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MATHEMATICAL ILLUSTRATIONS.

II. Arithmetical Logarithms; Nature and Power

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VII.

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VIII.

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LI.

LII. The Eye, considered as an Optical Instrument.. 393

LESSONS IN READING AND ELOCUTION.

V. The Dash; Hyphen; Ellipsis ..... VI. The Apostrophe; Quotation Mark; Diæresis.. Analysis of the Voice; Quality of the Voice; Smoothness of the Voice; Versatility...... Distinct Articulation; Correct Pronunciation; True Time

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IX.

Appropriate Pauses; Right Emphasis

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Correct Inflections

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Exercises on Inflections ...........................

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XII.

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XIII.

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XIV.

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Rules on Expressive Tone; Appropriate Modulation; Promiscuous Exercises: Antiquity of Freedom; Pope and Dryden....... Promiscuous Exercises: the Puritans; Universal Decay; Eternity of God The Upright Lawyer; Human Culture; American Eagle; Memory; Old Ironsides...... 229 Interesting Adventure; Thoughts on Politeness; Ode on Art; GOD; Niagara Education of Females; Custom of Whitewashing; Child of the Tomb; Love and Fame Poetry; Causes of War; Foundation of National Character; Success of the Gospel; Power of the Soul; Hymn of Nature..... Woman; Tread-mill Song; Wouter Van Twiller; Palmyra

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XXI.

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Transmission of

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XXXIII. Expansion of Solids

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Man (Poetry)

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XXXIV. Expansion of Liquids

Ode on War

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Follow Me (Poetry)

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University of London

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Literary Composition

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CORRESPONDENCE.

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LESSONS IN GEOLOGY.-No. LI.

BY THOS. W. JENKYN, D.D., F.R.G.S., F.G.S., &c.

CHAPTER V.

THE CLASSIFICATION OF ROCKS.
SECTION IV.

(Continued from page 316, Vol. IV.)

ON THE TERTIARIES.

II. ON THE FOSSIL REMAINS OF THE TERTIARIES.

ALL the beds of the tertiary rocks have every appearance of having been deposited in a shallow sea, not far from coast lines, with much regularity, and in the course of many ages, The earlier beds are very extensive, and consist of rolled pebbles produced by the rubbing and wearing down of the chalk flints, and perhaps of fragments of hornblende and primitive rocks, scattered over a shallow sea-bottom. It is otherwise impossible to account for the immense beds of sand

found in the tertiaries.

To enable you to derive intellectual advantage from this lesson on the plants and animals of the tertiaries, your mind must keep firm hold of the following principles: 1. The term "tertiary" implies a "secondary" system of rocks as already in existence. The highest and newest of

these is the chalk,

2. The "secondary" beds may have formed either the bottoms of seas, or islands and mainlands, for many ages before the tertiaries began to be deposited.

3. During this interval, all the districts that now form the great plains of Europe were covered by the sea.

4. Most of the European land of that epoch lay chiefly from east to west, and extended far into the Atlantic, connecting the land now called England and Ireland not only with Spain, but also with the islands to the west of Africa.

6. At that time the Pyrenees, the Alps, Apennines, the Grecian Mountains, the Caucasus, the Carpathians, etc., formed a chain of islands in the open sea.

6. Things continued long in this tranquil state until a volcanic power threw up the Wealden of Kent and Sussex, and a gradual upheaval of the land took place, and the aforesaid islands rose gradually higher and higher above the ocean, and consequently more land was formed.

7. As those vast islands rose, the sea would dash against their sides, dislodge fragments from their cliffs, which they would roll smooth, wear down, until they constituted the beds of gravel which now cover the chalk in some places.

2. The shores of these islands and mainlands were low and swanoy, and large rivers brought down the mud and sand to form what is now the south-east of England, and also the formations about Brussels.

9. The sees were tenanted by animals like the shark, and by fishes of the tribes now found in warm latitudes, and by large shell-fish that could live either in salt, or in brackish,

Water.

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which took place during the tertiary epoch will explain the inclination or dip which mark the strata in some localities. The scooping or denuding action of the ocean upon the chalk beds will explain the hollows or the basins in which the tertiary formations rest.

VEGETATION.

In the basins scooped by denudation in the chalk, and which are now called the Basins of London, Hampshire, the Isle of Wight, and Paris, the Eocene beds always consist of a coarse pebbly gravel, at first spread pretty uniformly over the whole tract; but afterwards, when the and became more elevated, and consequently the rising rocks yielding different kinds of detritus, its character altered. If you imagine cliffs of rocks of different characters, thus gradually rising, and being constantly acted upon by the waves of the sea or by running water, and this water-action taking place in circumstances of great diversity, you will come by the facts which will enable you to account for the coarse limestones of Paris, the plastic clay of London, the marly clays of Brussels, the silicious or flinty formations from the warm springs in Auvergne in Central France, and for the various limestones of the Greek Islands. That the vegetation of the first tertiary land, or the Eocene, was very luxuriant, is proved by the fragments of wood and the fruits of trees which are found fossil in rich abundance in the Isle of Sheppey at the mouth of the Thames. These fossil woods are very great in number and very rich in variety. Even in the Isle of Sheppey alone, several hundred species have been discovered, all of them differing much from existing plants, though they are closely allied to some which are now found growing in warm climates. There is a large preponderance of a species allied to the palms, something like a kind between the cocoa-nut and the screw pine or Pandanus, which are so well known in tropical climates. There are others of the Nipa family, which now luxuriate in Japan, and in the Spice Islands.

The fossil wood of these trees is often found to have been pierced, and almost destroyed, by an extinct kind of Teredo, before it had been deposited in the mud. Sometimes the wood presents nothing but cavities, which had been left by these animals, and which were afterwards filled up with carbonate of

lime.

SHELLS.

The tertiary beds abound in shell animals, both univalve, having but one shell like the snail; or bivalve, having two shells like the oyster or cockle. The bed called the London clay is full of.the remains of crabs and lobsters, some of which are very perfect. One of the most remarkable groups amid these tertiaries, is a species of foraminiferous shell, called the nummulite on account of its resemblance to a small piece of money. The fossil remains of this shell-fish are so incredibly abundant in some localities, as that rocks of enormous size are entirely made up of them. The tertiary shells bear, for the most part, a considerable analogy to those which exist at present, as will be seen in Fig. 1.

Our engraving is only intended to represent a few specimens of the tertiary shells, to show their usual appearance and character. The entire species, as already determined by naturalists, amount to nearly three thousand. Some of the tertiary strata are almost entirely composed of shelly remains in a broken and crushed state, and many sandy seams in the clayey beds consist of shell dust. In some places the shells are pre

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served in their perfect forms. Some of them are the shells of animals that lived in the sea. As the Cypræa inilata or the Cowry, 20-the Fusus, 26-the Cerithium Lamellosum, 14the Pleurotoma, 17-the Lucina, 3-the Ampullaria, 22-the Venericardia, 7-the Mitra, 19-the Rostellaria, 23. In the Red Crag of Suffolk, a peculiar kind of Fusus, called Fusus contrarius, is found, having the whorl and the mouth in a con rary direction. Others are fresh-water shells; such as the Cyclostoma, 6-the Planorbis, 10-the Helyx, 12-the Cyrena unifor.nis, 1.

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the serpent. The crocodiles resemble those which now exist in Borneo. The tortoises are both marine and fresh-water, but the marine ones are fewer in number than the others, and they are smaller in size than those now existing. The serpents are of the tribe now represented by the Boa Constrictor and the Python, such as are now found only in tropical climates, and feeding on birds and quadrupeds. Some of them were of large dimensions and measuring in length from ten to twenty feet. All the tertiary reptiles approach the modern type, and all the present orders have their representatives in these deposits.

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It is remarkable that tertiary fishes of the same species are found in the most distant localities; such as the London clay of England, Monte Bolca in Italy, and in Lebanon in Asia. These fossil fishes resemble much those which are now found

in the Indian Seas and in the Southern Ocean.

The forms and shapes of some of these fossil fishes are :emarkably unique. One genus h as, behind its head, a fin that rises like a tall mast much higher than the length of the ole body. From this mast of a fin, to the tail of the fish, there extends a corresponding sail, by the aid of which it was able to navigate its course in the tertiary seas. Another fish is so curiously formed that the height of its body and its fins is three times as much as the length of the animal.

The various groups of tertiary fishes comprise many hundred species belonging to all the existing orders and families, of which nearly two hundred have been figured and described by Agassiz (pron. aggasee); of these forty or fifty belong to the family of the sharks, whose teeth are found in great abundance

in the tertiaries.

The ichthyological or "fishy" history of the tertiaries may be thus summed up. In the Eocene tertiaries one-third of the fish belong to extinct genera. In the newer tertiaries, such as the Crag, the races are of the genera common to tropical seas, and, throughout, the fossil fishes approach in their character to the living races, but all the species are extinct.

RE TILES.

The tertiary reptiles are of three classes-some inhabiting the land, others rivers, and others the brackish waters of estuaries; but they are all of a kind that prove the climate to have been of warm temperature. Among these, lizards and several kinds of crocodiles abound-so do also turtles and tortoises. But the most remarkable fact of this epoch is the existence of

BIRDS.

beds, several species have been found in the Paris basin, espeAlthough the remains of birds are very rare in the Eocene cially those resembling the pelican, the sea lark, the owl, the woodcock, and the buzzard. There have been some few and rare instances in which the fossil skeletons of birds have been well preserved.

The first who discovered the fossil remains of birds was

Cuvier. In some specimens he discovered even some fossil indications of feathers. In the lacustrine limestone of Auvergne in Central France, also the eggs of an aquatic species are found

fossil.

QUADRUPED3.

The land quadrupeds of the more ancient tertiaries are found fossil in much greater abundance in the gypsum beds of Paris than in the formations about London. There they include a great number of species chiefly of the group called Pachydermata, or the thick-skinned, represented now by the elephant, rhinoceros, etc.: but the most predominating are the carnivorous or flesh-eating quadrupeds, such as the wolf, fox, opossum, etc. In England also have been found a few fossil fragments of the teeth of creatures like the bat--and, what is most singular, of a monkey, as if, on Lord Mboddo's principles, approaches were made towards the production of man! All the fossil quadrupeds indicate a mach warmer climate in their localities than are found now. The name of this group is derived from Taxve, pachys, thick, and depua, derma, plural dermata, skins or hides.

Among the Pachyderms were creatures allied to the horse, of which the tapir of South America seems now to be the best living representative. Another of the tapir group was an animal called the Lophiodos, of which only very imperfect fragments have been found in a fossil state, but even those fragments point to the existence of more than twelve species. Its name is derived from Xogos, lophos, crest, and odwr, odon, tooth, i. e.

the crested-tooth. All these are supposed to have inhabited the dryer districts of the Eocene land. To the same group belong the better known fossil quadrupeds, the Palæotherium, and the Anoplotherium.

The PALEOTHERIUM was much like the living tapir in the form of the head, having a short proboscis or trunk; but its molar teeth resembled those of the rhinoceros. It was about three or four feet high. Unlike the tapir, it had only three toes to each foot, and it was also very slender. An animal between the tapir and the horse would probably be a good representative of the Palæotherium, though its species varied greatly. It is supposed to have inhabited districts near water. The name is derived from raλaios, palaios, old, and notov, therion, a wild beast.

The ANOPLOTHERIUM was less clumsy and more agile than the Palæotherium, and was a nearer approach to the ruminant group of animals. The Anoplotheria were abundant in the older tertiaries. The name is derived from a, (av before vowels,) privative, or without, ónλov, oplon, armour, and Onpiov, therion, wild beast: that is the unarmed animal. Two species have been ⚫ determined.

timid animal. In external character it was the small deer of the Eocene.

These quadrupeds are represented in figs. 1, 2, 3, and 4 In the Meiocene and Pleiocene tertiaries we meet with the deinotherium, the mastodon, the elephant, etc.

The DEINOTHERIUM, from devoç, deinos, terrible, and Onptov, therion, a wild beast, was remarkable in size, in relation both to the anoplotherians of the older beds on the one hand, and to the elephantine groups of more recent periods on the other. The fossil remains of the Deinotherium are nowhere more common than in the valley of the Rhine, between Basle and Mayence, and they are also frequent in the valleys of the Jura. This animal was of a huge barrel-shaped body, and was twenty feet long, and in character was something like the hippopotamus. Its body was but little raised above the ground, though its legs were ten feet high. It lived in water, but its head was kept entirely out of the water. Its head resembled that of the elephant, having a powerful proboscis, and also a pair of large and long tusks curving downwards like those of the walrus. What is most remarkable in these tusks is, that they are fixed in the lower jaw of the animal, to enable it to dig for succulent

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Fig. 2. Quadrupeds of the Tertiary Period.

1. Anoplotherium gracile. 2. Anoplotherium commune. 3. Palæotherium magnum. 4. Palæotherium minus. The first species was about as tall as a dwarf ass, but its food. It was the most gigantic of all the herbivorous or grassbody was much longer, with the appendage of an enormous eating quadrupeds. tail. It was particularly adapted to live in swampy districts and in marshes, where it fed on the roots and the leaves of aquatic plants. Its body was about eight feet long, with a skin nearly naked, and having its ears very short. Except the kangaroo, no living animal is known to have so long and so

powerful a tail.

The second species of Anoplotherium is called the Xiphodon, from tipos, riphos, a sword, and odwr, odón, a tooth, a creature very different in size, in proportions, and in habits from the first species. The graceful elegance of its skeleton reminds one of the gazelle. It might be about as high as a goat, but its head and trunk indicate a smaller animal. It lived on the banks of lakes and rivers, and on the borders of marshes, feeding on aromatic herbs and the young buds of trees. It was covered with a short hair, and was most likely a

size of the present elephants and with mammillated teeth. It
The MASTODON was another species of elephant, about the
abounded in the districts now called North America; where
perfect skeletons of it have been found in salt marshes, which
it visited for the sake of the salt, and where it frequently sunk
to be forty miles long by about twenty miles broad. In
in deep mud and perished. Some of these marshes are known
Warren County, New Jersey, six skeletons of the same mas-
todon were found, six feet below the surface, five of them lying
together.

from paoros, mastos, breast or pap, and odwv, tooth.
The name is given on account of its teeth being like paps

almost down to the human epoch, accompanied by some of the
This species continued to live through the Pleistocene periods,
animals which are now existing.

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