i893. ARE OCEAN DEPTHS PERMANENT ? 185 



of the Alps, and continue far away to the East, to Persia, and have 

 been met with by Griesbach near Balk, on the Oxus. Then these 

 deposits were folded, in the Taurus, in Asia Minor, in Switzerland. 

 Afterwards came the sagging-down of certain parts of these folds, 

 near Vienna, in Hungary, &c., and all that varied series of con- 

 sequent events. After the first Mediterranean came the formation of 

 an immense horizon of salt deposits, stretching from Wieliczka to 

 Persia ; then a second Mediterranean reaching far into the newly- 

 formed depressions ; then the appearance of vast fresh-water lakes, 

 lasting through a long period of time till the breaking down of the 

 ^gean land and the re-conquest of the Black Sea. 



Look at smaller examples of such partial subsidences ; see 

 Margerie's instructive paper on the Corbieres, showing the sinking 

 down of the Pyrenees, Miocene beds passing beyond Narbonne, while 

 south of Cape Leucate two more recent Pliocene " effondrements " 

 form the Rousillon, described by Deperet, and the Golfe de Rosas. 



But this is only part of the Tethyan history. Michelin's and 

 Duncan's palaeontological studies in the West Indies have revealed 

 the European character of certain deposits. It is the " Gosau type " 

 of the Cretaceous which appears in Jamaica, and the Castel- 

 Gomberto horizon of Upper Oligocene (warm type of Sables de 

 Fontainebleau) is known in several other isles. In regions still further 

 off, one of our first masters, the venerable Dr. Philippi, has shown 

 that the present molluscan fauna of the Chilian coasts is of quite 

 recent origin, and that until the beginning of Quaternary times the 

 European Mediterranean molluscan types stretched far down the 

 western coast of South America. At the same time the Mesozoic 

 deposits of Chili, and those recently discovered at Taylorville in 

 California,' show purely European characters, and the Neocomian of 

 Bogota is the exact equivalent of that of Barreme. 



These facts teach us that an ocean-bed existed, but that some 

 coast-line, maybe only an interrupted line, once stretched across the 

 present Atlantic, and permitted the Gosavian and Oligocene corals, and 

 the Miocene shells also, to cross. I do not overlook the fact that Dr. 

 Philippi himself, struck by the analogies existing between the flora of 

 Chili and that of Europe, recently refused to accept the hypothesis 

 of a "bridge" to Europe, and preferred to suppose that identical 

 climatic and other external causes produced analogous and even 

 identical species of terrestrial plants. I refer to what has been 

 excellently said by Mr. Blanford on this theory, a few years ago, 

 in his address to the Geological Society of London. I believe that 

 the parallel correspondence of the marine faunas up to the Qua- 

 ternary period gives a more correct clue to the correspondence of the 

 existing terrestrial floras in Chili and in Europe. 



So I think that we must not only concede the extinction of a great 



1 See Hyatt and Dillen on the Jura and Trias at Taylorville, California. Bull. 

 Gcol. Soc. America, 1892, pp. 369 — 412. 



