The usual length of the cachalot or sperm whale is about 70 feet, and its girth about 50 feet. If we assign to the unfortunate whale which was captured on this occasion, a length of only 50 feet, and a girth of only 35 feet, we should still have for the entire length of the supposed serpent about 100 feet. This can hardly exceed the truth, since the three whales are called large sperm whales. With a length of 100 feet and a girth of about 9 feet, however, a serpent would have no chance in an attempt to capture a sperm whale 50 feet long and 35 feet in girth, for the simple reason that the whale would be a good deal heavier than its opponent. In a contest in open sea, where one animal seeks to capture another bodily, weight is all-important. We can hardly suppose the whale could be so compassed by the coils of his enemy as to be rendered powerless; in fact, the contest lasted fifteen minutes, during the whole of which time the so-called serpent was whirling its victim round, though more massive than itself, through the water. On the whole, it seems reasonable to conclude—in fact, the opinion is almost forced upon us—that besides the serpentine portion of its bulk, which was revealed to view, the creature, thus whirling round a large sperm whale, had a massive concealed body, provided with propelling paddles of enormous power. _These_ were at work all the time the struggle went on, enabling the creature to whirl round its enemy easily, whereas a serpentine form, with two-thirds of its length, at least, coiled close round another body, would have had no propulsive power left, or very little, in the remaining 30 feet of its length, including both the head and tail ends beyond the coils. Such a creature as an enaliosaurus _could_ no doubt have done what a serpent of twice the supposed length would have attempted in vain—viz., dragged down into the depths of the sea the mighty bulk of a cachalot whale. When all the evidence is carefully weighed, we appear led to the conclusion that at least one large marine animal exists which has not as yet been classified among the known species of the present era. It would appear that this animal has certainly a serpentine neck, and a head small compared with its body, but large compared with the diameter of the neck. It is probably an air-breather and warm-blooded, and certainly carnivorous. Its propulsive power is great and apparently independent of undulations of its body, wherefore it presumably has powerful concealed paddles. All these circumstances correspond with the belief that it is a modern representative of the long-neck plesiosaurians of the great secondary or mesozoic era, a member of that strange family of animals whose figure has been compared to that which would be formed by drawing a serpent through the body of a sea-turtle. Against this view sundry objections have been raised, which must now be briefly considered.