A, E. Verrill—The Bermuda Islands; Geology. 111 
Along the high shore cliffs there are many grottoes and caves that 
can only be entered from a boat, and sometimes only at low tide. 
Two large dome-like grottoes of this kind, accessible only by a 
boat at low water, are situated close together in the shore-cliff a 
short distance east of Bailey Bay. One of them is lighted from 
above by a small chimney-like opening in the roof. Such grottoes 
often contain nests of the tropic bird.* 
Small grottoes in the shore cliffs exist in many other places, and 
many are entirely submerged, under the reefs, and are the abode of 
innumerable fishes, octopi, and various other marine creatures. 
ec. Natural Arches. 
The formation of the well known “ Natural Arches” at Tucker’s 
Town beach{ is evidently due, also, to the erosion of masses of 
softer limestone, leaving the harder parts to form the sides and 
central pillars of the arches. It stands just at high tide, but in 
heavy storms great waves dash under and through the archways 
with force enough to slowly cut away the softer limestones. The 
irregular strata of rock forming the arches are considerably broken 
and show distinct vertical fissures, as if due to settling. They are 
destined to fall at no distant time. 
d. Sandy Beaches. 
On the north side of the Main Island the line of cliffs is broken at 
Hamilton Harbor, at the Flatts, at Shelly Bay,$ where there is a good 
shell-sand beach, and at Bailey Bay, where there are two short sandy 
beaches. 
e. Cliffs of Harrington Sound. 
On the cliffs of Harrington Sound, which has usually less than a 
foot of tide, and which is so completely landlocked that it never has 
large seas, the erosion presents some different phases. The cliffs on 
the sound are often precipitous, and in some places, as at Abbot’s 
Head (fig. 21), they are quite high.|| 
* These Trans., xi, p. 679, pl. Ixxii, fig. 1; ‘‘The Bermuda Islands,” p. 267, 
same plate. 
+ See pl. xxxvi; also these Trans., xi, pl. lxxii; ‘‘The Bermuda Islands,’ ’ 
same plate. 
¢ These Trans., xi, pp. 487, 473, pl. Ixxxvii; ‘‘ The Bermuda Islands,” pp. 25, 
61, same plate. 
§ See these Trans., pl. Ixviii, fig. 1; ‘* The Bermuda Islands,” same plate. 
|| See also these Trans., xi, pl. 1xxi, lxxii; ‘‘ The Bermuda Islands,” same plates. 
