. Boston journal of natural history. Natural history. 148 Couthouy on Coral Formations vature of the hills to the south, and sometimes almost skirting them at from the fourth of a mile to a mile from the shore. The figure below represents a north and south section of the plain, from just back of the ancient beach to the sea, on a scale of inches to a mile, and 10 feet to the a. Surface soil, twelve to fourteen inches deep below the old beach, and eighteen to twentysix inches deep above it. h. A decomposed lava ten or twelve feet thick, gradually passing into the solid rock. c. A mix
. Boston journal of natural history. Natural history. 148 Couthouy on Coral Formations vature of the hills to the south, and sometimes almost skirting them at from the fourth of a mile to a mile from the shore. The figure below represents a north and south section of the plain, from just back of the ancient beach to the sea, on a scale of inches to a mile, and 10 feet to the a. Surface soil, twelve to fourteen inches deep below the old beach, and eighteen to twentysix inches deep above it. h. A decomposed lava ten or twelve feet thick, gradually passing into the solid rock. c. A mixture of decomposed lava, surface mould, and coral and shell detritua. d. Ancient beach of coral rubble, shells, and volcanic earth and sand. c. A stratum of like materials with c. ten inches thick at its commencement, but gradually attenuating as it approaches the sea till at one-fourth of a mile from it, it is lost. /. A stratum of fine volcanic sand, chiefly comminuted crystals of olivine, and fine coral detritus and shells. g. Thin laminae, the planes of whose stratification are parallel, formed by a concretion of the materials of/. and having thin layers of locjse sand interposed. h. Present beach—coral rubble, shells and sand, chiefly coral detritus. These laminae were evidently formed by successive hori- zontal depositions, but have since been tilted up so as to dip about 5*^ north to the sea. Proceeding inland, after passing the line of old beach, the surface soil is twice the thickness of that on the seaward portion of the plain, and rests on the stratum of decomposed lava. The layer of mixed earth, sand and shells, was no doubt washed from the stratum at the time when the sea was at the old beach. The bed of sand and detritus on which this mixed layer, and after its disappearance, the surface mould rests, is full of slight inequalities, as if rip- pled up by the wind or sea. Probably the former was the real agent after its elevation. In the opinion of several intel-
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