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extend so far south. We have here remains of Equus, Bos, Antilope, Hippopotamus, Elephas, Rhinoceros, Ursus, Canis, and Hyæna, together with Phacochorus, an African type of swine which has not occurred in the European deposits.

It is perhaps to the earlier portion of this period that the Merycotherium of the Siberian drift belongs. This was an animal related to the living camel, thus supporting the view that the Camelidae are essentially denizens of the extra-tropical zone.

PLIOCENE PERIOD.

Primates.We here first meet with evidence of the existence of monkeys in Central Europe. Species of Macacus have left remains not only in the Newer Pliocene of the Val d'Arno in Italy, but in beds of the same age at Grays in Essex ; while Semnopithecus and Cercopithecus, genera now confined to the Oriental and Ethiopian regions respectively, have been found in the Pliocene deposits of the South of France and Italy.

Carnivora.—Most of the genera which occurred in the Post Pliocene are found here also, and many of the same species. Few new forms appear, except Hyænarctos, a large bear with characters approaching the hyænas, and Pristiphoca, a new form of seal, both from the Older Pliocene of France; and Galecynus, a foxlike animal intermediate between Canis and Viverra, from the Pliocene of Eninghen in Switzerland.

Cetacea.-Species of Balæna, Physeter, and Delphinus occur in the Older Pliocene of England and France, and with these the remains of many extinct forms, Balanodon and Hoplocetus (Balænidæ); Belemnoziphius and Choneziphius (Hyperoodontidæ), and Halitherium, an extinct form of the next order-Sirenia, now confined to the tropics, although the recently extinct Rytina of the N. W. Pacific shows that it is also adapted for temperate climates.

Ungulata.—The Pliocene deposits are not very rich in this order. The horses (Equide) are represented by the genus Equus ; and here we first meet with Hipparion, in which small lateral toes appear. Both genera occur in British deposits of this age.

A more interesting fact for us is the occurrence of the genus Tapirus in the Newer Pliocene of France and in the older beds of both France and England, since this genus is now isolated in the remotest parts of the eastern and western tropics. The genera Rhinoceros, Hippopotamus, and Sus, occur here as in the preceding epoch.

We next come to the deer genus (Cervus), which appears to have been at its maximum in this period, no less than eight species occurring in the Norwich Crag, and Forest-beds. Among the Bovidæ, the antelopes, ox, and bison, are the only forms represented here, as in the Post-Pliocene period. Passing on to the Proboscidea, we find three species of elephants and two of Mastodon preserved in European beds of this period, all distinct from those of Post-Pliocene times.

Rodentia.-In this order we find representatives of many living European forms; as Cricetus (hamster), Arvicola (vole), Castor (beaver), Arctomys (marmot), Hystrix (porcupine), Lepus (hare), and Lagomys (pika); and a few that are extinct, the most important being Chalicomys, allied to the beaver ; and Issiodromys, said to come nearest to the remarkable Pedetes of South Africa, both found in the Pliocene formations of France.

General Conclusions as to Pliocene and Post-Pliocene Faunas of Europe.—This completes the series of fossil forms of the Pliocene deposits of Europe. They show us that the presence of numerous large carnivora and ungulates (now almost wholly tropical) in the Post-Pliocene period, was due to no exceptional or temporary cause, but was the result of a natural succession from similar races which had inhabited the same countries for long preceding ages. In order to understand the vast periods of time covered by the Pliocene and Post-Pliocene formations, the works of Sir Charles Lyell must be studied. We shall then come to see, that the present condition of the fauna of Europe is wholly new and exceptional. For a long succession of ages, various forms of monkeys, hyænas, lions, horses, hipparions, tapirs, rhinoceroses, hippopotami, elephants, mastodons, deer, and antelopes, together

with almost all the forms now living, produced a rich and varied fauna such as we now see only in the open country of tropical Africa. During all this period we have no reason to believe that the climate or other physical conditions of Europe were more favourable to the existence of these animals than now. We must look upon them, therefore, as true indigenes of the country, and their comparatively recent extinction or banishment as a remarkable phenomenon for which there must have been some adequate

What this cause was we can only conjecture ; but it seems most probable that it was due to the combined action of the Glacial period, and the subsidence of large areas of land once connecting Europe with Africa. The existence, in the small island of Malta, of no less than three extinct species of elephant (two of very small stature), of a gigantic dormouse, an extinct hippopotamus, and other mammalia, together with the occurrence of remains of hippopotamus in the caves of Gibraltar, indicate very clearly that during the Pliocene epoch, and perhaps during a considerable part of the Post-Pliocene, a connection existed between South Europe and North Africa in at least these two localities. At the same time we have every reason to believe that Britain was united to the Continent, what is now the German Ocean constituting a great river-valley. During the height of the Glacial epoch, these large animals would probably retire into this Mediterranean land and into North Africa, making annual migrations northwards during the summer. But as the connecting land sank and became narrower and narrower, the migrating herds would diminish, and at last cease altogether; and when the glacial cold had passed away would be altogether prevented from returning to their former haunts. .

MIOCENE PERIOD.

We now come to a period which was wonderfully rich in all forms of life, and of which the geological record is exceptionally complete. Various lacustrine, estuarine, and other deposits in Europe, North India, and North America, have furnished such a

vast number of remains of extinct mammalia, as to solve many zoological problems, and to throw great light on the early distribution and centres of dispersal of various groups of animals. In order to show the bearing of these remains on our special subject, we will first give an account of the extinct fauna of Greece, of the Upper Miocene period; since this, being nearest to Africa and Asia, best exhibits the relations of the old European fauna to those countries. We shall then pass to the Miocene fauna of France and Central Europe; and conclude with the remarkable Siwalik and other Indian extinct faunas, which throw an additional light on the early history of the animal life of the great old-world continents.

Extinct Animals of Greece. These are from the Upper Miocene deposits at Pikermi, near Athens, and were collected by M. Gaudry a few years ago. They comprise ten living and eighteen extinct genera of mammalia, with a few birds and reptiles.

Primates. These are represented by Mesopithecus, a genus believed to be intermediate between the two Indian genera of monkeys, Semnopithecus and Macacus.

Carnivora.—These were abundant. Of Felis there were four species, ranging from the size of a cat to that of a jaguar, a large hyæna, and a large weasel (Mustela). Besides these there were the huge Machairodus, larger than any existing lion or tiger, and with enormously developed canine teeth ; Hyænictis and Lycæna, extinct forms of Hyænidæ; Thalassictis=Ictitherium, an extinct genus of Viverridæ but with resemblances to the hyænas, represented by three species, some of which were larger than any existing Viverridæ; Promephytis, an extinct form of Mustelidæ, having resemblances to the European marten, to the otters, and to the S. African Zorilla ; and lastly, Simocyon, an extraordinary carnivore of the size of a small panther, but having the canines of a cat, the molars of a dog, and the jaws shaped like those of a bear.

Ungulata.—These are numerous and very interesting. The Equidæ are represented by the three-toed Hipparion, which con

tinued to exist till the Older Pliocene period. There are three large species of Rhinoceros, as well as a species of the extinct genus Leptodon of smaller size. Remains of a very large wild boar (Sus) were found. Very interesting is the occurrence of a species of giraffe (Camelopardalis) as tall as the African species but more slender; and also an extinct genus Helladotherium, not quite so tall as the giraffe but much more robust, and showing some approach to the Antilopidæ in its dentition. Antelopes were abundant, ranging from the size of the gazelle to that o the largest living species. Three or four seem referable to living genera, but the majority are of extinct types, and are classed in the genera Palæotragus, Palæoryc, Tragocerus, and Palæoreas ; while Dremotherium is an ancient generalized form of Cervidæ

or deer.

Proboscidea.- These are represented by two species of Mastodon, and two of Dinotherium, an extraordinary extinct form supposed to be, to some extent, intermediate between the elephants and the aquatic manatees (Sirenia.)

Rodentia.--This order is represented by a species of Hystrix, larger than living porcupines.

Edentata.—This order, now almost confined to South America, was represented in the Miocene period by several European species. Ancylotherium and Macrotherium, belonging to an extinct family but remotely allied to the African ant-bear (Orycteropus), occur in Greece.

Birds.—Species of Phasianus and Gallus were found; the latter especially interesting as being now confined to India.

Reptiles.—These are few and unimportant, consisting of a tortoise (Testudo) and a large lizard allied to Varanus.

Summary of the Miocene Fauna of Greece. --Although we cannot consider that the preceding enumeration gives us by any means a complete view of the actual inhabitants of this part of Europe during the later portion of the Miocene period, we yet obtain some important information. The resemblance that appeared in the Pliocene fauna of Europe, to that of the open country of tropical Africa, is now still more remarkable. We

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