hern
continent, Gondwana Land, and has left numerous remains in South Africa.
We shall see that they are connected by many authorities with the origin
of the mammals. [*] The other branch, the Diapsids, are represented
to-day by the curiously primitive lizard of New Zealand, the tuatara
(Sphenodon, or Hatteria), of which I have seen specimens, nearly two
feet in length, that one did not care to approach too closely. The
Diapsids are chiefly interesting, however, as the reputed ancestors of
the colossal reptiles of the Jurassic age and the birds.

* These Synapsid reptiles are more commonly known as
Pareiasauria or Theromorpha.

The purified air of the Permian world favoured the reptiles' being
lung-breathers, but the cold would check their expansion for a time.
The reptile, it is important to remember' usually leaves its eggs to
be hatched by the natural warmth of the ground. But as the cold of the
Permian yielded to a genial climate and rich vegetation in the course of
the Triassic, the reptiles entered upon their memorable development. The
amphibia were now definitely ousted from their position of dominance.
The increase of the waters had at first favoured them, and we find more
than twenty genera, and some very large individuals, of the amphibia
in the Triassic. One of them, the Mastodonsaurus, had a head three feet
long and two feet wide. But the spread of the reptiles checked them, and
they shrank rapidly into the poor and defenceless tribe which we find
them in nature to-day.

To follow the prolific expansion of the reptiles in the semi-tropical
conditions of the Jurassic age is a task that even the highest
authorities approach with great diffidence. Science is not yet wholly
agreed in the classification of the vast numbers of remains which the
Mesozoic rocks have yielded, and the affinities of the various groups
are very uncertain. We cannot be content, however, merely to throw on
the screen, as it were, a few of the more quaint and monstrous types out
of the teeming Mesozoic population, and describe their proportions and
peculiarities. They fall into natural and intelligible groups or orders,
and their features are closely related to the differing regions of
the Jurassic world. While, therefore, we must abstain from drawing
up settled genealogical trees, we may, as we review in succession the
monsters of the land, the waters, and the air, glance at the most recent
and substantial conjectures of sc