we know, in consequence, that the monstrosities did not appear _early_, but _late_, and that the progress of the race as a whole, though it still retains not a few of the higher forms, has been a progress, not of development from the low to the high, but of degradation from the high to the low. The reader may mark for himself, in the flounder, plaice, halibut, or turbot,—fishes of a family of which there appears no trace in the earlier periods,—an extreme example of the degradation of distortion superadded to that of displacement. At a first glance the _limbs_ seem but to exhibit merely the amount of natural misarrangement and misorder common to the _Acanthopterygii_ and _Sub-brachiati_;—the base of the pectorals are stuck on to the head, and the base of the ventrals attached to that of the pectorals. From the circumstance, however, that the creature is twisted half round and laid on its side, we find that at least one of the pairs of double fins—the pectorals—perform the part of single fins,—one projecting from the animal’s superior, the other from its inferior side, in the way the anal and dorsal fins project from the upper and under surfaces of other fishes; while its real dorsal and anal fins, both developed very largely, and—in order to preserve its balance—in about an equal degree, and wonderfully correspondent in form, perform, from their lateral position, the functions of single fins. Indeed, at a first glance they seem the analogues of the largely-developed pectorals of a very different family of flat fishes,—the Rays. It would appear as if single and double fins, by some such mutual agreement as that which, according to the old ballad, took place between the churl of Auchtermuchty and his wife, had agreed to exchange callings, and perform each the work of the other. The tail, too, possesses, in consequence of the twist, not the vertical position of other fish-tails, but is spread out horizontally, like the tails of the cetacea. It is however, in the head of the flounder and its cogeners that we find the more extraordinary distortions exemplified. In order to accommodate it to the general twist, which rendered lateral what in other fishes is dorsal and abdominal, and dorsal and abdominal what in other fishes is lateral, one half its features had to be twisted to the one side, and the other half to the other. The face and cranium have undergone such a change as that which the human face and cranium would undergo, were the eyes to be drawn towards the left ear, and the mouth towards the right. The skull, in consequence, exhibits, in its fixed bones, a strange Cyclopean character, unique among the families of creation: it has its one well-marked eye orbit opening, like that of Polyphemus, direct in the middle of the fore part of its head; while the other, external to the cranium altogether, we find placed among the free bones, directly over the maxillaries. And the wry mouth—twisted in