The seaside naturalist. Out-door studies in marine zoology and botany, and maritime geology

Front matter

THE

SEASIDE NATURALIST.

OUT-DOOR STUDIES

Preface

Some years ago the Author, at the desire of the editor of an eminent periodical, contributed a short series of papers on one of the branches of the Natural History of the Sea-shore. The extremely favourable reception which those contributions had the honour to meet with from persons qualified to appreciate them, has encouraged him to present the following work to the Public.

Its nature and object are perhaps sufficiently indicated by its title ; the work has, therefore, not solely been written with the view of teaching geology, botany, or natural history, but no less of directing the reader’s attention to the many very striking illustrations of great and impressive truths which those departments of

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PREFACE.

science exhibit in the phenomena and productions of the sea-shore.

The studies to which the following chapters refer are calculated in no small degree to enhance the charms of a visit to the sea-shore, to yield recreation amidst graver toils, and to minister to intellectual and moral soundness, while the scenes in which they are pursued contribute to the increase of bodily health and vigour. It is the Author’s earnest hope that the volume he now submits to the reader’s perusal may conduce in some measure to such important results.

Pecten Quinquecostatus.

Introduction

Charms of the Sea-shore. — Classic and Oriental Myths relating to the Sea. — Various Studies suited to the Seaside. — What is requisite for such Studies — an Illustration from Botany. — Advantages of such Pursuits . . . • Page 15

Chapter II. Maritime Geology

Extent, Character, Variety of Aspect of our Sea-shores, and their Relation to Geological Structure. — General View of Geology. — Geological Tour from Cornwall and Devonshire along the Coasts of England and Scotland, exhibiting the General Features of our Sea-shores as regards their Structure 23

Chapter III. Changes In Our Sea-shore

Mutations of the Earth’s Surface indicated by Geology. — General View of their Causes. — Alterations which from Age to Age have occurred in various Parts of the British and Irish Coasts, and their Causes. — Analogous Changes in other Parts of the World 35

X

CONTENTS.

CHAPTER IY.

FOSSILS OF THE SEA-SHOEE.

General Views. — Fossils of the Palaeozoic, the Secondary and the Ter tiary Epochs, and various considerations regarding them Page 51

Chapter V. The Ocean

Aspect of the Ocean. — Sunrise and Sunset. — Extent.- — Relation to Rivers and Lakes. — Medium of Intercourse. — Depth. — Colour.— Saltness. — Circulation in the Ocean. — Coral Reefs, &c. . 73

CHAPTER YI.

WINDS AND TIDES.

Interest of the Subject. — Air and Water, Ocean and Atmosphere.

— Theory of the Tides. — Tidal Phenomena Rise of Tide in

various parts of the Coast. — The Bore. — Currents of the Sea. — The Winds 93

Chapter VII. Maeine Vegetation

Analogy between Marine and Terrestrial Vegetation. — Variety of the Algae. — Marine Botany, its Classification. — Specimens of the three Subdivisions in which our Sea-weeds are comprehended 107

Chapter VIII. Physiology Of Maeine Plants

Claims which they have on our Attention. — Fructification. — Peculiarity of their Structure. — Reproduction. — Their Remarkable Structure as related to the Element they exist in. — Artificial Uses of Sea-weeds. — Their Relation to Marine Animals. &c. 115

RAYED ANIMALS — STAR-FISHES.

Crinoideas of Primaeval Seas.— Different Families of the Star-fishes. — Their Structure, &c. — Ophiuridae. — Feather-star. — Sun-star. — Brittle-star, &c 171

Chapter XV. Rayed Animals — Sea-urchins

Antiquity of the Race. — Egg-urchin. — Complexity of Structure. —

Method of Enlargement Mechanism of Spines, of Mouth,

CONTENTS,

>ai

CHAPTER XYI.

ARTICULATA, OR JOINTED ANIMALS — MARINE WORMS, ETC.

Their Structure. — Tubicola? and Serpulse, &o. — Nereis. — Sea-mouse Page 185

VEETEBEATA — MAEITIME BIEDS.

Swimming and Wading Birds.— The Curlew.— The Sandpiper

Divers — Grebes.— The Gannet: its remarkable Structure 269

Chapter XXVII. Veetebeata — Seaside Mammalia

The Cetacea, or Whale Tribe. — The Dolphin. — The Sea Unicorn. — The common Whale: remarkable Adaptations of Structure, &c. — The Seal Family: Form and Habits. — Adaptations of Structure. — Conclusion. 275

XIV

ILLUSTRATIONS,

Chapter XXVIII. The Marine Vivary

The Principles of Life, Animal and Vegetable : Oxygen, Hydrogen, Nitrogen. — Filtration and Impurities. — Sand, Shingle, and Mimic Rocks. — Sea-water, Natural and Artificial. — Algae. — Zoophytes. — Molluscs. — Articulata : Tubiculae; Serpulae; Marine Worms; Crabs ; Prawns ; Shrimps. — Fish. — Tools. — Evaporation.

ILLUSTRATIONS.

PAGE

Cornish Pilchard Fishery Frontispiece

Confluence of Thames and Medway Title

The Nore Light v

Pecten Dujardinii vi

Gravesend Reach vii

Pecten quinquecostatus .... .... viii

Calamapora polymorphus ix

Tenby, from the North 15

Fossils of the Sea shore 51

Ammonites cordatus . . . 72

Cystoceira ericoides, magnified 92

Dictyota atomaria 108

Root of Laminaria 114

Chondrus crispus 124

Sea- Weeds and Maritime Flowers 139

Fucus vesiculosus and Desmarestia ligulata 143

Rayed Animals If A

Coral and Corallines 170

Fossil Sea Urchin 183

Fossil Astrea (Madrepores) 184

Jointed and Soft-Bodied Animals . 191

Fossil Encrinites moniliformis and Bourgueticrionis crinoidalis . 196

Lobster 208

Cray-fish 215

Bivalves 216

Sea-Urchins, Shells, and Coral 230

Mussel, Cockle, and Whelk 238

Remarkable Fishes . 239

Fishing-Frog, or Frog-Angler 246

Lamprey and Lampern 258

Sturgeon, Shad, and Bass 268

Maritime Birds 269

Sea Swallow 274

The Seal Family 275

The Whale 282

The Rectangular Aquarium ......... 283

Ulva, or Sea-lettuce . . 292

THE SEASIDE NATURALIST.

Chapter I

Charms of the Sea-shore. — Classic and Oriental Myths relating to the Sea. — Various Studies suited to the Seaside. — What is requisite for such Studies, — an Illustration from Botany. — Advantages of such Pursuits.

It is tlie month of June. The keen and withering blasts of Eurus, which blow with such direful pertinacity in April and May, are at last superseded by the soft west winds, fraught with health and oxygen from the luxuriant vegetation of the tropical lands where they have their birth. It must have been in this same month — the loveliest of the year — that “ holy George Herbert ” indited those lines so dear to quaint old Isaak Walton : —

“ Sweet day, so calm, so pure, so bright,

The bridal of the earth and sky! ”

In no other month does Nature exhibit so many and such varied evidences of that august bridal of which the poet gives so full and glowing a picture. Woods, meadows, rivers, hills, valleys, all vie with each other in presenting their various charms to the delighted wayfarer ; hut no scenes can advance stronger claims on his attention at this season than the sea-shore.

Let us wander along the beach. On one hand is the sea : its surface is rippled by the fresh breeze ; the tide is gently encroaching on the sands ; the wavelets falling in quick succession, utter their murmurs in a monotone not unmusical to a poet’s ear. On the other hand, there are rocks whose bases have for thousands of years resisted the storms of winter, and whose summits are crowned with trees, and flowers, and waving ferns, and from a rift in which falls a clear sparkling runnel, that, after wandering through woods and fields, at length leaps over the rock and loses itself in the sea. Then, high overhead, the sky is of that same deep blue which we see reflected in the waters beneath ; and here and there far aloft are clouds of that kind which meteorologists tell us never betoken rain, and which, as the rays of the sun light them up, seem lovely enough to realize the poet’s dream, that

“ Some angels in their upward flight Had left their mantles floating in mid air ; ”

and the no less poetical fancy of the philosopher, that such radiant forms might be the vehicles on which denizens of some of the planetary worlds might pass from place to place through the fields of ether. Then far at sea, on the verge of the horizon, there are a few ships, with only a speck of snowy canvas visible, for the convex waters interpose between their hulls and the spectator’s eye ; while only a few hundred yards off, a flock of gulls

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are floating on the waves, screaming to each other as if discussing the probabilities of a contemplated attack on the next shoal of small fry that make their appearance near the surface. None but very ordinary observers can resist the attractions which heaven, and earth, and sea thus unite in presenting to the visitor of the sea-shore ; and so, without any disparagement to the special charms of purely rural scenes, we reiterate our conviction that in this lovely month of June no charms of natural scenery exceed those of our sea- shores.

Let us seat ourselves beneath the grateful shadow of this rock, and no longer resist the spirit of contemplation which whispers to us in these whispering waves.

What an inexhaustible fund of strange and marvellous knowledge does not that sea contain ! What mysteries amid its depths ! What wonders in the structure and habits of its denizens ! In its tides and currents how much that is interesting and marvellous ! In its storms and calms how much that is grand and sublime ! In all that pertains to the great deep how striking and how solemn the lessons uttered as to Creative wisdom, and power, and foresight, bidding us

“ own

The Hand Almighty who its channelled bed Immeasurable sunk, and poured abroad,

Fenced with eternal mounds, the fluid sphere ! ”

Looking upon the sea on a day so lovely as this, one ceases to marvel at those wild and wayward fancies of Greek and Oriental mythology which loved to people the realms of ocean with nymphs and deities endowed with natures suited to the element in which they were presumed to exist. How favourable to the birth and development of such charming myths must have been the

B shores of Baiae, or the isles that stud the blue Egean ! With cloudless azure above, and serene waters below, and all nature breathing grace and beauty, how natural the idea that those bright waters were the abode of the Nereides, marine damsels, ever blooming in youth and loveliness, and who by the favoured few might sometimes be seen disporting on the backs of dolphins, or frequenting, on the sea-shore, caves and grottoes, adorned with flowers and sea- shells ! How natural too, and how credible to a fervid imagination, the story of Ceyx and Haley one, told in strains of such tender melancholy by Ovid, in which the faithful pair are reunited in the form of birds dear to the sea-nymphs, and which make their nests on the sea foam when winds and waters are at rest ! The desire one feels to be able to take up one’s abode beneath these mysterious waves would itself render perfectly credible in Classic times the history of the Boeotian fisherman who, perceiving that the fish he had caught on being thrown upon the grass were endowed with new life and enabled to regain their native element, imitated their example, and tasting the miraculous herbage, became forthwith a denizen of the deep.

How charming would it be if, as we are here seated contemplating those waves, we should suddenly find the Arabian myth of Abdallah of the Sea realized ! How gladly should we accept a polite invitation to visit the caves of the ocean, protected by the enchanted unguent from all inconvenience which a descent beneath the waters would otherwise cause to our organs of respiration ! How pleasant is this warm weather to visit in safety those crystal depths, where the finny tribes lead “ their cold sweet silver life, wrapped in round waves ! ” Beneath the liquid crystal would await us scenes more wonderful than the fairy dreams of childhood.

It is hopeless, however, to await a visit from Abdallah ; for that remarkable personage dwells, it is more than probable, only beneath those bright waves which bathe the shores of Yemen, and so cannot be expected to emerge from our hyperborean waters. We have nothing for it, therefore, but to content ourselves with what our sea- shores themselves present us.

Happily no preternatural aid or direction is required to enable us to perceive the objects with which the sea-shores furnish us. They are many and various. They all belong more or less to Natural History in its more comprehensive acceptation ; and Natural History is itself a charming study.

Then we have to consider the aspect, the character, and the structure of our sea- shores ; the ocean itself, with its special laws and history ; marine vegetation and littoral plants ; and a great variety of living beings which either make their abode continually on our shores, or only visit them from time to time. Such objects, so many and so various, invest our sea- shores with the greatest novelty ; for the most diligent and industrious observer cannot with all his labour exhaust the store even of the microscopic objects alone which the sea-beach affords. Be it observed, however, that to reap the full advantage which such studies are capable of conferring, some particular knowledge is requisite, as well as diligence and attention.

A very simple illustration will be sufficient to explain this. Let us suppose, for example, the case of a person entirely ignorant of the botany of field flowers. He never

The Seaside Naturalist .

heard of the artificial system of Linnaeus, or the natural system of Cuvier. He has no more acquaintance with one flower than another, as regards its structure, its functions, its habits, or its qualities. To such an individual a ramble through the fields or woods in spring presents little more than the fact, that the hedge-rows, the meadows, and the trees are again assuming their verdant garniture, and that, after the long sleep of winter, nature is once more exhibiting a cheerful aspect. The want of special and particular acquaintance with the science of botany deprives him of numberless pleasing impressions, which would otherwise be made upon his mind by the reappearance of those objects in the vegetable kingdom to which he had given attention in some preceding season.

“ A primrose by the river’s brim A yellow primrose is to bim,

And it is nothing more.”

The Book of Nature has opened its pages before his eyes; those pages are distinctly printed and gloriously illustrated ; but to him they are in a great measure written in an unknown language, and the characters fail to awaken in him more than a few vague and indefinite ideas.

How different is the case of the person who is even but imperfectly acquainted with botany ! To him a solitary ramble among the green lanes and shadowy woods offers an inexhaustible fund of cheerful, healthful, elevating contemplation. He can read the book that is open before him, and comprehend much of its language. The simplest flower that springs up beneath the hawthorn hedge suggests to him a train of ideas. Every leaf that issues from nature’s press is in his view like the Prophet’s roll, printed

The Seaside Naturalist .

within and without in characters full of the sublimest significance ; every blade of grass is vocal to him, and, awakening the echoes of memory, renews past impressions and past enjoyments. To him there are sermons not only in trees, but in the humblest flower beneath his feet ; in the moss that crowns the mouldering wall, the little fern that grows on its sides, or the various coloured lichens that give their peculiar tints to the stones that form it.

These remarks are not less applicable to a ramble by the sea-shore than to a walk among the rustic places of the inland country. In both instances some special and particular knowledge is essential to the pleasure and enjoyment of the observer ; and with such particular acquirement the wanderer by the seaside may convert even the murmur of the ocean into an articulate voice, and understand much of what the “ wild waves are saying.”

No study is better calculated to strengthen our corporeal and mental faculties, or to recruit them when weaned or overtaxed, than that of the Natural History of the Seashore. Even the fresh air, the exercise, the freedom from restraint connected with these pursuits, are for a large number of human ills medicines, in the universality of which all physicians are agreed from the days of Hippocrates and Galen to the present hour. And what a solace to mind and body to leave behind the thousand and one “ winged cares” which the poet tells us flit about the ceilings of our abodes ! What a delight, if they still pursue us as we drive away to the beach, to bid them begone, or, if they succeed in entering the boat with us, to push them over into the bright waves ! Nay, the very effort thus to obtain freedom, albeit it may not be entirely successful, is itself conducive in no small degree to mental and corporeal vigour.

Then in the objects themselves which we study how much is there that is wholesome to the moral and intellectual powers as fresh air and exercise to the bodily functions ! The various departments of natural history, of which the sea- side furnishes illustrations, exhibit innumerable organized structures, singularly beautiful in themselves, and marvellously adapted to places, conditions, and circumstances. It ministers in no small degree to the health and vigour of the mind to examine such structures, and note such adaptations, and suffer them to enforce the lessons they read us as to Creative power, foresight, and beneficence.

It is not necessary for us to inquire as to the manner in which Creative power and wisdom have been exercised. We are not called upon to determine what the method may have been or may still be ; whether the great Originator has produced the organisms we admire, directly or indirectly by the action of general laws. Whatever view we may take, the result is the same. We discover substances and elements highly complicated in their relations, resulting in organisms so adapted to the conditions they are placed in, that it is impossible not to admit that the adaptation is designed by the same Agent in which the structure itself originated. Such, indications are extremely various and numerous, and to these we invite our reader, to discern with us some of the striking truths of what we venture to denominate Seaside Divinity.

The Seaside Naturalist.

CHAPTEE II.

MARITIME GEOLOGY.

Extent, Character, Yariety of Aspect of our Sea-shores, and their Delation to Geological Structure. — General View of Geology. — Geological Tour from Cornwall and Devonshire along the Coasts of England and Scotland, exhibiting the General Features of our Sea-shores as regards their Structure.

The shores of the British Islands, including those of the many smaller isles which form the group, comprehend, when measured along the extremely irregular line of our numerous hays and estuaries, a circuit of several thousands of miles, and exhibit throughout their vast extent the utmost variety of scenery and aspect.

In some instances the shores are tame and uninteresting ; but as a general rule they possess great beauty and grandeur. In some parts of the coast the land slopes gently toward the sea, and is either clothed with trees, or consists of rich meadows and cultivated fields, and is terminated by a beach of smooth sand or of pebbles mingled with shells. In others the coast is bounded by precipitous cliffs of great altitude, exposed to the perpetual action of the billows, and presenting features of the wildest and most romantic character. In the one case the wanderer easily gains access to the water’s edge, and may enjoy the charms of the seaside “ in summer eve,

"When the broad shore retiring waters leave,

And all is calm at sea and still on land.”

On the other, all access to the water is impracticable, for it is often of profound depth, and it never leaves the base of the cliffs. But ample amends are made in the

The Seaside Naturalist.

sublimity of the scenery, and the extent of the view which from such situations can be obtained.

The variety of features thus presented to us in the scenery of our sea-shores may be traced in a great measure to peculiarities in their geological structure. But there are other respects besides form and outline in which the geology of our shores modify their aspect. The vegetation, both in its amount and its character, depends in a very considerable degree on the nature and properties of the soil ; and the soil in its turn is dependent for its quality on the rocks and strata on which it rests ; and hence the geology of any particular district is concerned in modifying the character of the vegetation. Thus the tameness or the sublimity of the scenery, and the scantiness or the luxuriance of the terrestrial plants by which the scenery is adorned, may originate in the same cause.

These remarks may to some extent be illustrated even by a very general view of the geology of Britain. The Tertiary formations are for the most part spread along the eastern and south-eastern maritime districts ; the formations of the Plutonic rocks and the strata of greatest antiquity occur for the most part on the western coasts. This imparts a corresponding variety to the eastern and western shores. The latter are generally bold and precipitous, the former comparatively tame and low. The natural productions of the soil, too, exhibit a corresponding difference. In the latter they are scanty compared with the luxuriance they exhibit in the former.

To those acquainted in any considerable degree with the variety of aspect presented by our sea-shores, a view of the geological phenomena on which that variety so much depends can hardly fail to prove interesting. We shall, therefore, exhibit to the reader such a sketch as is

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compatible with the nature of this work, in the form of a Geological Tour along the Coast. It will, however, facilitate our design to take a rapid survey of the chief divisions of geological science.

The solid materials of the globe are by geologists understood to consist of the igneous rocks or those left in their present condition by the action of heat and the aqueous formations, or the strata originating in the action of water. These two great classes comprehend, it need hardly be added, a great number and variety of rocks and strata, more or less distinguished from each other by peculiarities of structure and composition. The “ igneous rocks” are of great value in all geological investigations. They are the monuments of vast organic convulsions, caused by stupendous force to which the surface of our planet has been subjected, and they have acted a most important part in causing the diversity of elevation exhibited on the surface of the earth, giving origin to hills and mountains and valleys, with all their variety of scenery ; and so causing the conditions necessary to the existence of springs, rivers, and lakes, from which results so much variety and beauty of scenery. But a still higher interest belongs to the study of the stratified formations; for the various organic remains they contain are a record of the past history of the earth, by indicating the character of the plants and animals by which it has been successively inhabited, and by pointing out, in some degree, the nature of the soil, the climate, and in general the physical geography of the earth, in periods incalculably remote from the present time.

One of the most remarkable truths disclosed by geology is, not merely that multitudes of the remains of plants and animals peculiar to former conditions of the

2 6

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earth are preserved in the stratified rocks, but that in many instances these rocks, although of vast depth and extent, are formed almost exclusively of the remains of creatures once endowed with the senses and functions of vitality. This truth, wonderful as it is, is not inconsistent with the wide and all hut universal diffusion of life at the present moment ; and it proves that in the remotest ages of the earth’s history the mysterious principle of vitality was employed by its Divine Originator to minister with a most energetic agency to a great variety and multitude of chemical and organic combinations carried on in the great laboratory of nature.

Eaces of beings belonging to an epoch of incalculable duration lived and perished, leaving their exuviae in the solid rock as memorials of their existence. These were succeeded by others of different forms and habits, who also becoming extinct, bequeathed to subsequent times a history of themselves and their age, written, like that of their predecessors, in the durable materials of the globe ; they in their turn were succeeded by others of dissimilar forms ; these again by others ; so that the mutations which geological inquiries disclose may truly be considered as the history of life and its metamorphoses.

Commencing our tour at the Land’s End, and proceeding eastwards along the shores of Cornwall and Devonshire, the remarkable circumstance attracts our attention, that the whole of the coast, with certain exceptions, is formed of the old red sandstone, to which the term Devonian strata is applied, but which sparingly occurs in any other district of England, while it constitutes a large portion of the central and northern divisions of Scotland and a considerable portion of Wales. Associated with this prevailing formation we find, moreover,

The Seaside Naturalist .

granite rocks, which form the Land’s End ; serpentine, which constitutes the Lizard ; mica and chlorite schists at the promontory of Start Point, and several instances of trap and porphyry occurring at intervals. Proceeding onwards, we discover that the formation of the Palaeozoic era of Devonshire is succeeded on the shores of Dorsetshire by the formation of the Secondary era, the oolite and lias, which latter forms the cliffs near Lyme Kegis. Along the Hampshire coast formations belonging to the same epoch occur, consisting of the chalk, the wealden, and the oolite, associated in certain places with freshwater and marine tertiary deposits. Advancing towards Brighton, we find the Cretaceous formation, which constitutes the foundation strata of the district, rarely exhibits itself, the shores being for the most part low, and composed of tertiary and alluvial deposits. To the east of Brighton, however, a bold line of chalk cliffs bounds the shore towards the river Ouse, extending to the promontory of Beachy Head, succeeded to the eastwards by the lower series of the Chalk formation, firestone, gait, and greensand, which occur on the southern shores of the Isle of Wight and along some parts of the coast over which we have already passed. Eastwards from Beachy Head, we enter upon the Wealden formation, the range of cliffs which skirt the shore being formed of the Wealden sandstone alternating with clays and shales. From Dover to the N. Foreland, the coast line is formed of chalk cliffs ; and at Folkestone and Hythe in particular the lower series of the Cretaceous formation is manifested, the greensand strata being at the base and on a level with as well as reaching beneath the sea, the gait lying over the greensand, the firestone resting on the gait, and over all the lower and upper chalk formations.

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Continuing our journey along the coast, we find the Tertiary deposits extend from the north-eastern shores of Kent to the chalk hills of Wiltshire, Berkshire, Oxfordshire, Buckinghamshire, and Hertfordshire toward the west, and northwards to the extreme limits of Norfolk. To this formation belongs the London clay, which is of great depth, and spreads over an extensive area around the metropolis of England. This clay lies in a basin which formed in some remote era the bottom of a gulf of the ocean, and like the various strata already noticed, it constitutes an object of the deepest interest to the geologist, from the abundance of organic remains which it discloses.

On the northern shores of the county of Norfolk, the Cretaceous formation is again manifested, and from this point along the coast of Lincolnshire and beyond the Humber into Holderness, the coast line is chiefly made up of low cliffs of gravel, marine detritus, and tertiary deposits. The promontory of Flamborough Head, which we now reach, is formed of chalk, to the north of which the coast boundary is formed of various members of the Oolite and Lias formations. From the river Tees to Tynemouth the trias deposits and the magnesian limestone of the Permian system occur, and beyond this point to Berwick the coast is formed by the Carboniferous system, interrupted at intervals, as at Dunstansborough and Bamborough Castle, by masses of trap rocks.

From the rapid view we have thus taken of the geological features of the southern and eastern coasts of England, it will be observed that it is only towards the extremities of this long line of coast that any instances of the plutonic rocks occur, as in Cornwall, Devonshire, and Northumberland ; and that, with the few exceptions thus presented by some of the more remarkable head-

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lands on the southern and northern coasts, the entire shores are composed of strata belonging either to the Palaeozoic epoch or to the Secondary or Tertiary eras.

Before supposing ourselves to cross the embouchure of the Tweed and continue our expedition, one or two general remarks regarding the geology of Scotland will not he out of place. Geologists by very distinct natural lines of demarcation, have divided this portion of Britain into three great geological provinces. The Southern province lies between “ the borders ” and a line running from near St Abb’s Head, in Berwickshire, in a direction S.S.W., to near Girvan, in Ayrshire ; the Middle province is comprehended between this latter boundary and a line running also S.S.W., from near Stonehaven, on the east coast, to the middle of the Island of Bute and Cantire on the west ; and the Northern province includes the whole region beyond this line. Each of these districts is distinguished by certain general characteristics. The first -mentioned region is that of the formation termed by Werner the Transition rocks, but to which the title of Silurian system is now applied. It consists in a great measure of grauwacke, limestone, and slate rocks, and in some localities the plutonic or unstratified rocks make their appearance, such as granite, porphyry, and basalt. The Central region, of which the boundaries have been already stated, consists, like the preceding, of formations belonging to the Palaeozoic epoch, and. chiefly of the Devonian and the Carboniferous formations ; the former consisting of the old red sandstone, conglomerates, and other strata of an analogous character ; and the latter of layers of ironstone, limestone, and beds of coal. The third, or most Northerly region, comprehending within its limits a space nearly equal to both the divisions