s content themselves with assigning
to any particular shell the too-comprehensive habitat of "the Indian
Ocean," and seldom discriminate between a specimen from Ceylon and one
from the Eastern Archipelago or Hindustan. In a very few instances,
Ceylon has been indicated with precision as the habitat of particular
shells, but even here the views of specific essentials adopted by modern
conchologists, and the subdivisions established in consequence, leave us
in doubt for which of the described forms the collective locality should
be retained.

Valuable notices of Ceylon shells are to be found in detached papers, in
periodicals, and in the scientific surveys of exploring voyages. The
authentic facts embodied in the monographs of REEVE, KUSTER, SOWERBY,
and KIENER, have greatly enlarged our knowledge of the marine testacea;
and the land and fresh-water mollusca have been similarly illustrated by
the contributions of BENSON and LAYARD to the _Annals of Natural
History_.

The dredge has been used, but only in a few insulated spots along the
coasts of Ceylon; European explorers have been rare; and the natives,
anxious only to secure the showy and saleable shells of the sea, have
neglected the less attractive ones of the land and the lakes. Hence Mr.
Hanley finds it necessary to premise that the list appended, although
the result of infinite labour and research, is less satisfactory than
could have been wished. "It is offered," he says, "with diffidence, not
pretending to the merit of completeness as a shell-fauna of the island,
but rather as a form, which the zeal of other collectors may hereafter
elaborate and fill up."

Looking at the little that has yet been done, compared with the vast and
almost untried field which invites explorers, an assiduous collector may
quadruple the species hitherto described. The minute shells especially
may be said to be unknown; a vigilant examination of the corals and
excrescences upon the spondyli and pearl-oysters would signally increase
our knowledge of the Rissoae, Chemnitziae, and other perforating testacea,
whilst the dredge from the deep water will astonish the amateur by the
wholly new forms it can scarcely fail to display.

* * * * *

_List of Ceylon Shells._

The arrangement here adopted is a modified Lamarckian one, very similar
to that used by Reeve and Sowerby, and by Mr. HANLEY, in his
_Illustrated Catalogue of Recent Shells_.[1]

[Footnote