SPAIN AND PORTUGAL 45 



Though no Mammalian remains nor land shells 

 have been discovered in the Channel Island Loess, 

 land shells have been found in the Loess of the island 

 of Bre'hat, situated off the adjacent coast of Brittany, 

 the structure of which is similar to that of the 

 Channel Islands. 



We have here, therefore, on a small scale, results 

 precisely analogous to those exhibited on a larger 

 scale on the Continent. I look upon this case as a 

 crucial test in favour of the Submergence hypothesis. 

 It fulfils all the conditions of the problem in a way 

 no other interpretation of the phenomena admits of. 1 



Spain and Portugal: Gibraltar. Here we find few 

 traces of the Eaised Beach or the Head, for the force 

 of the Atlantic waves on the western coasts of the 

 Peninsula has been such as to denude or altogether 

 remove these littoral deposits. Nevertheless, there are 

 sufficient, though slight, traces to show that both the 

 beach and the Head were originally continued to 

 the Straits of Gibraltar. There is reason to believe 

 that all the lower ground and hills in the inter- 

 mediate area between the Rock and the south of 

 France was submerged in like manner. 



The later physical history of the Rock of Gibraltar, 

 has been investigated by Dr. Falconer, 2 Mr. G. Busk, 3 



1 See my paper in Phil. Trans., 1893, p. 915. Mr. A. 

 Oollenette's interesting observations, made independently, have 

 led him also to conclude that Guernsey has been submerged at 

 some recent time. He differs however from me in his account of 

 the " Head." Trans. Soc. Nat. Science for 1892 : Guernsey, 1893. 



2 Palceontological Memoirs, vol. ii., p. 556. 



3 Trans. Zool. Soc., vol. x., p. 2. 



