st-a-dire alors loin des cotes,
le fond des eaux ne parait plus etre habite, du moms dans nos mers, par
aucun de ces animaux" (1. c. tom. i. p. 237). The "ces animaux" leaves
the meaning of the authors doubtful.]

Audouin and Milne Edwards were the first to see the importance of the
bearing of a knowledge of the manner in which marine animals are
distributed in depth, on geology. They suggest that, by this means, it
will be possible to judge whether a fossiliferous stratum was formed upon
the shore of an ancient sea, and even to determine whether it was
deposited in shallower or deeper water on that shore; the association of
shells of animals which live in different zones of depth will prove that
the shells have been transported into the position in which they are
found; while, on the other hand, the absence of shells in a deposit will
not justify the conclusion that the waters in which it was formed were
devoid of animal inhabitants, inasmuch as they might have been only too
deep for habitation.

The new line of investigation thus opened by the French naturalists was
followed up by the Norwegian, Sars, in 1835, by Edward Forbes, in our own
country, in 1840,[4] and by Oersted, in Denmark, a few years later. The
genius of Forbes, combined with his extensive knowledge of botany,
invertebrate zoology, and geology, enabled him to do more than any of his
compeers, in bringing the importance of distribution in depth into
notice; and his researches in the Aegean Sea, and still more his
remarkable paper "On the Geological Relations of the existing Fauna and
Flora of the British Isles," published in 1846, in the first volume of
the "Memoirs of the Geological Survey of Great Britain," attracted
universal attention.

[Footnote 4: In the paper in the _Memoirs of the Survey_ cited further
on, Forbes writes:--

"In an essay 'On the Association of Mollusca on the British Coasts,
considered with reference to Pleistocene Geology,' printed in [the
_Edinburgh Academic Annual_ for] 1840, I described the mollusca, as
distributed on our shores and seas, in four great zones or regions,
usually denominated 'The Littoral zone,' 'The region of Laminariae,' 'The
region of Coral-lines,' and 'The region of Corals.' An extensive series
of researches, chiefly conducted by the members of the committee
appointed by the British Association to investigate the marine geology of
Britain by means of the dredge, have not invalidated this classification,