Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/244

150 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Jan. 13, by Conybeare to designate the Newer Red Sandstones of this country, seems to me to be very fit for this purpose; and in speaking of the Poikilitic period, I should like to make its earlier and later boundaries as hazy as possible, and to apply it exclusively to terrestrial conditions and to land and freshwater faunas, without prejudice to the limits in time of the marine conditions known as Permian and Triassic.

It does not appear to me that there is any necessary relation between the fauna of a given land and that of the seas of its shores. The land faunae of Britain and of Japan are wonderfully similar; their marine faunae are in many ways different. Identical marine shells are collected on the Mozambique coast and in the easternmost islands of the Pacific; while the faunae of the lands which lie within the same range of longitude are extraordinarily different. What now happens geographically to provinces in space, is good evidence as to what, in former times, may have happened to provinces in time; and an essentially identical land-fauna may have been contemporary with several successive marine faunae.

At present, our knowledge of the terrestrial faunae of past epochs is so slight, that no practical difficulty arises from using, as we do, sea-reckoning for land time; but I think it highly probable that, sooner or later, the inhabitants of the land will be found to have a history of their own,—mixed up with that of the sea, indeed, but independent of it, in some such relation as the histories of England and that of France.

If the terrestrial faunae which I thus propose to term Poikilitic, were, in the historical sense of the word, contemporaneous, it would appear to be highly probable that, at their epoch, as at the present day, animals were distributed in distinct geographical provinces. It cannot well be a matter of accident that, with such uniformity in general facies, there is such diversity in detail between the four faunae I have mentioned. And it is very interesting to remark that, just as at the present day, the Poikilitic fauna of India had distinct and independent relations, on the one hand, with that of Europe, and on the other with that of South Africa.

But I am disposed to think that there is a closer connexion than that of mere analogy between the geographical distribution of terrestrial animals in the Triassic epoch and that which obtains at the present day.

In the famous sandstones of the Connecticut valley, in North America, neither bones nor teeth have yet been discovered; but the foot-tracks show that either ornithoid Sauria, or true birds, or most probably both, existed in the Poikilitic period. Some of these bird-like creatures, such as the Brontozoum, were of gigantic size. They were associated with true reptiles, some of which, very probably, resembled the Hyperodapedon and Rhynchosaurus of western Europe.

With these facts before one's mind, how striking do the characters of the existing fauna of New Zealand appear! Its one characteristic reptile is Sphenodon, so extraordinarily similar to Hyperodapedon;