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It appears that of more than fifty species of these foraminifera described by D'Archiac, one or two species only are found in other tertiary formations whether of older or newer date. Nummulites intermedia, a Middle Eocene form, ascends into the Lower Miocene, but it seems doubtful whether any species descends to the level of the London clay, still less to the Argile plastique or Woolwich beds.
No less than 844 species are reckoned by Heer from the Oeningen beds alone, the number of specimens which he has examined being 5080. The entire list of Swiss species from the Upper and Lower Miocene together amount to 1322.
The Zeuglodons from Eocene down to Pliocene, the Dolphins in the Pliocene, and the Ziphoids Catodontidae, and Balaenidae in the Pliocene, are all fully developed forms, with no intermediate species. Eohippus Lower Eocene of America; fore-feet have four toes and a rudimentary thumb or pollex. 2. Anchitherium Eocene and Lower Miocene; three toes, but 2 and 4 are diminutive. 4.
The living shells of Madeira and Porto Santo are in like manner those of a temperate climate, although in great part differing specifically from those of Mogador. In the Canaries, especially in the Grand Canary, the same marine Upper Miocene formation is found.
In Secondary or even Eocene or Miocene times, Timor and Australia may have been connected; but if so, all record of such a union has been lost by subsequent submergence, and in accounting for the present land-inhabitants of any country we have only to consider those changes which have occurred since its last elevation above the waters since such last elevation, I feel confident that Timor has not formed part of Australia.
For the sake of clearness and brevity, I proposed to give short technical names to these sets of strata, or the periods to which they respectively belonged. I called the first or oldest of them Eocene, the second Miocene, and the third Pliocene.
The mountains of Sinai were islands in this ocean, which had a very wide range over parts of Asia, Africa, and Europe. But at the commencement of the succeeding Miocene stage the crust was subjected to lateral contraction, owing to which the ocean bed was upraised.
Thus, assuming that the accumulation of polar ice since the Miocene epoch has only been sufficient to produce ten times the effect of a coat of ice one foot thick, we shall have an accelerating cause which covers all the loss from tidal action, and leaves a balance of 4/5 a second per annum in the way of acceleration.
But it is very remarkable that while the Miocene fauna of the Arctogaeal province, as a whole, is of the same character as the existing fauna of the same province, as a whole, the component elements of the fauna were differently associated.
These pervious sands, interbedded with the lava, become the aquifers of artesian wells. In places the lavas rest on extensive lake deposits, one thousand feet deep, and Miocene in age as their fossils prove. It is to the middle Tertiary, then, that the earliest flows and the largest bulk of the great inundation belong.
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