estimated height of four hundred feet, extensive layers of shells, mostly
comminuted, but some perfectly preserved and closely packed in black
vegetable mould; they consisted of Concholepas, Fissurella, Mytilus,
Trochus, and Balanus. Some of these layers of shells rested on a thick bed
of bright-red, dry, friable earth, capping the surface of the tertiary
sandstone, and extending, as I observed whilst sailing along the coast, for
150 miles southward: at Valparaiso, we shall presently see that a similar
red earthy mass, though quite like terrestrial mould, is really in chief
part of recent marine origin. On the flanks of this island of Quiriquina,
at a less height than the 400 feet, there were spaces several feet square,
thickly strewed with fragments of similar shells. During a subsequent visit
of the "Beagle" to Concepcion, Mr. Kent, the assistant-surgeon, was so kind
as to make for me some measurements with the barometer: he found many
marine remains along the shores of the whole bay, at a height of about
twenty feet; and from the hill of Sentinella behind Talcahuano, at the
height of 160 feet, he collected numerous shells, packed together close
beneath the surface in black earth, consisting of two species of Mytilus,
two of Crepidula, one of Concholepas, of Fissurella, Venus, Mactra, Turbo,
Monoceros, and the Balanus psittacus. These shells were bleached, and
within some of the Balani other Balani were growing, showing that they must
have long lain dead in the sea. The above species I compared with living
ones from the bay, and found them identical; but having since lost the
specimens, I cannot give their names: this is of little importance, as Mr.
Broderip has examined a similar collection, made during Captain Beechey's
expedition, and ascertained that they consisted of ten recent species,
associated with fragments of Echini, crabs, and Flustrae; some of these
remains were estimated by Lieutenant Belcher to lie at the height of nearly
a thousand feet above the level of the sea. ("Zoology of Captain Beechey's
Voyage" page 162.) In some places round the bay, Mr. Kent observed that
there were beds formed exclusively of the Mytilus Chiloensis: this species