In Greece, at Pikerme, near Athens, there occurs a celebrated deposit of Upper Miocene age, well known to palaeontologists through the researches of M. M. Wagner, Roth, and Gaudry upon the numerous Mammalia which it contains.  In Italy, also, strata of both Lower and Upper Miocene age are well developed in the neighbourhood of Turin.

In the Siwalik Hills, in India, at the southern foot of the Himalayas, occurs a series of Upper Miocene strata, which have become widely celebrated through the researches of Dr Falconer and Sir Proby Cautley upon the numerous remains of Mammals and Reptiles which they contain.  Beds of corresponding age, with similar fossils, are known to occur in the island of Perim in the Gulf of Cambay.

Lastly, Miocene deposits are found in North America, in New Jersey, Maryland, Virginia, Missouri, California, Oregon, &c., attaining a thickness of 1500 feet or more.  They consist principally of clays, sands, and sandstones, sometimes of marine and sometimes of fresh-water origin.  Near Richmond, in Virginia, there occurs a remarkable stratum, wrongly called “Infusorial Earth,” which is occasionally 30 feet in thickness, and consists almost wholly of the siliceous envelopes of certain low forms of plants (Diatoms), along with the spicules of Sponges and other siliceous organisms (see fig. 16).  The White River Group of Hayden occurs in the Upper Missouri region, and is largely exposed over the barren and desolate district known as the “Mauvaises Terres.”  They have a thickness of 1000 feet or more, and contain numerous remains of Mammals.  They are of lacustrine origin, and are believed to be of the age of the Lower Miocene.  Upon the whole, about from 15 to 30 per cent of the Mollusca of the American Miocene are identical with existing species.

In addition to the regions previously enumerated, Miocene strata are known to be developed in Greenland, Iceland, Spitzbergen, and in other areas of less importance.

The life of the Miocene period is extremely abundant, and, from the nature of the deposits of this age, also extremely varied in its character.  The marine beds of the formation have yielded numerous remains of both Vertebrate and Invertebrate sea-animals; whilst the fresh-water deposits contain the skeletons of such shells, fishes, &c., as now inhabit rivers or lakes.  Both the marine and the lacustrine beds have been shown to contain an enormous number of plants, the latter more particularly; whilst the Brown Coals of the formation are made up of vegetable matter little altered from its original condition.  The remains of air-breathing animals, such as Insects, Reptiles, Birds, and Mammals, are also abundantly found, more especially in the fresh-water beds.