true _Pinus_ appears in the Purbecks and a _Juglans_ in the
Chalk; while, from the Bagshot Sands, a _Banksia_, the wood of which is
not distinguishable from that of species now living in Australia, had
been obtained.

Turning to the animal kingdom, he affirmed the tabulate corals of the
Silurian rocks to be wonderfully like those which now exist; while even
the families of the Aporosa were all represented in the older Mesozoic
rocks.

Among the Mollusca similar facts were adduced. Let it be borne in mind
that _Avicula_, _Mytilus_, _Chiton_, _Natica_, _Patella_, _Trochus_,
_Discina_, _Orbicula_, _Lingula_, _Rhynchonella_, and _Nautilus_, all of
which are existing _genera_, are given without a doubt as Silurian in
the last edition of "Siluria;" while the highest forms of the highest
Cephalopods are represented in the Lias by a genus, _Belemnoteuthis_,
which presents the closest relation to the existing _Loligo_.

The two highest groups of the Annulosa, the Insecta and the Arachnida,
are represented in the Coal, either by existing genera, or by forms
differing from existing genera in quite minor peculiarities.

Turning to the Vertebrata, the only palaeozoic Elasmobranch Fish of which
we have any complete knowledge is the Devonian and Carboniferous
_Pleuracanthus_, which differs no more from existing Sharks than these
do from one another.

Again, vast as is the number of undoubtedly Ganoid fossil Fishes, and
great as is their range in time, a large mass of evidence has recently
been adduced to show that almost all those respecting which we possess
sufficient information, are referable to the same sub-ordinal groups as
the existing _Lepidosteus_, _Polypterus_, and Sturgeon; and that a
singular relation obtains between the older and the younger Fishes; the
former, the Devonian Ganoids, being almost all members of the same
sub-order as _Polypterus_, while the Mesozoic Ganoids are almost all
similarly allied to _Lepidosteus_.[37]

Again, what can be more remarkable than the singular constancy of
structure preserved throughout a vast period of time by the family of
the Pycnodonts and by that of the true Coelacanths: the former
persisting, with but insignificant modifications, from the Carboniferous
to the Tertiary rocks, inclusive; the latter existing, with still less
change, from the Carboniferous rocks to the Chalk, inclusive?

Among Reptiles, the highest living group, that of the Crocodilia, is
represented, at the ear