R. 

 leptorhinus of Owen are closely related to the bicorn Hhinoceros 

 of Sumatra. The Etruscan species, on the other hand, stands aloof 

 from all these, and is to be viewed as the last representative of a* 

 Miocene type that lingered on into the first stage of the Pleistocene 

 period, its peculiar adult dentition being found in none other of the 

 Pleistocene species ; and with it the hypsodont form of tooth universal 

 in the Miocene of Europe became obsolete. 



7. Range in Space and Time. — I have now, in conclusion, briefly 

 to review the range of the sj)ecies in space and time. It has not yet 

 been proved to have existed in Germany*, nor has it been found 

 elsewhere in any deposit of clearly Postglacial age. It wandered 

 over the Italian portion of the Pliocene continent along with Elejyhas 

 vneridio7ialis, E. antiquus, Hippopotamus major, and Rhinoceros me- 

 garhinus. Thence it passed northwards, together with the great 

 bulk of the Italian Pliocene fauna, into France, and westward into 

 Spain, and advanced as far north as the low-lying country that now 

 forms the bed of the German ocean, where it occurs in the Pre- 

 glacial forest of the Norfolk and Suffolk shore. Its abundance 



* The animal from Faxland, near Carlsruhe, described and figured by Her- 

 mann von Meyer under the name of R. Merki, is considered by M. Lartet to 

 belong to the Etruscan species. If this determination be true, the range of the 

 animal must be extended to the valley of the Rhine. 



