Ch. VI] INLAND SEA-CLIFFS AND TERRACES. 73 



tality of the base-line -which constitutes the chief peculiarity of an 

 ancient sea-cliff. 



It is, however, in countries where hard limestone rocks abound, that 

 inland cliffs retain faithfully the characters which they acquired when 

 they constituted the boundary of land and sea. Thus, in the Morea, no 

 less than three, or even four, ranges of what were once sea-cliffs are well 

 preserved. These have been described, by MM. Boblaye and Virlet, as 

 rising one above the other at different distances from the actual shore, 

 the summit of the highest and oldest occasionally exceeding 1000 feet 

 in elevation. At the base of each there is usually a terrace, which is in 

 some places a few yards, in others above 300 yards wide, so that we are 

 conducted from the high land of the interior to the sea by a succession 

 of great steps. These inland cliffs are most perfect, and most exactly re- 

 semble those now washed by the waves of the Mediterranean, where 

 they are formed of calcareous rock, especially if the rock be a hard crys- 

 talline marble. The following are the points of correspondence observed 

 between the ancient coast lines and the borders of the present sea : — 1. A 

 range of vertical precipices, with a terrace at their base. 2. A weathered 

 state of the surface of the naked rock, such as the spray of the sea pro- 

 duces. 3. A line of littoral caverns at the foot of the cliffs. 4. A con- 

 solidated beach or breccia with occasional marine shells, found at the 

 base of the cliffs, or in the caves. 5. Lithodomous perforations. 



In regard to the first of these, it would be superfluous to dwell on the 

 evidence afforded of the undermining power of waves and currents by 

 perpendicular precipices. The littoral caves, also, will be familiar to 

 those who have had opportunities of observing the manner in which the 

 waves of the sea, when they beat against rocks, have power to scoop out 

 caverns. As to the breccia, it is composed of pieces of limestone and 

 rolled fragments of thick solid shell, such as Strombus and Spondylus, 

 all bound together by a crystalline calcareous cement. Similar aggrega- 

 tions are now forming on the modern beaches of Greece, and in caverns 

 on the sea-side; and they are only distinguishable in character from 

 those of more ancient date, by including many pieces of pottery. In 

 regard to the lithodomi above alluded to, these bivalve mollusks are well 

 known to have the power of excavating holes in the hardest limestones, 

 the size of the cavity keeping pace with the growth of the shell. When 

 living they require to be always covered by salt water, but similar pear- 

 shaped hollowsj containing the dead shells of these creatures, are found 

 at different heights on the face of the inland cliffs above mentioned. 

 Thus, for example, they have been observed near Modon and Navarino 

 on cliffs in the interior 125 feet high above the Mediterranean. As to 

 the weathered surface of the calcareous rocks, all limestones are known 

 to suffer chemical decomposition when moistened by the spray of the 

 salt water, and are corroded still more deeply at points lower down where 

 they are just reached by the breakers. By this action the stone acquires 

 a wrinkled and furrowed outline, and very near the sea it becomes rough 

 and branching, as if covered with corals. Such effects are traced not 



