A. E. Verrill—The Bermuda Islands; Geology. 109 
33a, 330.) In the latter case the cliffs are apt to be undercut, 
between tides, and usually somewhat above high-tide level, owing 
to the dash of the waves and spray in storms. The zone from 
about half-tide to 10 to 20 feet above is usually deeply pitted and 
very rough, as already described (p. 66). 
If the strata are nearly horizontal and unequal in hardness the 
undercutting will vary in amount, making two or more projections 
and intervening grooves (figs. 15, 17). When the strata are irregular 
in position and variable in hardness the undercutting and conse- 
quent falling away of the cliffs in large masses give rise to all sorts 
of fantastic forms. (Figs. 8, 10, 17, 20, and pl. xxii.) 
Sometimes, when the rocks vary greatly in hardness, due to the 
presence of large beds or masses of unconsolidated sand and to the 
hardening by infiltration of particular parts, as described above 
(p. 63), the rapid erosion of the softer beds or masses leaves the 
harder parts projecting in the form of partly or wholly detached 
pillars, pyramids, pinnacles, or columns, often of considerable height 
(fies: 105 is pl. xxin), 
* Pulpit Rock,” on Ireland Island, is a good example of such a 
detached pinnacle rock (fig. 22). It also shows well the irregular 
stratification of the zeolian limestone. Some of these pinnacles stand 
out some distance from the shore, on the flat reefs, showing where 
an islet or the shore cliff once stood. 
The formation of pinnacles and towers is well shown at the eastern 
end of the islands, especially at Tobacco Bay, on St. George’s (fig. 
10 and pl. xxii, fig. 1), and on the eastern shores of St. David’s and 
Cooper’s Islands, and at some points on the south shore (pl. xxii, 
fig. 2). 
In many of these places every stage in the process of forming 
these columns can be seen, as well as their undercutting and final 
overthrow, by which high islets and shore cliffs become eventually 
converted into flat tidal ledges, and detached flat reefs, or even into 
serpuline atolls (figs. 27-29; pl. xxiii). 
The remarkable examples of erosion shown at ‘‘ Cathedral Rocks” 
or “Old Church Rocks,” on the western side of Somerset Island 
(fig. 9 and pl. xxiii), are similar in origin, but less broken down. 
They are probably largely due to great masses of loose sand that 
has been washed away from the bardened parts that now form the 
pillars and arches. Part of this may have been done at a former 
time, when the land stood 10 to 15 feet lower than now (see 
pp. 75-80). 
Trans. Conn. Acap., Vou. XII. 8 NovemBeErR, 1905. 
