will be found to remain throughout the year, if carefully looked for. I do not say that the warblers which are reared in any one locality remain there permanently; but if they really leave in September, as they are said to do, their places are taken by others whose flight has extended perhaps beyond Scotland altogether, and whose return journey has been cut short by the temptations of what we now know to be their winter diet.

VII.-On Spiders, with some additions to the Scottish lists.
By Mr HENRY C. YOUNG.

Having recently captured several species of spiders which are not noted in any published Scottish list, I have brought them forward this evening in order that they may be recorded, as I find it will be some time yet before the list which I am preparing of the spiders of Clydesdale for publication by this Society is ready.

Argyroneta aquatica, Clerck. This species, the well-known "Water spider," has not, I believe, been previously recorded for Scotland, although it was known to occur. Its peculiar habit of constructing its habitation beneath the surface of the water makes it conspicuous among all the members of the class, for although there are several spiders which, when in pursuit of prey, have no hesitation in descending beneath the surface, there are none which habitually remain there. The specimen before us was obtained from Possil Marsh, and I have not succeeded in finding it in any other locality here. It occurs in England as far north as Durham, and is found in nearly every country on the Continent of Europe.

Linyphia frenata, Reuss-Wider. I have several examples of this species from the neighbourhood of Glasgow. By Blackwall it was considered rare in England; and Dr Thorell notes it as rare in Russia and Sweden. Menge, however, says it is common in the vicinity of Danzig.

Linyphia montana, Clerck. This spider is more common than the preceding spider, and is generally distributed in Europe. The specimens before us are from Dunoon and Rannoch.

Linyphia nebulosa, Sundevall. I have obtained a number of specimens of this species from a building in Glasgow. It is very rare in England; and is not a common species on the Continent; having been met with sparingly in Germany. I have examined 30 or 40

specimens, and find considerable diversity in the colour, but after a little practice there is no difficulty in their identification. The web is of considerable size, and consists of an irregular network of fine lines, usually horizontal. Not uncommonly it is placed close beside the snare of the house spider (Tegenaria Derhamii, Scop.), and each insect seems to respect the prey which falls on the other's web, but I have noticed on more than one occasion that when Linyphia nebulosa trespassed on the web of its larger neighbour, it was promptly seized and devoured.

The other spiders I exhibit, although not new to Scotland, are yet of interest.

Chiracanthium carnifex, C. Koch, I found in abundance on Craigmaddie Moor last autumn. The cocoons were of considerable size, and being of white silk, and fastened to the tops of the ling heather (Calluna vulgaris), they could be seen from a considerable distance; and at one place the moor was dotted all over with them, looking not unlike the heads of the cotton grass (Eriophorum). I had previously noticed the same appearance in Glen Rosa, Arran; but then it was the cocoons of Epeira cornuta, Clerck, which were attached to the rushes. In Arran I also got a specimen of Chiracanthium nutrix, West., and found a few females of Drassus lapidicolens, Walck., by the side of the road from Brodick to Lamlash: these latter were under stones beside their large lenticular egg-bags.

Under the name of Philodromus lineatipes, Cam., a new species was described in the "Annals and Magazine of Natural History" for February last. This description was made from an immature specimen in the possession of Mr Cambridge; but, in a small collection of spiders made for me in Perthshire by Mr J. J. King, I found several adult females of this species; and it will consequently require to be figured and described anew from the adult specimen.

VIII-On the larvae of the Tenthredinidae, with special reference to Protective Resemblance. By Mr P. CAMERON.

In this paper the author discussed the question of the colours of Caterpillars, with special reference to protective resemblance. Protective resemblance, he pointed out, was of three kinds. In one case the larvae were protected by the resemblance of their

bodies to the food plants, so that in this way they were not easily noticed, while it was found that larvae of this class were readily eaten by birds and other animals. On the other hand, larvae which possessed noxious properties were so coloured and marked as to be readily seen; and these, too, fed openly. A third class again escaped destruction by their curious and grotesque shapes, although otherwise they were harmless. Proceeding to apply this theory (which had been only hitherto done to the caterpillars of lepidoptera) to the larvae of sawflies, Mr Cameron said that the flat larvae which fed on the upper side of the leaf were green, but as they ate only the upper epidermis, the leaf in this way became quite white, which rendered them visible, while they gave out either a foul smell, or were covered with a resinous exudation. The flat larvae which fed on the lower side of the leaf ate the leaf through and through, and possessed no bad qualities. Again, with the margin feeders innocuous larvae were green, and if they had any markings these took the form of white or pink continuous lateral or dorsal lines, which, no doubt, represented shadow lines. They also in feeding followed the outline of the leaf or the portion eaten out with their bodies which were closely pressed to the edge. Noxious larvae, on the other hand, were marked with contrasting colours and marked with various irregular markings or lines, while they fed with the after part of the body extended in the air. Alluding to the habit these larvae have of keeping their bodies in a state of agitation, Mr Cameron suggested that this was for the purpose of keeping away ichneumons, a view confirmed by his having seen an ichneumon driven away by the larvae of Croesus septentrionalis, by actively whipping their bodies. Various individual cases of protective resemblance were mentioned in the paper, and allusion was made to some of the active and passive means of defence possessed by different larvae.

X.-On two new species of Carboniferous Polyzoa. By Professor JOHN YOUNG, M.D., and Mr JOHN YOUNG, F.G.S.

[Read October 30th, 1877. ]

In a former Part of the Transactions of this Society, Vol. II., p. 325, we described seven species of what we considered to be new forms of Glauconome, from the Carboniferous limestone

strata of Western Scotland, leaving at that time two other forms for further determination. One of these was a stout form of Glauconome, closely allied to the species which we have named G. retroflexa, but differing from it in the number of cell pores between a given number of branchlets, and in one or two other points of external structure. The other form, from the fragments then found, we also believed to be a species of Glauconome, allied by its double cell pores to our sub genus Diplopora. Of both species better preserved specimens have since turned up, and of the latter a small frond has been found which shows that it was fenestrated in its upper portion, and agreeing in general characters with the Carboniferous forms of Synocladia, in which genus we now provisionally leave it; not being, however, quite satisfied that the characters of the Carboniferous and Permian Synocludia are exactly the same.

GLAUCONOME ROBUSTA, n. sp.

Polyzoary erect, slightly flexuous, bipinnately branching at irregular intervals. Branchlets opposite, or slightly sub-alternate, bent towards obverse face, seven in one quarter inch. Cells oval, alternate, about their own length apart, sixteen in one quarter inch, bounded on main branches and branchlets by a prominent, rounded, tuberculated keel, which gives to the cells a buried appearance. Tubercules on keel large, irregularly placed, seven to eight in one quarter inch. Obverse face finely striato-granulate, ornamentated with numerous irregularly scattered small tubercles.

Of the several species of Glauconome found in the Carboniferous limestone strata of the West of Scotland, this form is the most robust in its manner of growth. In size it corresponds with G. grandis, M'Coy, but is easily distinguished from that species by the smaller number of cells between the branchlets, and by its strongly tuberculated keel. From G. retroflexa it is distinguished by its stouter branches, the wider position of the tubercules on the keel, and the more numerous cells in proportion to the branchlets.

Localities: Lower limestone shales of the Beith and Dalry districts in Ayrshire, in fragments of fronds from one to three inches in length. Brockley, near Lesmahagow, in fragments in the lower limestone shale. Upper limestone series, Gillfoot,

Carluke, fragments in the shale. Rather a rare species in most of the localities.

SYNOCLADIA (1) SCOTICA, n. sp.

Polyzoary erect, consisting of a main stem with rounded raised keel, slightly tuberculated, and with secondary branchlets that in the upper portion of the frond unite and become fenestrated. Branchlets sub-alternate, five in one quarter inch on lower portion of frond. On upper portion, where the branchlets unite, they form irregularly shaped fenestrules. Cells on the main stem and branchlets slightly oval, more than their own diameter apart, with the margins slightly raised; one cell at the base of each branchlet, and three between; twenty in one quarter inch. Secondary cell pores small, about one fourth the diameter of main cells; one, very rarely two, above and in line with each main cell, and about its own diameter apart, the margins slightly raised; there are also a few scattered small pores on the obverse face. Both faces striated longitudinally.

This species was first known to us from fragments found by Dr Rankin in the Gillfoot limestone shale, Carluke. At that time, as already stated, the fenestrated character of the frond was not known, and we were inclined to place it with Glauconome in our sub-genus Diplopora, but since that time we have found a small frond amongst some shale sent us by Mr John Smith, Eglinton Iron Works, Kilwinning, from the Garple Burn, Muirkirk, which shows that while the polyzoary commences with a central stem and secondary branchlets, as in Glauconome, yet towards the upper portion of the frond these unite and form a fenestrated frond like that seen in Synocladia carbonaria, Etheridge, jun. Our species differs from it, however, in the regular number of cells between the branchlets on the main stems, in its distinctly striated celluliferous and reverse faces, and in having the small secondary cell pores more in line with the main cells. In S. carbonaria these small cell pores are seldom in line with the main cells, being sometimes below or above, sometimes on the keel or dissepiments, or irregularly scattered about.

Localities: Upper limestone shales, Gillfoot, Carluke; Garple Burn, Muirkirk; in both localities it is very rare.