472 A. E. Verrill—The Bermuda Islands. 
coral reefs, and are the abode of innumerable fishes, octopi, and vari- 
ous other marine creatures. (See plate Ixxiii, and Part VI.) 
The character and mode of formation of these caves and grottoes 
will be more fully discussed later, under Geology. 
8.—Shore Cliffs ; Natural Arches ; Pinnacies. 
Along nearly the whole length of the southern sides, and on parts 
of the northern shores of the islands, there are broken and very rough 
cliffs of limestone, often of considerable height, and not infrequently 
perpendicular or overhanging. The irregular stratification of the 
limestone, with layers of unequal hardness, and sloping in all diree- 
tions, which is characteristic of all such zeolian limestones, causes 
this rock to be admirably suited for the ocean waves to carve into 
curious and fantastic forms. 
Figure 24.—Chasm and Natural Bridge on Coopev’s Island. 
In some places former headlands have become detached from the 
shore and worn by the waves into towers, pyramids, pinnacles and 
other curious forms, which are often very picturesque. The surface 
of the rock is deeply eroded and honeycombed by the spray, and 
covered with hard, projecting, sharp points, so that it looks very 
rough -and weather-beaten, and it is certainly very rough to climb 
over. In most places, where long exposed, it has a dark color. 
