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as numerical abundance, and indicates genial and continuous geographical conditions-so genial as to give rise in

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RESTORED ASPECT OF OOLITIC VEGETATION.

Palm, Screw-pine, Araucaria, Cycas, Tree-fern, &c.

many areas (Europe, India, the Indian Islands, and North America) to repeated and valuable deposits of coal. Indeed, many coal-fields at one time attributed to the carboniferous

epoch have been proved to be of oolitic age,* and, as investigation is pushed still further, other areas, in both hemispheres, will be found to belong to the same geological system.

When we direct our attention to the fauna we find the lower marine animals abundantly represented, showing that in the oolitic seas there were those varied conditions of warmth, depth, sea-bottom, and shore-line essential to their dissemination and development. Sponges (spongia) are

by no means rare; foraminiferous organisms (lituola, rotalina, spirolina, &c.) are scattered throughout the formation; and corals (thamnastræa, montlivaltia, isastræa, &c.) of varied and elegant forms occur in vast profusion, and point to a time when the oolitic areas of Europe and Asia were instinct with coral-life, and dotted and barred with reefs like the existing seas of the southern hemisphere. Encrinites, though now on the wane, still star the sea-bed with their elegant forms (pentacrinus, apiocrinus, &c.); sea-urchins (cidaris, hemicidaris, diadema, echinus, &c.) throng the marine strata in increasing numbers; and freefloating star-fishes (astropecten, amphiura, and ophioderma), apparently replacing the encrinites, now approximate in generic aspects to those of the present ocean. Annelids, like the living serpulæ, cement their tortuous tubes to stones and dead-shells; barnacles (pollicipes) attach their many-valved mansions to rocks and floating timber; minute crustaceans (cypris, cypridea, and estheria) moult their bivalved crusts in myriads in the muddy creeks and estuaries; while the higher crustacea (glyphæa, eryon, and megacheirus) approxi

* The coals of Southern India, of Borneo, Labuan, Zebu in the Philippine Islands, &c., are now ascertained to be of oolitic age; to which epoch also it is suspected that most of those of China and Japan belong; as well as that of Virginia in America, and other localities. The oolitic coal-fields of Eastern Yorkshire and Brora in Sutherlandshire have been long known to British geologists.

mate in form and function to the crayfish and lobsters of existing waters. Insects, destructible as their remains may

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OOLITIC CRUSTACEA.

1, Eryon; 2, Megacheirus; 3, Archæoniscus ; 4, 5, Cyprides-natural size, and magnified.

seem, now assume an important place in the lists of the palæontologist-burrowers among the decaying timber of the pine-forests; leapers among the leaves and herbage of the cycas grove; hunters along the river-bank and across its sunny waters; and gaudy flutterers over the flowers of the lily and palm-tree. All the great orders of insect-life -beetles, cockroaches, dragon-flies, grasshoppers, and ants

-are abundantly represented, and their resemblances (if not affinities) are indicated at once by such generic appellations as buprestium, blattidium, libellelium, cicadellium, and formicium.

The waters are now thronged with molluscan life. The minute polyzoans or sea-mats weave their delicate network (diastopora, ceriopora, heteropora, &c.) over shells, encrinites, and every available ground-work-varying slightly in

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pattern, but still preserving that similarity of design which has ever characterised their beautiful structures. The deepsea, infusorial-feeding brachiopods, though specifically fewer than in the paleozoic periods, are still abundantly represented-terebratula, rhynchonella, spirifera, discina, and the like, being the dominant forms in the marine beds of

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1, Spirifer; 2, Avicula; 3, Terebratula; 4, Pholadomya; 5, Modiola; 6, Gryphæa;

7, Trigonia; 8, Plagiostoma; 9, Pleurotomaria.

the lias and oolite.

The true bivalves, now so greatly in the ascendant, present themselves in vast profusion, throng

ing every condition of sea-shore, and leaving their remains in every degree of beauty and perfection. Gryphæa, gervillia, avicula, lima, ostrea, and pecten; trigonia, modiola, pholadomya, cardium, astarte, and scores of other genera, occur in numerous specific forms in the marine beds of the lias and oolite; while fresh-water mussels (unionidae) are equally characteristic of the estuarine sediments of the

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1, Ammonites Jason; 2, A. communis; 3, A. Bucklandi; 4, Belemnites Puzosianus. 5, 6, Belemnites; 7. belemnoteuthis.

Wealden. The gasteropods, too, in many generic aspects, crowd the sea-shores-turbo, trochus, pleurotomaria, nerinæa,

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