none of the Old World. It was the Megalosaurus of America.

Another of the gigantic reptiles which carried on a war of extermination upon the fields destined to be ensanguined by the battles of Trenton and Brandywine was the Hadrosaur (Hadrosaurus Foulki, Leidy). The visitor to the museum of the Academy of Sciences of Philadelphia can not fail to be impressed by the skeleton of one of these monsters mounted in the attitude of browsing from a cycadeous tree. This piece of work is by the eminent restorer of extinct animals, B. Waterhouse Hawkins, Esq., of London, to whose courtesy I am indebted for the photographic view which adorns the opposite page (Fig. 76). The Hadrosaur attained the length of thirty feet. The femur or thighbone was sometimes five feet in

length, exceeding by more than a foot the maximum length of the femur of the Iguanodon of England, the largest of the hitherto known land reptiles. The fore limbs were less than half the length of the hind limbs. The form of the feet and toes shows that they were poorly adapted for swimming. In its habitual attitude it rested, like the kangaroo, upon its enormous hind limbs and tail. With its supple anterior extremities it reached upward to the foliage of the tree destined to afford it food, and drew the branches down within the reach of the grinding jaws. Not unlikely this land-monster walked at times upon its And feet, while the ponderous tail dragged behind.

Thus, on both continents, gigantic reptes i

swayed the sceptre over the entire anima. create

time
bu

195

their empire was approaching its end. One of the tr

of Nature, through which new annexations of at the
continent were ef-
fected, ushered in
the closing stage
of Mesozoic Time.
The conditions of
life were changed;
all the peculiar
types whose histo-
ry we have traced
dropped out of ex-
istence, and mam-
mals assumed the
reins of empire.
Turtles received
accessions of num-
bers, and serpents
now first uncoiled
their sinuous
lengths, while ba-
trachians made the
bayous and marsh-

es resonant with

the varied piping of a myriad voices.

Fig. 76. The Hadrosaurus.

Among the latter a salamander, known as Andrias Scheuchzeri, has attracted most attention, in consequence of having for a long time been regarded as the skeleton of a man, who thus, by the fossilization of his remains, was supposed to attest the reality of the Deluge of Noah.

Such is a hasty glance at the Age of Reptiles. Success-
I

Then, but the vhe xtent of treat 3 E Fas not bectekt VI &enge unga wrile luring the lumin Vet in the site de Waden the 3mm le us maintained for in fra spentes of Dinosaurs freen e "vate Crocodilians, d for sixy feet in length, to say nothing of the prob

* feet in length, toa Al Fualiosaurs tot Porosaurs and Turt.

་ ་་

merous species whose famains have as yet esservation. These successime swells in the stream are convenient standpoints from which to ssive development of organic existence. reptiles, like that of fishes, presents some Atonal features, which have a most imNg upon the question of development," Teking a font rank among the questions of the For those exposes of the case are reserved for future

པ་ ་ ་ ་

་

*

m

a

CHAPTER XVII.

THE GEOGRAPHY OF THE EMPIRE OF REPTILES.

NONTINENTS have been developed, like organisms,

CONTI

from their primeval germs. Geologic force, like vital force, operates always toward the accomplishment of some definite end; and, notwithstanding its vicissitudes, there is little difficulty in perceiving how every phenomenon of one age has been contemplated and ministered to by the events of all preceding ages. The American Continent is not a single upthrow of volcanic force, but a gradual growth, beginning before the creation of the first animals and plants, and proceeding by a certain method through all the subsequent ages even to the present, and receiving from time. to time such progressively improved existences as its physical circumstances permitted. At first it was an angulated ridge of land in the centre of the present continental area (Fig. 20). Then, by successive upheavals, belts of increment were added on the southeast and southwest, till the ancient ocean has been narrowed to its present limits. Like the exogenous growth of an oak, the increase has been always upon the outside. So the vast continent has been built up and configurated in accordance with a method as definite as that which has shaped the globe itself.

The empire of molluscs saw the greater portion of the continent the bed of the sea. The reign of fishes witnessed the emergence of only the extreme northeastern and northwestern portions of the United States (Fig. 55). In the earlier part of the reign of reptiles New England was a peninsula hemmed in by the broad estuary of the St. Law

ive phases of animal life have swept like waves over the surface of our planet, but none has been more striking or more real than that which was dominant through Mesozoic time. Throughout the whole extent of Great Britain there has not been known a single large reptile during the human era; yet in the single era of the Wealden the British dominions maintained four or five species of Dinosaurs fifteen to twenty feet in length, ten or twelve Crocodilians, Lacertians, and Enaliosaurs ten to fifty or sixty feet in length, besides Pterosaurs and Turtles, to say nothing of the probably numerous species whose fossil remains have as yet escaped observation. These successive swells in the stream of animal life are convenient stand-points from which to note the progressive development of organic existence. The history of reptiles, like that of fishes, presents some remarkable exceptional features, which have a most important bearing upon the question of "development," which is taking a front rank among the questions of the age. But these aspects of the case are reserved for future consideration.