ire,
and the "Chillesford beds" of Suffolk--are to be also included
in the Newer Pliocene, upon the ground that they contain a small
proportion of extinct shells. Our knowledge, however, of the
existing Molluscan fauna, is still so far incomplete, that it
may reasonably be doubted if these supposed extinct forms have
actually made their final disappearance, whilst the strata in
question have a strong natural connection with the "Glacial
deposits," as shown by the number of Arctic Mollusca which they
contain. Here, therefore, these beds will be included in the
Post-Pliocene series, in spite of the fact that some of their
species of shells are not known to exist at the present day.

The following are the more important Pliocene deposits which have
been hitherto recognised out of Britain:--

1. In the neighbourhood of Antwerp occur certain "crags," which
are the equivalent of the White and Red Crag in part. The lowest
of these contains less than 50 per cent, and the highest 60 per
cent, of existing species of shells, the remainder being extinct.

2. Bordering the chain of the Apennines, in Italy, on both sides
is a series of low hills made up of Tertiary strata, which are
known as the Sub-Apennine beds. Part of these is of Miocene age,
part is Older Pliocene, and a portion is Newer Pliocene. The
Older Pliocene portion of the Sub-Apennines consists of blue or
brown marls, which sometimes attain a thickness of 2000 feet.

3. In the valley of the Arno, above Florence, are both Older
and Newer Pliocene strata. The former consist of blue clays and
lignites, with an abundance of plants. The latter consist of sands
and conglomerates, with remains of large Carnivorous Mammals,
Mastodon, Elephant, Rhinoceros, Hippopotamus, &c.

4. In Sicily, Newer Pliocene strata are probably more largely
developed than anywhere else in the world, rising sometimes to a
height of 3000 feet above the sea. The series consists of clays,
marls, sands, and conglomerates, capped by a compact limestone,
which attains a thickness of from 700 to 800 feet. The fossils of
these beds belong almost entirely to living species, one of the
commonest being the Great Scallop of the Mediterranean (_Pecten
Jacoboeus_).

5. Occupying an extensive area round the Caspian, Aral, and Azof
Seas, are Pliocene deposits known as the "Aralo-Caspian" beds.
The fossils in these beds are partly freshwater, partly marine,
and partly intermediate in character, and they are i