position of the seven sections, the extent of the blue shale, or leaf-bed, together with that of the lower series of clay-galls (small) in the sands, and of the higher (larger) rolled lumps of clay on the bed of shale. Fig. 4. Sections Nos. 5, 4, 3, 2, 6, & 7 in their order.

Nos. 6 & 7 here take the place of Section No. 1. ·

DISCUSSION.

Mr. WHITAKER said that this careful noting of local features in such very varying sections was of great value, and hoped that geologists would continue to study the sections near Reading. The occurrence of clay-galls, or rolled pieces of clay, was interesting; some of them were, he thought, certainly derived from the destruction of previously existing beds; but others may possibly have been only isolated patches of some attenuated clay bands. Good examples of rolled clay may be seen on any clay shore, as at Sheppey and elsewhere.

Prof. SEELEY stated that he had noticed the lumps of rolled clay at Reading, and that he had seen similar balls of clay derived from the Kimmeridge Clay in the marine gravel at Hunstanton. With regard to the "bottom-bed," he was inclined to believe that it constitutes an abnormal form of the Thanet Sands, being composed of quartz-sand, whilst the sands of the upper beds are mainly derived from flint.

Mr. EVANS remarked that the denudation and reconstruction of beds seemed to be due to alterations of level. It was more surprising, at first sight, that the Oyster-beds, with their accompanying overlying strata, could be traced over areas so wide apart, than that even many local denudations and reconstructions should be observable. Still these latter furnished important evidence as to the history of the deposits.

Prof. RUPERT JONES explained that the large clay-galls, with and without enclosed flints, in the sand over the blue clay, lay about in great numbers, having been exposed and left by the workmen in moving the sand last summer. In the case of the smaller claygalls at a lower level, the associated drifted flints, lydite and lignite, supported the idea of their having also been derived from other beds.

31. On the REMAINS of a FOSSIL FOREST in the COAL-MEASURES at WADSLEY, near SHEFFIELD. By H. C. SORBY, Esq., F.R.S., F.G.S., Pres. R.M.S. (Read April 28, 1875.)

In order to make the ground at the back of the South-Yorkshire County Lunatic Asylum more level, a considerable amount of coalmeasure sandstone and shale was excavated in the autumn of 1873; and this exposed to view a number of the stumps of large fossil trees. My attention was called to them by my friend, Mr. W. P. Milner, one of the visiting magistrates; and soon afterwards I attended a meeting of the Visitors at the asylum, and pointed out on the spot the desirability of preserving some of the larger and better specimens in situ, so that their position and relation to the strata might always be seen. It was then at once resolved that two small sheds should be erected to protect the trees from the weather; and I am glad to say that this has been carried out in a most satisfactory manner. They have been made of wood, with felt roofs; and they have a number of glazed windows, so that the fossils can be easily seen, even from the outside, or more completely examined by procuring the keys at the Asylum. We may thus hope that these interesting remains will be preserved in a satisfactory state for many years to come.

The manner in which they occur is so similar to what has been described by Bowman*, Binneyt, Beckett‡, and others, that I need not occupy the space of our Journal in repeating what has been already published, but may say that the facts bear out extremely well the views enunciated by Bowman, and seem to show that the

Fig. 1.-Section showing the position of the stumps in the Fossil Forest at Wadsley near Sheffield. (Scale 1 inch to 40 feet.)

N.E.

S.W.

trees grew in what is now a bed of earthy, clay-like shale, and then died and decomposed down to the level of the surrounding mud, leaving hollow stumps, subsequently filled with the sand now constituting the superjacent bed of sandstone (fig. 1). Both this and

* Ed. New Phil. Journ. 1841, vol. xxxi. P. 154.

+ Phil. Mag. 1844, xxiv. p. 165.

Quart. Journ. Geol. Soc. vol. i. p. 41.

the subjacent clay-like shale are not of a nature suitable for the preservation of minute markings; and it is only just possible so to recognize the Sigillarian character of the trunks and the Stigmarian markings on the roots as to feel certain that they are Sigillariæ. Their general characters will be seen from the following drawing of the largest and best-preserved specimen (fig. 2). It is about

Fig. 2.-Fossil Stump of Sigillaria at Wadsley near Sheffield. (Scale inch to 1 foot.)

5 feet 2 inches in diameter, with almost as flat a surface as if it had been cut off with a saw. There are eight large roots, which when exposed are seen to bifurcate and extend in some directions for about 6 feet, after which they are either hidden or have been destroyed, so that their total length is unknown. By the side of this stump is a large prostrate trunk, as shown in the figure. These specimens are enclosed in one of the sheds. The total number of stumps which were exposed was about ten, spread over a distance of 40 or 50 yards. All that can be properly seen have either eight roots when the stump is large, or only four when small and partially grown, which agrees with what has been previously observed in similar cases. Two fine specimens occurring near together have been covered by a single larger shed.

What appears to me to be one of the most interesting facts connected with these trees is the evidence they furnish with respect to the direction of the prevailing winds at the time when they grew. A careful examination of the trees now growing on the exposed moorland hills of the district shows that when they are young the prevailing westerly gales often make them incline towards the east; and in doing this, the roots on the west side are pulled straight and made to run more horizontally, whilst those on the east side are pressed down and made more nearly vertical; and these characters remain permanently when the tree has grown to a large size. Now this sort of difference on different sides can be recognized more or less decidedly in the case of all the stumps seen in the Wadsley fossil forest, but is especially well marked in the largest and bestpreserved specimen (fig. 2); and it appears to me a very interesting fact that the direction of the prevailing high winds at the Carboniferous period thus indicated is almost exactly the same as that at the present period, as shown by the same facts seen in trees now growing in the neighbourhood.

DISCUSSION.

Mr. MOGGRIDGE inquired whether the trees were rooted in solid rock or in earth. Near Swansea trunks of trees were imbedded in solid rock and upright.

Mr. GRANTHAM inquired whether the trees were broken short off, leaving rugged tops, and whether any trunks were found.

Prof. SEELEY said that in the Fens we find erect stumps of Yew, Oak, and Pine, and that the stumps never rise above the surface of the peat. Sometimes a bed of marine clay overlies the peat, and fragments of the trunks are found scattered in it, showing that the trees stood in the sea and died there.

Mr. SORBY said that the lower parts of the roots are in soft clay shale, and the upper portions in hard sandstone. He thought that the trees were submerged, and that their trunks decayed down to the level of the water, the surface of the stumps being remarkably level, as though cut off with a saw.

32. On the Axis of a DINOSAUR from the WEALDEN of BROOK in the ISLE OF WIGHT, probably referable to the IGUANODON. BY HARRY GOVIER SEELEY, Esq., F.L.S., F.G.S., Professor of Physical Geography in Bedford College, London. (Read May 26, 1876.) THIS vertebra was collected for the Woodwardian Museum of the University of Cambridge by Mr. Henry Keeping, and catalogued in my Index to the Aves, Ornithosauria, and Reptilia' (p. 81) as the axis of a Dinosaur. The specimen is perfect, and but very slightly crushed from side to side. It measures 3 inches in length, from the termination of the dentata to the posterior articular face of the centrum. The vertebra has a small neural arch, and measures 34 inches from the base of the centrum to the top of the neural spine.

The centrum is depressed, and anteriorly measures 1 inch deep from the neural canal to the base, and is 2 inches wide over the articular surface. This surface, below the dentata, is nearly vertical (fig. 1, a), and forms more than a quarter of a circle (fig. 2, a). In the middle of the base of the centrum a wedge-bone ossification is anchylosed, as in birds (fig. 2, a), and projects forward for about a

Fig. 1.-Axis of a Dinosaur from the Wealden of Brook.
(Side view. Half natural size.)

b. Articular band.

a. Anterior articular surface. c. Non-articular surface. d. Dentata. e. Posterior articular surface. f. Anterior zygapophysis. g. Diapophysis. h. Parapophysis. i. Neural ridge. 7. Posterior zygapophysis.

quarter of an inch. The vertical articular surface has its superior (or interior) outline nearly parallel to the circumference of the bone (fig. 2), and is rather more than inch deep. Confluent with this area, and between it and the underside of the dentata, which it occupies for half an inch, is an articular band margined by a somewhat sinuous anterior border (fig. 1,6), which is inch wide in the