e conch shell appears to have been a favorite model,
especially in its modified form, Fig. 374, _a_ and _b_. The clam shell
is also imitated in _c_ and _d_. The more conventional forms of these
vessels are exceedingly interesting, as they point out the tendencies
and possibilities of modification. An instructive example illustrated
in _e_ has four groups of nodes, each, consisting of a large central
node with four or five smaller ones, surrounding it, set about the
rim, the conception being that of four shells joined in one vessel,
with the noded apexes turned outward and the bases inward.

A still more highly conventionalized form is shown in _f_. The cup
is unsymmetrical in outline, and has a few imperfect nodes near one
corner, but its resemblance to a shell would hardly be recognized by
one unacquainted with more realistic renderings of like subjects. In
_g_ we have an imitation of a shell cup placed within a plain cup.

[Illustrations: FIG. 374.--Clay vessels imitating shells.]

A very good illustration of this class of vessel is given in Fig. 375.
It is evidently intended to imitate a trimmed conch shell. The apex
and a few of the surrounding nodes are shown at the right, while the
base or spine forms a projecting lip at the left. A coil of clay forms
the apex. This is carried outward in a sinistral spiral to the noded
shoulder. We have here a suggestion of the origin of a favorite
decorative motive, the scroll, a clew, however, which the paucity of
examples makes it difficult to follow up satisfactorily.

[Illustration: FIG. 375.--Bowl imitating a modified conch shell.--1/3.]

Although we may not be able to arrive at any definite conclusion in
regard to the origin and significance of the practice of modeling
life forms in clay, we are certain of one thing, that it became an
important feature in the potter's art, and that in due course of time
the practice broke loose from the restraints of birth and tradition
and asserted its freedom in the production of any form that
superstition or fancy happened to select.

The artist probably did not follow nature with great accuracy in all
the details of species and varieties, but some definite model must
have been in view, in nearly all cases, and such characters as came
to be regarded as essential to that creature were never lost sight of,
consistency being a most notable characteristic of the art of a savage
or barbaric people.

[Illustration: FIG. 376.--Frog-shape