r estuary,
are abundantly fossiliferous. In some the fresh-water character of the
deposit is well marked: Cyprides are so exceedingly numerous in some of
the bands, that they impart to the stone an Oolitic appearance; while
others of a dark-colored limestone we see strewed over, like the oozy
bottom of a modern lake, with specimens of what seem Paludina, Cyclas,
and Planorbus. Some of the other shells are more equivocal: a Mytilus or
Modiola, which abounds in some of the bands, may have been either a sea
or a fresh-water shell; and a small oyster and Astarte seem decidedly
marine. Remains of fish are very abundant,--scales, plates, teeth,
ichthyodorulites, and in some instances entire ichthyolites. I saw, in
the collection of Mr. Duff, a small but very entire specimen of
_Lepidotus minor_, with the fins spread out on the limestone, as in an
anatomical preparation, and almost every plate and scale in its place.
Some of his specimens of ichthyodorulites, too, are exceedingly
beautiful, and of great size, resembling jaws thickly set with teeth,
the apparent teeth being mere knobs ranged along the concave edge of the
bone, the surface of which we see gracefully fluted and enamelled. What
most struck me, however, in glancing over the drawers of Mr. Duff, was
the character of the Ganoid scales of this deposit. The Ganoid order in
the days of the Weald was growing old; and two new orders,--the Ctenoid
and Cycloid,--were on the eve of taking its place in creation. Hitherto
it had comprised at least two-thirds of all the fish that had existed
ever since the period in which fish first began; and almost every Ganoid
fish had its own peculiar pattern of scale. But it would now seem as if
well nigh all the simpler patterns were exhausted, and as if, in order
to give the variety which nature loves, forms of the most eccentric
types had to be resorted to. With scarce any exception save that
furnished by the scales of the _Lepidotus minor_, which are plain
lozenge-shaped plates, thickly japanned, the forms are strangely complex
and irregular, easily expressible by the pencil, but beyond the reach of
the pen. The remains of reptiles have been found occasionally, though
rarely, in this outlier of the Weald,--the vertebra of a Plesiosaurus,
the femur of some Chelonian reptile, and a large fluted tooth, supposed
Saurian.

I would fain have visited some of the neighboring outliers of the
Oolite, but time did not permit. Mr. Duff's collectio