Page:Quarterly Journal of the Geological Society of London, vol. 33.djvu/228

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190
A. LEITH ADAMS ON GIGANTIC LAND-TORTOISES ETC.

and that he had not touched upon any geological questions in it. No judgment could be formed from Sicilian deposits, as there seemed to have been no connexion between the islands; and with regard to the Maltese deposits, he stated that remains of Hippopotamus were found in breccia and in conglomerates in rock-cavities which appeared to have been caves, and also in fissures with red soil like that of the surface, containing angular fragments of the parent rock. In one cavity he found whole carcasses of Elephants, just as if they had been carried in suddenly, and filled in with earth by a wave. The remains might have been derived from a Pliocene deposit broken up and swept into the cavities.

Prof. Ramsay remarked that when the small Maltese Elephants were first described he thought they were generally spoken of as Miocene; but this might be a misunderstanding. It was, however, confirmed by the prevalence of Miocene rocks in Malta; but the gisement of these remains might be of later date. He was much struck by the number of Tortoises, but regretted that it could not be decided whether those from Gibraltar were land or freshwater species. If the latter, their presence was exceedingly interesting, fresh water being now so scarce in Gibraltar; and such remains occur in Gibraltar high up in the rock, where there is now no water. This, it seemed to him, would indicate an enormous change in the physical geography of the region. In a late visit to the north coast of Africa, near Tangier, he had found what were probably Jurassic strata very much contorted, and above them Coralline sands, half consolidated at their junction with the Jurassic rocks; and here on the old land surface he obtained a jaw of an Elephant, containing a molar tooth which proved it to belong to E. antiquus. This was interesting, from the alliance of that species with the existing African Elephant. From his point of view, he said, the chief interest of the paper was its bearing upon the changes in the physical geography of the Mediterranean and Aralo-Caspian areas.

Prof. T. Rupert Jones remarked that some of the Maltese gravels contain rock-matter not now existing in Malta. This indicates a great lapse of time, a great depth of rock having been washed away.

Prof. Seeley inquired whether the author had examined into the affinities of the large Maltese Chelonia and those from the Siwaliks. He noticed differences in the form of the femur, reminding one of the Indian forms, but perhaps indicating a still closer relationship to American types. He inquired whether there was any apparent relation of descent between the Miocene and later forms, and remarked that it seemed to him there was evidence proving the migration of animals and plants, with specific modification, from east to west. With regard to the thickness of the plates of the carapace and plastron, he said that this was no evidence of size. Thus Emys crassus, although but a small species, has plates at least as thick as those from Malta; and he had seen a Kimmeridge-clay species which illustrated the same fact.