In the first place, Professor Owen pointed out that the sea-saurians of the secondary period have been replaced in the tertiary and present seas by the whales and allied races. No whales are found in the secondary strata, no saurians in the tertiary. “It seems to me less probable,” he says, “that no part of the carcase of such reptiles should have ever been discovered in a recent unfossilized state, than that men should have been deceived by a cursory view of a partly submerged and rapidly moving animal which might only be strange to themselves. In other words, I regard the negative evidence from the utter absence of any of the recent remains of great sea-serpents, krakens, or enaliosauria, as stronger against their actual existence, than the positive statements which have hitherto weighed with the public mind in favour of their existence. A larger body of evidence from eye-witnesses might be got together in proof of ghosts than of the sea-serpent.” To this it has been replied that genera are now known to exist, as the _Chimæra_, the long-necked river tortoise, and the iguana, which are closely related to forms which existed in the secondary era, while no traces have been found of them in any of the intermediate or tertiary strata. The chimæra is a case precisely analogous to the supposed case of the enaliosaurus, for the chimæra is but rarely seen, like the supposed enaliosaurus, is found in the same and absent from the same fossiliferous strata. Agassiz is quoted in the _Zoologist_, page 2395, as saying that it would be in precise conformity with analogy that such an animal as the enaliosaurus should exist in the American seas, as he had found numerous instances in which the fossil forms of the Old World were represented by living types in the New. In close conformity with this opinion is a statement made by Captain the Hon. George Hope, that when in the British ship _Fly_, in the Gulf of California, the sea being perfectly calm and transparent, he saw at the bottom a large marine animal, with the head and general figure of an alligator, but the neck much longer, and with four large paddles instead of legs. Here, then, unless this officer was altogether deceived, which seems quite unlikely under the circumstances, was a veritable enaliosaurus, though of a far smaller species, probably, than the creature mistaken for a sea-serpent.