in its main features it resembled the succeeding flora of the Carboniferous period, it seems in all its forms to have been specifically distinct. It was the independent flora of an earlier creation than that to which we owe the coal. For the meagreness of the paper in which I have attempted to describe it as it occurs in Scotland, I have but one apology to offer. My lecture contains but little; but then, such is the scantiness of the materials on which I had to work, that it could not have contained much: if, according to the dramatist, the "amount be beggarly," it is because the "boxes are empty." Partly, apparently, from the circumstance that the organisms of this flora were ill suited for preservation in the rocks, and partly because, judging from what appears, the most ancient lands of the globe were widely scattered and of narrow extent, this oldest of the floras is everywhere the most meagre.

hand, M. Alcide D'Orbigny regards it as decidedly Old Red; and certainly its Sphenopteris and Lepidodendron bear much more the aspect of Devonian than of Carboniferous plants.

LECTURE TWELFTH.

ON THE LESS KNOWN FOSSIL FLORAS OF SCOTLAND.

PART II.

IN the noble flora of the Coal Measures much still remains to be done in Scotland. Our Lower Carboniferous rocks are of immense development; the Limestones of Burdiehouse, with their numerous terrestrial plants, occur many hundred feet beneath our Mountain Limestones; and our list of vegetable species peculiar to these lower deposits is still very incomplete. Even in those higher Carboniferous rocks with which the many coal workings of the country have rendered us comparatively familiar, there appears to be still a good deal of the new and the unknown to repay the labor of future exploration. It was only last year that Mr. Gourlay* of this city (Glasgow) added to our fossil flora a new Volkmannia from the coal field of Carluke; and I detected very recently in a neighboring locality (the Airdrie coal field), though in but an indifferent state of keeping, what seems to be a new and very peculiar fern. It presents at first sight more the appearance of a

*Now, alas! no more. In Mr. Gourlay the energy and shrewd business habits of the accomplished merchant were added to an enlightened zeal for general science, and no inconsiderable knowledge in both the geologic and botanic provinces. The marked success, in several respects, of the brilliant meeting of the British Association which held in Glasgow in September, 1855, was owing in no small measure to the indefatigable exertions and well calculated arrangements of Mr. Gourlay.

described.

Fig. 126.

In this richly ornamented Stigmaria the characteristic areola present the ordinary aspect. Each, however, forms the centre of a sculptured star, consisting of from eighteen to twenty rays, or rather the centre of a sculptured flower of the composite order, resembling a The mimeadow daisy or sea-aster.

STIGMARIA.

nute petals,- if we are to accept the latter comparison,-are of an irregularly lenticular form, generally entire, but in some instances ranged in two, or even three, concentric lines round the depressed centre of the areola; while the interspaces outside are occupied by numerous fretted markings, resembling broken fragments of petals, which, though less regularly ranged than the others, are effective in imparting a richly ornate aspect to the whole.

Fig. 127.

Ever since the appearance, in 1846, of Mr. Binney's paper on the relations of stigmaria to sigillaria as roots. and stems, I have been looking for distinguishing specific marks among the former; and, failing for a time to find any, I concluded that, though the stems of the sigillarian genus were variously sculptured, their roots might in all the species have been the same. The present rich specimen does seem, however, to bear the specific stamp; and, from the peculiar

THE SAME, MAGNIFIED

character of the termination of another specimen on the