Order I. Univalves.
THE exuviæ of the once animated inhabitants of the ocean, far surpass, in variety and number, the petrified remains of vegetables. They are arranged into four classes, namely, Shells, Entrochi, Coralloides and Fishes Teeth. The figures referred to for the illustration of these classes, exhibit the natural size of the specimens, from which they were drawn, unless otherwise mentioned.
A SPECIES of the Patella, or Limpet, is found among till, incumbent on lime-stone, in many of the quarries in Kilbride. The specimens sometimes adhere to small stones and fragments of shells. They are generally small, few of them being larger than the draught, fig. 10. pl. XV. The native shell is, for the most part, entire: it is of a bluish colour inclining to black. The apex is placed a little to one side: it is not perforated, but all the casts, where the shell is worn off, have a small slit, apparently occasioned by a thin prominent ridge, on the inside of the apex of the shell, fig. 9. Good specimens are found in Magpie-hill quarry, parish of Stewarton. Limpets are but rarely found in fossil Britain.
ORTHOCERATITES, the Tubuli concamerati of Klein; or, according to Da Costa (Conchol. p. 156.) the “Orthoceros, simple straight conical shells, or nowise turbinated; and gradually tapering from a broad end to a sharp-pointed top, like a strait horn, whence their name. They are chambered from bottom to top, and have a siphunculus, or pipe of communication, from chamber to chamber.” Two species are found in Kilbride: the sulcated, superficie sulcata, fig. 2. pl. XVI. and the smooth, superficie lævi, fig. 3. They are generally in casts. Both kinds, wholly covered with the original shell, are found at Thornlie-bank in the parish of Pollock, formerly the Eastwood. They lie in a horizontal position, in a thick stratum of till. The shell of the smooth kind is of a horny appearance, and a dirty white colour. The sulcated is finely striated in the same direction with the sulci. The shells of both species are very thin, and extremely well polished on the inside. Specimens retaining the shell, ar, in the fossil kingdom, very rare. The greatest number of the specimens are bruised, apparently by some violent pressure, when in a recent state: the bruises are commonly near the bottom, though in some specimens they are almost at the point. The Septa are thin, convex and polished, like the recent Lituus. In some specimens the pipe is thick and rugose. Perhaps this peculiarity is common to a certain part of the pipe in every specimen. Of this peculiar structure I have two examples from Hermyres.1 They are corroded on that side, which, in other specimens, is usually bruised. By this means the internal structure of the chambers, &c. is exposed to view. The pipe is swelled out to an uncommon size; is very thick and rugose, and has the appearance of a string of beads, fig. I. The pipe, as at a, adheres to one side of the shell, and is perforated in the center. Da Costa (conch. p. 156.) mentions a similar specimen, a draught of which he takes from Breynius de polythalamiis. The longest specimen of the Orthoceratites I have met with is 5½ inches: it was mutilated at both ends; the diameter of the thickest was an inch, of the other ¼. Some fragments are nearly 3 inches in diameter.
THIS part of the country affords but few specimens of the Cornua Ammonis, the Nautilites, of Lhwyd; and the Serpent stones of the vulgar. Two varieties are all I have met with in Kilbride. The spires of the one are smooth and round, without any depression or sulci; the specimen is about 6 inches broad. The other, which is nearly of the same size, is likewise smooth, but the sides are flat, and are destitute of sulci. Both kinds were found at Hermyres.
TWO species of the Cochleæ Helices, are all that have been discovered in this place. Casts of the one, having 5 round spires, are found in lime-stone, at Limekilns. The other is never found without the shell, which is of a horny appearance, and consists of 5 spires of a triangular shape, and which are always replete with till. I never found specimens of this variety imbedded in stone. The largest are not above 1½ inch broad, and some of them are very small. They are found at a quarry at Lickprivick, and in many other places in the west of Scotland.
THE shell, fig. 8. pl. XIV. seems to be a chambered Nautilus: it is thin and deeply umbilicated. The specimens frequently retain the shell, which is thin, polished, and of a horny appearance. They are found, though unsparingly, at Lawrieston, &c. One that was found at Thornlie-bank is almost wholly inclosed in the valve of a bivalve shell.
THE shell, fig. 9. is probably a Nautilus; it is of a globose form, and beautifully adorned with fine prominent threads, giving it a kind of striated appearance, and is not chambered. The specimens, for the most part, retain the shell, which is of a whitish colour, pretty thick, and very well polished within. Some are an inch in diameter, others not nearly so big. They are found at Lawrieston.
THE varieties of the Turbo, fig. 1, 5. are not numerous in a fossil state. Of the Terebra, or Turbo clavicula longissima, are two species. One is striated transversely, fig. 7. the other, fig. 11. is striated spirally, and is found in a recent state on all the shores of Europe. The till in which they are enveloped lies between the two strata of lime-stone at Stuartfield and Lawrieston. Many specimens are no thicker than a fine thread, and about ⅟12 of an inch. By a microscope they are found to be equally perfect, and to contain the same number of spires, with the largest specimens. Quære, if they are young shells, how come they to have as many spires as the oldest in the species?
THE Buccinum, fig. 2, 3, 4. does not afford, in Kilbride, many species. Fig. 4. is of a white colour, and transversely striated.
THe Trochus is not plenty. The species which Da Costa calls Buccinum Heterostrophon, or other handed whelk, in which the spires take a direction from the left to the right hand, instead of from the right to the left, like other shells, is sometimes, but not frequently, found, fig. 18. Specimens are met with at Limekilns and Stuartfield quarries. Along with them the species, fig. 10. is sometimes found. It bears a near resemblance to the Umbilicaris.
THE Serpula planorbis may be ranked among the univalves. I have not met with more specimens than two or three, adhering to fragments of shells.
Order II. Bivalves.
Division First. Shells having both valves equal.
THE Cockle, fig. 2. pl. XV. is not frequently found in Kilbride. I picked up some specimens near the Blackcraig. Some found at Thornlie-bank are so perfect that they appear to be living. They are imbedded in Schistus along with Orthoceratites, Buccini, Entrochi, &c.
OF the Multarticulate Cockle, fig. 5, 6. exhibit two species. The hinge, which is observable in the casts only, consists of about 12 teeth on each valve. Both kinds are found at Lickprivick, Shields and Lawrieston. The best specimens I have seen were lodged in till, on the banks of the Water of Aven, near Netherfield, in the parish of Avendale. Some are so perfect that several persons, supposing them to be living, have attempted to open them. The shell, in both species, is white, and commonly in a high state of preservation. The species, fig. 5. is finely striated.
TWO species of the Muscle are found in Kilbride, fig. 5, 6. pl. XVI. Specimens of the former are in casts, and are very rare. Numberless specimens of the latter are imbedded in till incumbent on iron-stone at Mauchlan-hole; and sometimes in the iron-stone itself. They are mostly in single valves, and lie flat in a horizontal position. Whole specimens are found, but rarely, at Lawrieston.
THE marble in Rutherglen, already mentioned, abounds with a vast quantity of the Muscle, delineated fig. 4. Some entire specimens are enveloped in the till, containing impressions of the Pine, formerly described. The shells are commonly entire, and were, probably, produced in fresh water.
THE most uncommon shells in this division are three kinds of what may be called Microscopic. They are, with difficulty perceived, by the naked eye, to be shells. The specimens, when viewed by the microscope, appear to be very perfect: but I have sometimes met with detached valves. None are so numerous as that represented fig. 15. pl. XIV. The shell is of a pure white colour, and retains an extremely fine polish. The figure is greatly magnified. The species, fig. 20. is commonly five or six times larger than the former. The specimens are not nearly so numerous: they are white, and retain a good polish. Some of them exhibit marks of bruises which appear to have been given them in a recent state. The scarcest and most curious is the one delineated fig. 16. Different views of it are given fig. 17, 21. The shell is of a brown colour, and ornamented with minute indentings. The dots in fig. 17. exhibit the natural size of the shell.
THESE very uncommon, and, as far as I know, hitherto undescribed shells are found at Lawrieston and Stuartfield. I have not been able, even after a diligent search, to find them any where else, except in a lime-stone quarry about 15 miles west from Newcastle-upon-Tyne, near the spot where the Roman Wall is intersected by Watling-Street. What I found there was only the variety, fig. 20. and the specimens were very rare. From Kilbride, however, I have made a collection of these extremely small objects of nature, that might furnish abundance of specimens for all the Museums in Europe. they are best exhibited by putting them, in separate apartments, in a small picture frame, with a glass before them. By this means a magnifying glass can with ease be applied to them.
Division Second. Shells having unequal valves.
THE Anomia contains the greatest number of genera, in this division. Fabius Columna, an accurate naturalist, was the first who introduced this name into the system of fossil shells. Finding that many species were not described by writers on Conchology, he called them Conchæ rariores Anomiæ. This name ever since, has been adopted as the nomen proprium of that numerous family of shells. I shall divide them into three kinds. 1. Læves. 2. Striatæ. 3. Echinatæ.
FIRST. Anominæ læves. The species which to appearance is the most simple, is the one delineated fig. 9. pl. XVI. Both valves are conves. Great abundance of bruised ones and fragments are found at Lawrieston. The Floors quarry, near Johnston-Bridge, contains good specimens of this shell. In some the beaks are not perforated. Along with it is found, but not frequently, a species in which the beak is very seldom perforated. The shell is broader than the other; whiter in the colour; not of so horny an appearance, and is destitute of the shallow groove in the under valve.
IN the species, fig. 12. pl. XIV. the beak is never perforated, and the hinge is on a straight line. Most perfect specimens of this shell are plentifully found in a lime quarry, on the east bank of Aven, a little below Strathaven. Elsewhere, as far as I know, they are very scarce.
SECOND. Anomiæ striatæ. To this family belongs the genus represented fig. 6. It is found in great plenty in several places of Kilbride, but the specimens are mostly bruised, as in the figure. They are, in most places, found in the same imperfect state. Some entire ones, however, are found in the Floors quarry, already mentioned.
THE shell, fig. 1. pl. XV. is very beautiful. The specimens from Lawrieston, and some other places of Kilbride, are in fragments, or greatly bruised. The hinge is exactly in the middle of the straight line below the beak. It consists of two teeth in the under valve, which are inserted into two corresponding furrows in the upper. The straight line below the beak is not multarticulated. Specimens, in great perfection, are found at Thornlie-bank: some of them retain the marks of bruises received in a living state.
THE species, fig. 14. pl. XIV. is found in a quarry at Philipshill, and very plentifully in the lands of Treehorn, bear Beith, The one valve is only a little smaller than the other. the specimens are thin; of a white colour; and finely striated. The valves are sometimes detached. Fig. 13. shows the inside of one of them.
THIRD. Anomiæ Echinatæ. By these are understood unequal valved fossil shells that are furnished with spines.
THE smallest and most numerous in Kilbride is the species delineated fig. 4. pl. XV. The under valve is convex, having the contour greatly curved over the upper valve, which is almost level, or a little concave; the whole making a thick semiglobose shell. The spines are few, and regularly placed, and are all on the under valve. They are long and slightly flexible. Their appearance is that of wires of Mother of Pearl, retaining the most finished polish. They consist of two parts. An external covering composed of a great number of concentric lamellæ, extremely thin, and shining like white mica; they constitute about the half of the thickness of the spine. Within that is a white, solid, opaque substance, which composes the other part. The lamellæ seem to be an elongation of the several coats, or lamellæ of the shell, to which the spines adhere, or rather out of which they seem to grow. They were not, therefore, moved by articulations, or cartilages, like the spines of the recent Echini. Many of the fragments are greatly bruised and flattened, which injuries they must have received when recent. They are placed on the under valve in such a manner, as to assist the animal in suspending itself on the surface of the water: they might also be helpful in procuring food, and warding off danger. The specimen from which the figure was taken is very singular. It lies horizontally in a piece of till, in which it was originally deposited. The spines are stretched out as in the figure. The peculiar construction of the inside of the upper valve is exhibited fig. 3.
A SPECIES larger than the former is found in all the lime-stone quarries in the parish. The specimens are commonly about the bigness of an hen’s egg. The beautiful construction of the inside of the upper valve is delineated fig. 12. pl. XVI. The specimen from which the draught was taken was found at Limekilns.
THE largest of all the fossil shells in Kilbride is a species belonging to this genus. The specimens are 5 or 6 inches in length, and of a corresponding breadth and thickness. They are generally imbedded in lime-stone. The colour is whitish, and sometimes faintly tinged with red. By workmen they are called lime-stone oysters. I have seen beautiful specimens of this shell in a quarry near Bathgate.
TO this division belongs a genus, the specimens of which may be called Conchæ pilosæ, rather than Echinatæ. Both valves are entirely covered with very small spines resembling fine hair. They are of the same colour and consistency with the spines above described, and are placed in rows nearly concentric with the beak. The draught, fig. 7. pl. XV. is partly covered with them, and partly not. They are so numerous that a shell of the size of the figure contains upwards of 10000. Their true length, from any specimens I have seen, cannot be ascertained: they so not seem, however, to have reached far beyond the contour of the shell. They lie so closely together that the surface of the shell is entirely concealed from view. The insides of the valves are ornamented with short papillæ, placed in rows like the spines. The specimens of the shells are of different diameters. Some are not above half an inch in length, and others are as large as the figure. they are very sparingly found among till in lime-stone quarries.
PECTEN. Of this family the most delicate and beautiful shell is delineated, fig. 11. pl. XVI. The under valve is very convex; the upper very concave; and both are so thin that they are frequently taken for a single valve: and both are finely striated. In some specimens they can be easily separated from one another without injury; in which case the internal structure is fully exposed to view. They are furnished with very small papillæ, and other configurations, as in fig. 10. This beautiful and rare fossil is found among the till that separates the two lime-stone posts at Lawrieston.
FIG. 13. represents a species that is but rarely found in this country. Some specimens are of an elliptical shape.
THE largest of the pectens, in these bounds, is delineated fig. 19. pl. XIV. Some specimens are larger than the draught; but others are no bigger than a farthing. They are found, but sparingly, at Philipshill quarry. I have seen good specimens in a lime-stone quarry at Darnley.
A VERY small and beautiful pecten is delineated fig. 8. pl. XV. Specimens of this kind are very rare: the one from which the figure was taken was found at Limekilns.
FOSSIL Echini, or the Echinatæ of Hill, are very scarce in this country, I have not observed more species than one, and the specimens were always in fragments; a draught of one is given fig. 7. pl. XVI. Along with them are found, in most of the quarries in Kilbride, a few of the Aculei Echinorum, fig. 8. Some of the fragments are a little larger than the figures; but most of them are less. Good specimens of both are found at Craiginglen, parish of Campsie.