beak, and habits or violence and
voracity; and for preference, the shortness of the legs, and other
circumstances, may be held to claim for the Stonesfield fossil a
more than fanciful similitude to the groups of Cormorants, and
other marine divers, which constitute an effective part of the
picturesque army of robbers of the sea."

Another extraordinary and interesting group of the Mesozoic Reptiles
is constituted by the _Deinosauria_, comprising a series of mostly
gigantic forms, which range from the Trias to the Chalk. All the
"Deinosaurs" are possessed of the two pairs of limbs proper to
Vertebrate animals, and these organs are in the main adapted for
walking on the dry land. Thus, whilst the Mesozoic seas swarmed
with the huge Ichthyosaurs and Plesiosaurs, and whilst the air
was tenanted by the Dragon-like Pterosaurs, the land-surfaces of
the Secondary period were peopled by numerous forms of Deinosaurs,
some of them of even more gigantic dimensions than their marine
brethren. The limbs of the _Deinosaurs_ are, as just said, adapted
for progression on the land; but in some cases, at any rate, the
hind-limbs were much longer and stronger than the fore-limbs;
and there seems to be no reason to doubt that many of these forms
possessed the power of walking, temporarily or permanently, on their
hind-legs, thus presenting a singular resemblance to Birds. Some
very curious and striking points connected with the structure of
the skeleton have also been shown to connect these strange Reptiles
with the true Birds; and such high authorities as Professors Huxley
and Cope are of opinion that the Deinosaurs are distinctly related
to this class, being in some respects intermediate between the
proper Reptiles and the great wingless Birds, like the Ostrich
and Cassowary. On the other hand, Professor Owen has shown that the
Deinosaurs possess some weighty points of relationship with the
so-called "Pachydermatous" Quadrupeds, such as the Rhinoceros and
Hippopotamus. The most important Jurassic genera of _Deinosauria_
are _Megalosaurus_ and _Cetiosaurus_, both of which extend their
range into the Cretaceous period, in which flourished, as we
shall see, some other well-known members of this order.

[Illustration: Fig. 180.--Skull of _Megalosaurus_, on a scale
one-tenth of nature. Restored. (After Professor Phillips.)]

_Megalosaurus_ attained gigantic dimensions, its thigh and shank
bones measuring each about three feet in length, an