e nearly five hundred miles,
they could not find its end. In the shallow water along its
shores, and on the islands rising but a few feet above the waves,
they saw all kinds of amphibians and sea-monsters. Many of these were
almost the exact reproduction in life of the giant plesiosaurs,
dinosaurs, and elasmosaurs, whose remains are preserved in the museums
on earth. The reptilian bodies of the elasmosaurs, seventy-five feet
in length, with the forked tongues, distended jaws and fangs of a
snake, were easily taken for the often described but probably mythical
sea-serpent, as partially coiled they occasionally raised their heads
twelve or fifteen feet.

"Man in his natural state," said Cortlandt, "would have but small
chance of surviving long among such neighbours. Buckland, I think,
once indulged in the jeu d'esprit of supposing an ichthyosaur lecturing
on the human skull. 'You will at once perceive,' said the lecturer,
'that the skull before us belonged to one of the lower order of
animals. The teeth are very insignificant, the power of the jaws
trifling, and altogether it seems wonderful how the creature could have
procured food.' Armed with modern weapons, and in this machine, we are,
of course, superior to the most powerful monster; but it is not likely
that, had man been so surrounded during the whole of his evolution, he
could have reached his present plane."

Notwithstanding the striking similarity of these creatures to their
terrestrial counterparts that existed on earth during its corresponding
period, there were some interesting modifications. The organs of
locomotion in the amphibians were more developed, while the eyes of all
were larger, the former being of course necessitated by the power of
gravity, and the latter by the greater distance from the sun.

"The adaptability and economy of Nature," said Cortlandt, "have always
amazed me. In the total blackness of the Kentucky Mammoth Cave, where
eyes would be of no use to the fishes, our common mother has given them
none; while if there is any light, though not as much as we are
accustomed to, she may be depended upon to rise to the occasion by
increasing the size of the pupil and the power of the eye. In the
development of the ambulatory muscles we again see her handiwork,
probably brought about through the 'survival of the fittest.' The
fishes and those wholly immersed need no increase in power, for, though
they weigh more than they wou