the fish, and cause them to quit the places where that practice is followed; it is therefore strictly forbidden." (Yarrell.) The young are found on our coast during the summer months in great abundance, and are often taken in small-meshed nets used for catching other fishes.

The food of the Herring consists principally of small Crustacea, but they have been known to devour the fry of their own species.

Č. Leachii, Leach's Herring. This second species of herring was discovered by Mr. Yarrell, and described in the 'Proceedings of the Zoological Society' for 1831, p. 34. An account by the same gentleman is also given in the 'Zoological Journal,' vol. v., where a figure of the species will be found, as well as in his 'History of British Fishes.' The following is Mr. Yarrell's description:

"The length of the head, compared to that of the body alone, without the head or caudal rays, is as one to three; the depth of the body greater than the length of the head, and, compared to the length of the head and body together, is as one to three and a half; it is therefore much deeper in proportion to its length than our common herring, and has both the dorsal and abdominal lines much more convex: the under jaw longer than the upper, and provided with three or four prominent teeth just within the angle formed by the symphysis; the superior maxillary bones have their edges slightly crenated; the eye is large, in breadth full one-fourth of the length of the whole head; irides pale yellow; the dorsal fin is placed behind the centre of gravity, but not so much so as in the common herring; the scales are smaller; the sides without any distinct lateral line; the edge of the belly carinated, but not serrated; the fins small. The fin-rays in number are-dorsal, 18; pectoral, 17; ventral, 9; anal, 16; and caudal, 20. Vertebræ, 54.

"The back and upper part of the sides are deep blue, with green reflections, passing into silvery-white beneath. The flesh of this species differs from that of the common herring in flavour, and is much more mild."

Mr. Yarrell first discovered this species when examining the various kinds of fishes caught by the fishermen engaged in taking sprats. C. Sprattus, the Sprat, called in France Le Melet, Esprot, or Harenguet. This fish has by many authors been confounded with the young of the herring. It is however distinct, and its characters were first pointed out by Pennant; they are as follows:-proportions nearly the same as those of the herring, but the depth of the body is greater in proportion than in the young of that species; the gillcovers are not veined; the teeth of the lower jaw are so minute as to be scarcely visible to the touch. The dorsal fin is placed farther back, and the keel to the abdomen is more acutely serrated than in the herring.

Sprat-fishing commences in the early part of November; hence in season they immediately follow herrings, and the markets continue to be supplied with them during the winter months. Like the herrings these fishes inhabit the deep water during the summer: they are so plentiful as to be frequently used for manuring the land, and are often sold as low as 6d. per bushel.

C. alba (Yarrell), the White-Bait; French, Blanquette; German, Brietling. This fish has been supposed to be the young of the Shad. Mr. Yarrell however, upon a careful investigation of the subject, ascertained it to be a distinct species. Its distinguishing characters are:-Length of the head compared with that of the body, and not including the tail, as two to five; depth, as compared to the whole length of the fish, as one to five; keel of the abdomen distinctly serrated, but not so sharp as in the Shad. The dorsal fin commences half way between the tip of the muzzle and the end of the tail; the upper jaw is slightly crenated, the lower jaw is the longer, and is smooth. Its colour is silvery-white, growing greenish on the back; the body is more compressed than in the herring, and the keel to the abdomen is more sharply serrated than in either that fish or the sprat.

The White-Bait is caught in great abundance in the Thames as high up as Woolwich and Blackwall. The fishing commences about the beginning of April, and is continued to September. "When fishing as high as Woolwich," says Mr. Yarrell, "the tide must have flowed from three to four hours, and the water become sensibly brackish to the taste, before the White-Bait will be found to make their appearance. They return down the river with the first ebbtide; and various attempts to preserve them in well-boats in pure fresh water have uniformly failed." The food of the White-Bait consists of small Crustacea. Dr. Parnell states that he has taken White-Bait in the Frith of Forth in considerable numbers during the summer months. It is also taken in the Ex and other rivers of England. When fried with flour it is a favourite dish with all classes of the community; and amongst the English few entertainments are more popular than White-Bait dinners. It is the young of the season that are taken in such large numbers in the Thames. The adult WhiteBait are taken on the Kentish and Essex coasts throughout the winter. C. Pilchardus, the Pilchard; Le Celan of the French. In size this fish resembles the herring; it is also nearly of the same form, but rather thicker, and of greater proportionate depth; the scales are larger, the head is shorter, the suboperculum is square, and the dorsal fin is more forward in position; the gill-covers are distinctly veined.

This fish is caught off the coast of Cornwall in great abundance;

the fishing commences in July. The food of the Pilchard consists of small shrimps and other crustaceous animals.

C. alosa, Linnæus (Alosa finta, Cuvier), the Shad, is another fish belonging to this group. Cuvier separated this, together with several other species, from the true Clupea, from the circumstance of their having the upper jaw deeply notched in the middle.

Two species of Shad are found off the British coast; the first, the Twaite Shad of Yarrell, known generally by the name of Shad (Alosa finta), is about 14 inches in length; its colour is brownish-green on the back, or inclining to blue in certain lights; the rest of the body is silvery; five or six dusky spots are observed on each side, and are disposed longitudinally, the first close to the head, and the others at short intervals; the length of the head, as compared with the body, is as one to five; the body rather exceeds this measurement in depth; the jaws are furnished with distinct teeth, and the tail is deeply forked.

This fish is found in the Severn and Thames in tolerable abundance. The principal fishing season for the Shad in the Thames is about the second week of July. They begin to ascend the river about May for the purpose of depositing their spawn, and this being done they return to the sea about the end of July.

In former times the Shad was caught as high up the river as Putney; it now rarely passes London Bridge, and is caught in the greatest abundance a little below Greenwich. Its flesh is dry, and therefore not much esteemed for the table.

The second species of Shad, the Allice, or Allice Shad of Yarrell (Alosa communis), is considerably larger than the one just described, being from two to three feet in length: it may moreover be distinguished by its having only one spot on the side of the body, near the head, and that is sometimes scarcely visible: the jaws have no distinct teeth, and the scales of the body are rather smaller in proportion, though they are large in both species.

The Allice Shad is plentiful in the Severn, but of rather rare occurrence in the Thames.

C. encrasicolus (Linnaeus), the Anchovy (Engraulis encrasicolus, Fleming; Engraulis vulgaris, Cuvier). This fish, which is a favourite condiment, is a native of the British seas. It has been taken in the river Dart; and Mr. Couch, in his 'Cornish Fauna,' says, "This fish abounds towards the end of summer, and if attention were paid to the fishery enough might be caught to supply the consumption of the British Islands. It is abundant on the coast of Wales:" and Mr. Yarrell says, "The Anchovy is reported to be at this time an inhabitant of the large piece of water below Blackwall called Dagenham Breach; and in May 1838 I received one that was caught in the Thames, where however this species is so little known that the specimen referred to was sent to me with a request to know what fish it was." [ANCHOVY.]

CLU'SIA, a genus of Plants belonging to the natural order Clusiaceae or Guttiferæ, named after Charles de l'Ecluse, or Clusius, one of the most celebrated botanists of the 16th century. [CLUSIUS, CAROLUS, in BIOG. DIV.] It has a calyx of four imbricate coloured permanent sepals, the outer ones smallest, usually doubly bracteate at the base; the corolla of 4-6 deciduous petals; the stamens numerous and free in the male flowers; few, sterile, and connected in the female flowers; the style absent; the stigmas 5-12, radiately peltate, sessile, permanent; the flowers usually polygamous; the ovary surrounded by a short staminiferous nectary; the capsule fleshy, 5-12-celled, opening by valves from the top to the base, with a dissepiment in the middle of each valve; the placenta thick, triangular, central; the seeds egg-shaped, surrounded by pulp, suspended from the inner angle of the cells; the embryo straight, inverted; the cotyledons separable. This definition includes the genus Quapoya of Aublet. The species are trees and shrubs, usually parasitical, and yielding a viscid resinous juice, of a balsamic flavour; hence they are called in England Balsam-Trees.

C. rosea, Rose-Flowered Balsam-Tree, has polygamous flowers, a rose-coloured 5-6-sepaled calyx; the tops of the dense nectaries awlshaped; 8-12 stigmas; the leaves obovate, obtuse, veinless, sometimes emarginate, on short striated petioles. It is a native of the Carolinas and St. Domingo, and other parts of tropical America. The fruit is green, and of the size of an apple, with eight lines running like the meridians of a globe: when it ripens it opens at these lines, disclosing its scarlet seeds lying in the midst of a pulpy mucilaginous matter, similar to the pomegranate. The whole tree is very handsome, but few fruits offer so beautiful a piece of mechanism. "It grows on rocks, and frequently on the trunks and limbs of trees, occasioned by birds scattering or voiding the seeds, which being glutinous, like those of the mistletoe, take root in the same manner; but the roots not finding sufficient nutriment spread on the surface of the tree till they find a decayed hole or other lodgment wherein is some small portion of soil: the fertility of this being exhausted a root is discharged out of the hole till it reaches the ground, where it fixes itself, and the stem becomes a large tree." (Loudon.) The resin collected from this plant is used as an external application in veterinary medicine, and also is employed for covering boats instead of tallow and pitch.

C. alba has hermaphrodite flowers, a many-leaved calyx; corolla with 5-8 petals; tops of nectaries retuse, or with 5-10 short stamens ;

approaching to a cylinder. The body is elongate, and nearly cylindrical; the antennæ are shorter than the body, and filiform; the basal joint is rather thick; and the terminal joints are sometimes incrassated; the legs are moderately long.

These insects are generally of moderate size, and have the elytra adorned with arcuated fascia; their ground colour is usually black or brown, and the markings yellow.

About 90 species of this genus have been discovered, and they appear to inhabit every quarter of the globe; 5 are recorded as British, of which the more common are C. mysticus, C. Arietis, and C. arcuatus. C. mysticus is about half an inch in length; colour black; the base of the elytra red-brown; three bent white fascia are situated near the middle of the elytra; and there is a white patch at the apex. This species is common in the neighbourhood of London. We have frequently found its larva in the rotten wood of old blackthorns.

C. Arietis is about the same size as the last; its colour is black; legs and base of the antennæ reddish; the former with the thighs of the two anterior pairs blackish; thorax with a yellow band on the anterior part, and another on the posterior; scutellum yellow; elytra with four yellow bands.

This insect is frequently met with in gardens and woods in the neighbourhood of London and elsewhere. When handled it makes a peculiar noise, which seems to be produced by the friction of the thorax against the smooth part of the abdomen which is inserted in that part. Many of the Cerambycida have this power.

C. arcuatus is less common than either of the preceding species; it somewhat resembles the C. Arietis, but is considerably larger and broader in proportion. The antennæ are entirely of a reddish-yellow colour; the legs are coloured as in the last-mentioned species; the thorax has a yellow band on the fore part, and an interrupted band in the middle; the elytra have three yellow bands, and towards the base three spots of the same colour; the scutellum is also yellow. CNEMI'DIUM, a genus of Spongiada, proposed by Goldfuss for some fossils usually ranked as Mantellia and Siphonia. COAGULATION. [BLOOD.]

COAITA, or QUATĂ. [ATELES.] COATIMONDI. [VIVERRIDE.]

COAL, an opaque combustible mineral substance of a black or brown colour, and in all cases giving indications of having been derived from a vegetable source. Such is a definition that would probably include all those substances which are used in domestic economy and the arts for the purposes of combustion, and popularly called Coal. At the same time it should be stated that the term has at present no special scientific application that is universally admitted, and each investigator thinks himself at liberty to apply the term in accordance with his own views. As the knowledge of chemical principles and methods of investigation have advanced, substances which at one time were regarded as identical have been shown to have a very different chemical composition as well as microscopic structure. This has led in some instances to the discussion of the question, What is Coal?

For instance, in our courts of law, one of the most recent casesthat of Gillespie v. Russell-was tried in Edinburgh during the present year (1853). In this case, by an agreement for a lease entered into between the plaintiffs and defendants, the former agreed to grant to the latter a lease of "the whole coal, ironstone, iron-ore, limestone, and fire-clay, but not to comprehend copper or any other mineral whatsoever." It was alleged by the plaintiffs that, although the defendants had in the course of their operations come upon iron-ore and ironstone, coal, and fire-clay of workable value, they had neglected these, and had chiefly worked a certain mineral substance which the plaintiffs contended was not let to the defendants, not being one of the mineral substances specified in the agreement. This mineral was of much greater value, it was stated, than any which the defendants were permitted to work. Although used as a combustible material, it was alleged that this substance was not coal, and that its chemical, microscopical, and mineralogical characters were not those of coal. On the other hand, it was asserted by the defendants that the mineral in question was coal; that they had been led to seek a lease of the Torbane-Hill estate from the fact that on the adjoining lands of Boghead this mineral existed, and was worked and sold as coal, being known in the markets by the name of the 'Boghead Gas Coal.' This mineral, they contended, was true coal belonging to the variety known as Cannel or Parrot Coal. This trial was interesting on account of the large number of chemists, mineralogists, geologists, and microscopists examined, who appeared in about equal numbers on either side; one set of them contending that the mineral was coal, whilst the others contended it was not. A large amount of interesting facts on the nature of coal and the substances with which it is found associated was laid before the jury, who came to the conclusion that, whatever might be the result of scientific investigation in more rigorously defining the nature of coal and limiting the use of that term, both plaintiffs and defendants called this mineral coal when the lease was drawn up, and therefore gave a verdict in favour of the defendants.

The same question which has thus been debated in Scotland has also come before the law courts of Germany and of the United States

of America with the same differences of opinion; and we refer to these cases to show the difficulty of defining accurately this well-known substance. It may be regarded in the present state of our knowledge as one of those instances in which the typical form is lost by irregular combination with other and different substances.

That Coal is and must be of vegetable origin seems to be agreed upon by all inquirers, but the question of how to determine that origin in particular cases is the difficulty. Again, it is well known that coal after it is deposited undergoes certain chemical changes by which substances with a very definite chemical character are produced, such as bitumen, paraffine, &c. These, mixed with the coal itself and the earthy matters around, may form compound substances about whose nature there may be considerable difference of opinion. This is not improbably the case with the Torbane-Hill mineral, and will account for the peculiarity of both its chemical and microscopical characters.

Coal presents itself ordinarily in a massive form, and is brittle or sectile. It has a hardness of 2.5, and a specific gravity of 1.2 to 1.75. It is opaque, and has a black or brown colour. Its chemical composition is distinguished by the presence of carbon; in addition, it also yields, on ultimate analysis, hydrogen, oxygen, and nitrogen. On burning it leaves an ash which consists of varying quantities of silica, alumina, and oxide of iron. The carbon and hydrogen are often found chemically united to form bituminous compounds which are mixed with the coal. It is the presence of these compounds which causes coals to burn with a bright flame; at the same time they give off a bituminous odour. Those destitute of bituminous compounds burn with a pale blue flame, due to carbonic oxide, which is formed in these cases through the decomposition of the water present. The following table, founded on Mr. Mushet's Analysis of Coal, is taken from Professor Ansted's Elementary Course of Geology, Mineralogy, and Physical Geography :

Welsh beds.

The Bituminous varieties of Coal present greater differences of structure and appearance, and have a larger number of names. By the above analyses it will be seen that the quantity of Bitumen, or substances resembling it [BITUMEN], differ very much in different specimens of coal. It is generally softer and less lustrous than Anthracite, although occasionally specimens exhibit a very brilliant fracture. Its specific gravity is less than that of Anthracite, seldom exceeding 1.5, whilst the specific gravity of Anthracite ranges from 1.3 to 1.75. The kinds of this coal are known by various names. The following are analyses of the different kinds of Coal as they

occur in the Newcastle beds :

Pitching or Caking Coal is known by its velvet or grayish-black colour. When first thrown on a fire it breaks into small pieces, but on the continued application of heat the pieces again unite into a solid mass or cake. It burns readily with a yellow flame, but on account of its caking quality it is likely to clog the fire unless it is frequently stirred. The Newcastle beds mostly yield this form of coal. Cherry Coal resembles in external appearance the pitch coal, and when exposed to heat it cracks and flies, but does not cake. It is

very brittle, and on this account much loss is occasioned in mining it. It burns with a clear yellow flame. This kind of coal occurs in the Glasgow beds.

Splint Coal is a variety found in connection with the last, and is remarkable for its hardness; for which reason it is sometimes called Hard Coal. It is also found at Glasgow.

Cannel Coal has little lustre, is very compact and smooth in its texture, and breaks with a large conchoidal fracture. It burns very readily, giving out a clear yellow flame without melting. In consequence it has been employed for the making of candles-hence its name. It is often employed for making inkstands, snuff-boxes, and other articles of use. At the Great Exhibition of 1851 several models of public buildings, monuments, &c., were exhibited, formed of Cannel Coal.

The above coals are those most commonly burned. Their goodness for heating is tested by the quantity of water they evaporate. The following are the results of some recent experiments :--

From which it will be seen that the heating power of anthracite nearly doubles that of some bituminous coals.

Brown Coal, Wood Coal, Lignite, are names given to less perfect varieties of coal than the last. Specimens of these coals have a brownish-black colour, and burn with an empyreumatic odour.

On placing sections of Lignite under the microscope, the structure of the wood of the plant forming it can be readily detected. This is not the case with the other kinds of coal, where, although the woody fibre can be frequently made out, it has evidently undergone considerable change. Professor Quekett, on this ground, proposes to confine the term Coal to those fossil or mineral substances alone which are evidently made up of the woody tissue of plants. He maintained that the Torbane mineral was not coal, on the ground that it was not composed of the debris or remains of vegetable woody tissue. Although woody and vascular tissue can be seen in the Torbane mineral, Professor Quekett maintains that this has been accidentally introduced, and that no true vascular or spiral tissue is found in coal. The term Brown Coal is frequently applied to coal more recently deposited than that of the great coal-beds of the world, and this quite independent of its structure or any peculiarity in combustion. Lignite is also a term applied to the semi-carbonised forms of wood deposits. Most of these varieties of coal contain a large quantity of which are frequently found in deposits later than those of the coal water, and the quantity of matter given off at a moderate heat by distillation is at least equal to that of the carbon contained. "Dysodil is a yellow or grayish highly laminated substance, often found with lignite, and burning vividly, and spreading an odour of assafoetida." (Ansted.)

It sometimes occurs in elongated reniform masses, and sometimes in Jet is another variety of coal belonging to the bituminous series. the form of branches with a woody structure. It is soft and brittle, with a conchoidal fracture. Its specific gravity is but little greater than that of water. It is opaque, of a velvet-black colour, and has a Prussian amber-mines in detached fragments. It is sometimes washed brilliant and resinous lustre. It is found in Saxony, and also in the up on the shores of Great Britain. The finer sorts are used in the

manufacture of ornaments and trinkets of various kinds. The coarser sorts are burned as fuel. It gives out when burned a greenish flame and a strong bituminous smell, and leaves a yellowish ash. It contains about 374 per cent of volatile matter.

For an account of the origin of Coal, an' the beds of Coal on the surface of the earth, see COAL FORMATION.d COAL PLANTS.

Geology, Mineralogy, and Physical Geography; Memoirs of the Geological (Dana, Manual of Mineralogy; Ansted, Elementary Course of Survey of Great Britain and of the Museum of Practical Geology; Gregory, Hand-Book of Organic Chemistry; Reports of Juries of Great Exhibition; Catalogue of the Great Exhibition; Proceedings of the Microscopical Society; Microscopical Journal, 1854.)

COAL FORMATION. That part of the Carboniferous System of Rocks which lies above the Limestone Shale and Mountain Limestone is called the Coal Formation. The deposits constituting this formation consist of a series of alternating beds of sandstone and shales, between which lie beds or seams of coal. These deposits generally lie upon a rock called the Millstone Grit. The following is a synopsis of the Carboniferous System as it is developed in two of the most typical coal districts in the British Isles. These two districts are South Wales and Derbyshire.

In South Wales we get, resting on the Old Red-Sandstone, a band of about a hundred feet in thickness, of black fossiliferous shale, called the Lower Limestone Shale, over which are beds of thick limestone, called the Mountain or Carboniferous Limestone. The following is a synopsis of the whole formation, taken from the published sections of the Geological Survey of Britain' (ascending order) :— 1. Lower Limestone Shale, about 100 feet.

2. Carboniferous Limestone; limestone, with occasional partings of black shale; from 500 to 1500 feet.

3. Millstone Grit, or Farewell Rock; white quartzose sandstone and conglomerate; 300 to 600 feet.

4. Coal-Measures; a great series of alternations of sandstones and shales, with occasional beds of coal; from 8000 to 12,000 feet in total maximum thickness.

In the Derbyshire district we get the following groups or series :1. Mountain Limestone; the base of which is not exposed, consisting principally of thick limestone, occasionally interstratified with black shales, and exceeding 1200 feet.

2. Limestone Shale; black shales, with their interstratified limestones; in some places 400 to 650 feet.

3. Millstone Grit; strong sandstones, with occasional small conglomerate, interstratified with shales and a few small beds of coal; about 1700 feet.

4. Coal-Measures; alternations of sandstone and shale, with beds of coal and ironstone; total thickness, 2700 feet and more.

Proceeding from the Derbyshire district towards the north, a gradual change takes place in the Carboniferous Formation in such a way that it becomes more and more a series of Coal-Measures from top to bottom. The Millstone Grit is never anything more than the lower part of the Coal-Measures in which beds of strong sandstone occur. These as we proceed north become more and more split up and interstratified by beds of shale and occasional beds of coal. The Limestone Shale, too, of Derbyshire farther north becomes split up by beds of gritstone and limestone, and still farther north by beds of coal. Lastly, the Mountain Limestone itself becomes split up and interstratified first by beds of shale, then by beds of shale and sandstone, and lastly, on the borders of Scotland, by shales, sandstones, and coals. In the midland counties of England-namely, in Leicestershire, Warwickshire, Staffordshire, and Shropshire-the Carboniferous Formation consists simply of the upper group of the formation of the Coal-Measures. Little patches of Mountain Limestone are found below them in one or two spots in the first and last named counties; but usually the Coal-Measures rest directly and unconformably on Silurian and still older rocks. In Staffordshire several beds of coal come together by the thinning out of the intermediate measures, and make a mass of coal which in some places is upwards of 30 feet thick, in from 10 to 13 beds.

In Scotland the Carboniferous Formation admits of no subdivisions into groups. Immediately above the Old Red-Sandstone are CoalMeasures containing beds of coal, over which are thick encrinital limestones interstratified with shales, so that no single mass of limestone is more than 40 feet thick. The whole series of Carboniferous rocks in Scotland is said to be upwards of 6000 feet thick, the whole being Coal-Measures with interstratified beds of limestone in the lower portion, representing the Mountain Limestone of England. The whole series is composed of materials in the following proportions :

Limestone Coal. Clay

40

13

28

2. Limestone Group; crinoidal, dolomitic, and productus limestones, with chert and anthracite.

3. Coal-Measures; shale and sandstone, with coal.

The formation is found also at St.-Etienne in central France, where it appears to consist of conglomerate and sandstone below, and shale and sandstone above, with beds of coal.

In Westphalia there are black shales below, passing up into black limestones, and those into lighter-coloured limestone, which are covered by black shales and sandstone in which beds of coal occur. In Russia there are, according to Sir R. Murchison, two types of the formation. The northern type consists of (ascending order):1. Sands and Shales with coal.

2. Dark-Gray Productus Limestone, Yellow Magnesian Limestone, White Limestone of Moscow, shale and sandstone, and gray, white, and yellow limestone.

3. Limestones, calcareous grits, and flagstones capped by conglomerate. In this type the coal is confined to the base of the formation. The southern type consists of :—

1. Sands and Shales without coal.

2. Productus Limestone with shales, sandstones, and thin limestones, with many beds of coal.

3. Limestone, calcareous grits, and flagstones, with traces of coal, capped by sandstone containing coal plants.

In this type the most coal occurs about the centre of the formation. The above remarks, taken from Mr. Jukes's admirable 'Introduction to Physical Geology,' will serve to show the relation of the deposits of Coal to the other rocks and substances with which it is found associated. The Coal-Measures above referred to occupy definite and limited areas of somewhat considerable extent in various parts of Europe, Asia, America, and the islands adjacent. The following is an estimate of the annual production of coals in various parts of the world as given by Professor Ansted:

COAL-FIELDS.

4,000,000 (3)

Islands.

1. Northumberland and Durham District. Newcastle Coal-Field

2. Cumberland, Westmoreland, and West Riding of Yorkshire :

500,000

18

Small bands and nodules of clay-ironstone are found occasionally in all the shales and clays of the Carboniferous rocks of England, Scotland, and Ireland; but though of economical value, they are not of great geological importance.

In Ireland the Carboniferous rocks consist in the south and west of two subdivisions-Carboniferous Limestone and Coal-Measures. The Carboniferous Limestone, the maximum thickness of which is about 3000 feet, is locally again subdivided into three parts-A. Lower Limestone. B. Calp, a series of dark limestones, interstratified with black shale. C. Upper Limestone. The Coal-Measures consist of alternations of shale and sandstone, with a few thin beds of coal principally anthracite or culm, and have a thickness of more than 2000 feet in the Queen's County. In the north of Ireland the Carboniferous rocks seem to assume more of the type of those of Yorkshire and the north of England. The Coal-Measures are still confined to the upper portion; but the lower part seems to consist of alternations of shale and sandstone with various thick beds of limestone, so that it may be doubted whether the subdivisions of the Carboniferous Limestone of the centre of Ireland can be accurately traced into the north or north-west.

The Carboniferous Formation of Belgium admits of a three-fold subdivision (ascending order) :

1. Arenaceous Shales; gray shales, limestones and pisolitic iron-ore, over which are gray sandstones and anthracite.

Sebergham (Cumberland)
Kirby Lonsdale

3. Lancashire, Flintshire, and North Staffordshire :

Lancashire Coal-Field

2,500 4 17

and

Great Yorkshire Coal-Field
Darley Moor, Derbyshire; Shirley
Moor, Derbyshire

5. Shropshire and Worcestershire :-
Colebrook Dale, Shropshire
Shrewsbury, Shropshire
Brown Clee Hill, Shropshire.
Titterstone Clee Hill, Shropshire
Lukey Hill, Worcestershire
Bewdley, Worcestershire

6. South Staffordshire :

Dudley and Wolverhampton

21,000 17

67

7. Warwickshire and Leicestershire :Nuneaton

Ashby-de-la-Zouch

8. Somersetshire and Gloucestershire :

Bristol.

Forest of Dean

Newent, Gloucestershire