observed on the Rochs on the Shores of Greece. 339 



either by ancient or modem alluvium ; caverns as numerous in 

 the Morea as everywhere else, but which it is very difficult to 

 observe, because they still serve as an issue to the waters of ba- 

 sins shut up in the interior, and because their opening is almost 

 always beneath the level of the sea. It is not one of those ca- 

 verns produced by falling in of rocks, so common in the sides 

 of valleys, a result of the destruction of loosely aggregated 

 strata, and which present in their roof the surface of more du- 

 rable strata, and in their walls surfaces constantly angular. It 

 is a third sort of cavern, which we may designate under the 

 name of littoral cavern, and which we ought to find in the inte- 

 rior of up-raised continents *. Their characters will be to exhi- 

 bit, in the same country, a nearly uniform level, walls rounded 

 in their lower part, and rocks decayed or rotten without being 

 angular, solid vaults, no communication by successive cham- 

 bers or galleries, but only by fissures widened at the bottom ; 

 finally, a demi- vault cut through the face of the rock rather 

 than a complete one. They should doubtless likewise exhibit 

 peculiar zoological characters. 



The limestone rocks are, then, everywhere hollowed at the 

 level of the tide ; there thence results either a groove or a series 

 of cavities and caverns with peculiar forms ; and, in consequence 

 of this action, whatever it may be, continued since the sea as- 

 sumed its present limits, a submarine table, but narrow in mar- 

 bles and compact limestones, and much more extended in the 

 more easily decomposed greensand. These characters, and par- 

 ticularly the last, should be found in the old shores of our re- 

 cent formations. I believe I am able to refer to it a remarkable 

 fact, to which I call the attention of geologists who shall visit 

 the Mediterranean basin. It is the existence of four or five ho- 

 rizontal steps or ledges, perfectly delineated on the littoral rocks 



" I could cite many other localities where I have observed littoral caves. 

 One of the most remarkable and best known is the Island of Sphacterie, and 

 particularly the long and narrow rock which forms the entrance of Navarino. 

 One of these caverns traverses the rock, and joins the ocean and the road- 

 stead by a rounded vault, fifty feet high. Large boats might pass through 

 it, if the shallowness did not prevent them. Saussure mentions caverns of 

 tbe same description in the environs of Nice ; he is the first geologist, and 

 nearly the only one, who mentions grooves on limestone rocks. 



