all the pieces of shells with which it is overlaid being placed along the inner frame of the tube in pentangular rows.

No 10, Nothria conchylega (Sars), is less symmetrical, the tube being greatly depressed and rugged at the edges, with a coarse and irregular aspect; but when we examine it with care we see a strict application of means towards an end. It will be observed that all the building materials (fragments of shells) have been laid down in the under row with the concave side up, and in the upper row with the concave side down, thereby forming a flat tube for the lodgement of the animal. It will be noticed that the pieces with which it is built are mostly of a considerable size, and so laid as to secure the greatest possible strength, which is accomplished by laying one piece over the other in such a way that an upper piece will cover the joining of two under pieces, a process familiarly known to builders by the name of "breaking band." This again anticipates one of the universal principles both of ancient and modern architecture.

There are many tube builders whose materials are laid less orderly, and where the cement is more gelatinous and yielding in character than in the cases we have noted, as in Nos. 11, Lanice conchilega (Pallas), and 12, Thelepus circinnatus (Fabricius). There are others, as No. 13, also Lanice, where the fine sand forming the tube is held together by a very thin mucous secretion of the animal. These tubes are often very long; some that have come under my own observation being formed in the following way:-The animal gathered a ring of sand round its neck, where it was supplied with the requisite amount of mucus to secure cohesion; from thence the ring was carried down to the posterior end of the body. Other rings were formed, and followed each other in the same way till the tube was completed.

Some species of these annelids are solitary, while others are gregarious. On the south-east side of Luce Bay the interstices of the shingle between tide-marks are closely filled up with the arenaceous cases of a colony of Sabellaria alveolata, in some places fringing the sides of pools, and at other points covering the flat rocks with a solid crust. It may be remarked that this annelid is not always gregarious, nor in all cases confined to the tidal belt, as I have often brought it up in the dredge at Cumbrae in twos and threes adhering to the valves of Pecten opercularis, from a depth of twenty-five fathoms.

It is found that each species selects that kind of material which accords with its own particular habits; but the departure from the common rule is often considerable, where the supply of proper materials are not within reach. In such cases they avail themselves of the next best, and failing such, some of the species fall back on the resource of constructing a tube solely from their own secretion. These shifts often give the structure a very different aspect from its common appearance, and one that is ready to mislead as to the true character of the occupant.

But whatever straits or shifts they may be driven to, or whatever kind of materials they may use, whether the consolidation of soft mud into tubes, the picking out of fancy stones to cover the walls of their habitation, the laying of each piece so as to "break band," the overlapping the materials of the walls like the slates on a house, the construction of the edifice with fine mosaic work or with plain rubble, the same line of structure of each species is rigidly adhered to.

Mr John Young, F.G.S., stated that probably never had such an interesting series of tube-building annelids been exhibited before any Society in this country as those laid before the meeting on this occasion, and they were the more interesting from the fact that they had all been obtained by Mr Robertson's own dredging, chiefly from the Frith of Clyde. The group had hitherto been little studied, and probably many other species await further exploration in the seas around the Scottish coasts. Mr Young hoped that Mr Robertson would still continue his researches among the less known marine fauna, as only from the investigations of able naturalists important information like. that embodied in Mr Robertson's paper is to be obtained.

DECEMBER 28TH, 1875.

Mr James Ramsay, Vice-President, in the chair.

Mr Arthur Pratt was elected an ordinary member of the Society.

Mr J. B. Murdoch called the attention of the meeting to the death, after a long illness, of Mr James H. Pearson, who had for many years been a member of the Society. He had for a

lengthened period been in delicate health, and consequently unable to take such a prominent part in the proceedings as his interest in Natural History subjects prompted him to do. He was an industrious and zealous worker in entomology, and gave promise, had his life been prolonged and health granted him, of becoming distinguished in that branch of science.

Reference was also made to the death of Mr James Thomson, Curator of the City Industrial Museum, Kelvingrove Park, who had been an active and valuable member of the Society since his first appointment to the office which he held. He was ever ready to promote the interest of the meetings, by the exhibition of specimens, or by taking part in any discussion that might arise, and his opinion was often of value, especially on any point connected with ornithology, which was his favourite study, although he took a lively interest in all branches of Natural History. By his urbanity and obliging disposition, he gained the esteem of all with whom he came in contact, and in the occasional meetings of the Society held in the rooms of the Kelvingrove Museum, he always endeavoured, even at much trouble to himself, to promote the comfort and convenience of the members.

The Secretary was instructed to record in the minutes the feeling of regret with which the meeting had heard of the death of these two esteemed members, and to furnish an extract of the minute to the nearest surviving relatives of the deceased, with an expression of sincere sympathy in their bereavement.

SPECIMENS EXHIBITED.

Mr John Kirsop exhibited a collection of ferns from the province of Auckland, New Zealand. The specimens, which were mounted with great taste and care, numbered over seventy, and embraced examples of nearly all the genera of Filices.

The Chairman, in a few remarks, pointed out the peculiar character of the New Zealand flora, which comprised a larger variety of ferns than was known in any other country, many of the species being confined to those islands. Mr George J. Combe also made some general observations on the collection.

Mr Peter Cameron exhibited a large collection of insects, embracing of Ichneumonidae-specimens of the female of Eumesius crassicornis, Grav., from Kingussie, and from the same locality, an undescribed species, proposed to be named Limneria

croceipes, and distinguished by having a black body, with bright yellow coxae, tibae, and tarsi, and black femora; also Bassus flavolineatus, Gr., found in Cadder Wilderness. Of Tenthredinidae Mr Cameron showed Nematus hortensis, Hartig, from the London district, the larva feeding on the acacia; also Cladius Drewseni, Thoms., from England and Scotland, the latter species being an addition to our list.

Mr George Donaldson exhibited the nest of the Trap-door Spider from California, which country he considered to be the head-quarters of the species, as it is there met with in large numbers. He described the mode in which these nests are constructed. A well of five or more inches in depth is sunk in the ground, and inside of this the nest is formed of red clay, and lined with a fine silk-like material obtained from the secretions of the spider. The door or trap is a marvel of ingenuity; it cannot be opened from the outside, and serves not only for catching the prey of the animal, but affords a secure refuge from the attacks of more powerful enemies.

Mr Donaldson also exhibited a piece of a clay-like substance which is largely eaten by the Indians, and of which they are so fond that a supply is invariably carried with them when journeying. It appears to be a fresh-water deposit, and to be largely composed of diatoms. He also showed a number of objects of interest from Figi, among which was a necklace worn by the natives, and made up of the teeth of the sperm whale, which they obtain from the whaling vessels in exchange for palm oil and other native produce.

PAPERS READ.

I.-Notes on the occurrence and distribution of Spirifera trigonalis, and its varieties in the Limestone Struta of the Coal-fields of the West of Scotland. By Mr JOHN YOUNG, F.G.S.

During the very long period represented by the Old Red Sandstone series of Scotland, no evidence of purely marine conditions has yet been discovered over the area of country now covered by rocks of that formation. Throughout a thickness of several thousand feet of strata, the characteristic organisms met with are fishes, of which the greater number belong to the ganoid order, a group finding its nearest living representatives in the rivers and fresh-water lakes of the globe. Besides fishes, the

only other organisms met with in the Scottish Old Red are crustacean and plant remains. Of the crustacea, the genus Estheria affords evidence of fresh-water conditions. We find no remains of corals, crinoids, or molluscs, such as characterize the marine strata of the Devonian formations of other countries, and which are believed to be the marine equivalents in time of the Old Red of Scotland. The evidence afforded by the organisms, and by the prevailing red colour of the formation, favours the assumption that the whole series of beds were accumulated in a great freshwater lake or lakes, but in which the waters may have been at times slightly brackish.

In the east of Scotland, in the calciferous sandstone series that overlies the Old Red Sandstone, we meet with, at intervals in the strata, evidence of the return of the sea, as indicated by the occurrence of certain characteristic marine fossils of the Carboniferous limestone period, which there make their appearance for the first time, so far as known to us.

In the west of Scotland, the calciferous sandstone series forming the lowest division of our Carboniferous system, is represented by a series of fresh-water strata, known as the Ballagan group, in which no characteristic marine fossils have yet been found. Overlying this group, we have a great thickness of trappean or volcanic rocks, which build up the Campsie, Kilpatrick, Renfrew, and Ayrshire hills; these in their turn are succeeded by strata belonging to the lower Carboniferous limestone period, in which we have abundant evidence of those alternate changes of conditions -from lakes, with fresh-water strata, to land surfaces, with forests of vegetation, as represented by our coal-seams; and from these to deep sea bottoms, with their growths of corals, crinoids, shells, shark-like fishes, and other characteristic marine forms.

Having stated this much regarding the palaeontological character of the Old Red Sandstone and Carboniferous strata, as indicated by their fossils, I come now to call your attention shortly to a group of the Spirifera, found in the marine limestone strata, belonging to the well-known and common species, Spirifera trigonalis, Martin, and the variety, S. bisulcata, Phil. These two forms present us with several variations in shape, which in some cases seem to be peculiar to certain localities, and to the strata of different geological horizons; and as the species ranges from the lower beds of the limestone series, in the west of Scotland, up to