FALCONER ON THE PERIJVI ISLAND FOSSILS. 361 



specific distinction. The specimen, however, is much too defective 

 to warrant any opinion in regard to the relations of the Perim 

 fossil to the European species, except that it was quite as large as 

 the D. giganteum. We are fortunately able to determine the 

 position of the tooth in the jaw with some confidence. The upper 

 grinders in Dinotherium have a long low basal ridge in front and 

 behind; while the same teeth in the lower jaw have hardly any 

 ridge in front, and the hind one is considerably more developed 

 than in the upper grinders, so as to form a strongly marked " talon " 

 or heel. The Perim fossil exhibits this heel of large size, while the 

 presence of an impression on the posterior surface proves that 

 there was a tooth behind it. It, therefore, belonged to the penul- 

 timate molar of the lower jaw, and apparently to the left side. 



In short, there can hardly be a doubt about the specimen be- 

 longing to a species of Dinotherium. The only question which 

 can arise is in regard to the correctness of the locality whence the 

 specimen is said to have come. It was presented to the British 

 Museum by the lady whose name is mentioned above, as a Perim 

 Island fossil, along with teeth specimens of a species of mastodon 

 known to be found in the Perim deposit. M. Konig, the eminent 

 conservator of the Palseontological department, who had early re- 

 cognised the generic relations of the fossil, is confident about the 

 donor and the mentioned locality. An additional confirmation is 

 met with in the mineral condition of the specimen. It exhibits 

 the silicified appearance, which is so prevalent in the Ava, the 

 Sewalik, and Indian fossils generally. The ivory core is fissured 

 into a vast number of radiating minute segments which have been 

 re-cemented by a siliceous paste (as has happened to certain agates), 

 and the whole of the structure, — enamel and ivory, — has become 

 so thoroughly penetrated with siliceous infiltration, that it resists 

 the knife and takes on the highest degree of vitreous polish in the 

 section, while the external surface of the enamel, from the same 

 cause, presents an opaline appearance. All the Eppelsheim 

 specimens of Dinotherium, which I have had an opportunity of 

 examining, are, on the other hand, unsilicified, softer, and of less 

 specific gravity. In section their ivory cuts under the knife, and 

 yields a dull earthy surface ; while the harder enamel takes on but 

 a very imperfect polish. This circumstance strongly confirms the 

 Indian origin of the fossil. It is very possible that the large 

 animal — " assimilating to the rhinoceros {Lophiodon ?) " — men- 

 tioned by Mr. James Prinsep in the quotation above given, may 

 also belong to Dinotherium. This conjecture is thrown out for 

 the guidance of those connected with the museum at Bombay and 

 that at Calcutta, who have access to the original specimens. What 

 we know at present must serve in a great measure as an index 

 merely to further inquiries. I would suggest in the meantime 

 designating the Perim fossil provisionally, by the specific name of 

 Dinotherium Indicum. 



The following are the dimensions of the fragment compared with 

 those of the same tooth of the Dinotherium giganteum from 

 Eppelsheim. 



