D. LEIGHTON AND E. A. MARTIN,

Saltburn nearly to Boulby Cliff, about 4~ miles east of the town. The model is coloured to indicate the solid-geology, the areas covered by drift being stippled with blue dots. The whole area forms part of the northern limb of a syncline, trending east and west for a considerable distance, the beds every­ where dipping to the south. Owing to the curving nature of the coast the beds on the shore rise and fall as we proceed along the foot of the cliffs, and the lowest of the series forming part of the Ammonites jamesoni and A. capricornus beds of the Lower Lias have extensive outcrops, and many characteristic fossils can be obtained. The cliff at the eastern end of the model gives a com­ plete section of part of the Lower, and the whole of the Middle and Upper, Lias, together with the Dogger at the base of the Oolites, and a little sandstone and shale above this. A brief account was given of the more important beds, including the great seam of ironstone (the Cleveland ironstone), with its characteristic fossils, the large Pecten and A. spinatus. The Jet rock, with A. serpentinus, was also referred to, and an account was given of the old jet workings. The extension of the drift was described, and reference was made to the old pre-glacial valleys, now completely filled with drift, that form such a feature of this part of north-east Yorkshire.

REPORT OF AN EXCURSION TO THE RIVER EFFRA, THE BEULAH SPA, AND THE GRANGE WOOD MUSEUM, .

FEBRUARY 17TH, 1912. By DOUGLAS LEIGHTON, F.G.S., AND E. A. MARTIN, F.G.S., Directors of the Excursion. MEETING at the Crystal Palace High Level Station, a party of IS proceeded along the western side of the horseshoe-shaped ridge which forms the Norwood and Sydenham hills. This prominent outstanding mass of Clay lies between the WandIe and the Ravensbourne, and rises to a height of 378 ft. above O.D. The inner side of the ridge is drained by a small river which has now almost disappeared. This was known as the Effra, and it has had the misfortune frequently to be represented by authors as considerably shorter than it really is. Especially is this the case in a recently published map showing all the London buried rivers. As a matter of fact, from its source to where it joined the Thames near Bridge, it was about four miles long. EXCURSION TO THE RIVER EFFRA. 173 Proceeding to Hermitage Road, the party descended into a small, steep-sided valley, and in a field a small brook was seen which was shown to be a portion of the head waters of the Effra. Rising from springs from the gravel which caps the Norwood­ Sydenham ridge, the stream flows through the field where it was seen by the Association, into the grounds of the Convent of the Faithful Virgin, at the boundary of which it enters a pipe and does not reappear above ground, no other portion of the stream being visible except in a few pieces of ornamental water. The main stream now runs in a sewer. A map which the Director had prepared was exhibited. It showed the original course, with numerous tributaries coming from both sides of the ridge and all joining the main stream south of . A move was then made to Beulah Hill where, by the kind permission of Mr. Homsey Walker, the party were able to see the spring and well-house of the old Beulah Spa, which in the early part of the nineteenth century was a well-known rendezvous for fashionable London who came out to take the waters. The spring is said to have been used by inhabitants of the locality for many years, but it was not until 1831 that it was exploited as a Spa with all the usual attachments of a military band, camera­ obscura, open air concerts, and so forth. It was closed in about 1854. The well, now in private grounds, is still open, and several members tasted the water, which has a slightly chalybeate flavour, and is highly charged with sulphate of magnesia." The party then proceeded to the Grange Wood Museum, where a demonstration was given by Mr. E. A. Martin, the Honorary Curator. The park and museum belong to the Croydon Corporation, and stand upon the final southerly-pointing spur of the London Clay hills, as they here gradually decline into the levels of the Croydon plain. At a time subsequent to the deposition of th e Upper Norwood gravels, Grange Hill must have stood out above the waters in which the Croydon gravel was being deposited, and by means of which the denudation and lowering of the chalk hills to the south were being accomplished. Such waters are now represented by the Wandle, the underground springs of Surrey St., Croydon, the intermittent Bourne from Caterham Valley and Marden Park, and that from Merstham. At Thornton Heath Station cutting, mammoth remains were exhumed from the gravel. Some of these, and others from the Mitcham gravels, are in the museum. Below the gravels at Thornton Heath, the pale grey sands of the Oldhaven series were exhibited to a thickness of about 16 ft. where the railway was widened. A hundred yards to the west, the oyster beds of the series werecut into in Boswell Road during sewering operations a few years ago. In the gravels the silicified fossil urchins Echinocorys and Micrasters • An analysis of the water taken by Michael Faraday showed 61.35 grains MgSo,. · 174 DR. A. B. RENDLE, are very common. The London Clay of Grange Wood throws out at various layers springs, some of which feed a small lake in the lower part of the grounds, and around which a number of butcher's broom plants were noticed to be growing. Mr. Martin called attention to the contents of the museum, particularly to the chalk fossils, to the remains of leaves from the Woolwich Beds, to the Unio and Paludina limestone from Waddon, the stools of cycadaceous plants from Portland, and the pre-Roman remains from Wallington. Over 2,000 Roman coins which were dug up in Croydon (Wandle Road) are exhibited in the museum, as well as a smaller find from South Croydon. Attention was also drawn to the Anglo-Saxon spear-heads, bronze buckets, shield bosses and Roman bowls, dug up in Croydon, and to the coral, shell and mineral collections. The members then adjourned to the refreshment room of the museum for tea, after which a vote of thanks to the Directors was proposed by Mr. Whitaker.

REPORT OF A VISIT TO THE BRITISH MUSEUM (NATURAL HISTORY), BOTANICAL DEPARTMENT.

SATURDAY, FEBRUARY 24TH, 1912.

By DR. A. B. RENDLE, F.R.S., F.L.S., Keeper of the Department.

THE members, .14 in number, assembled 111 the Central Hall, where they were received by Dr. Rendle, and a visit was first paid to the bays devoted to Botany in the Hall. In the first of these an attempt has been made to illustrate the general characters of the seed-bearing plants and the main sub-divisions of the group. At the beginning of the series was an exhibit, specially interesting to geologists, of the Pteridosperrns, an extinct group of Carboniferous times, combining the characters of the ferns on the one hand and of the Cycads on the other. A fern­ like stem and leaf were associated with seed-like structures recalling those borne by present-day Cycads. These Pterido­ sperms are therefore of great interest in indicating how the gulf was bridged between the ancient ferns and the modern flower­ and seed-bearing plants. The distinguishing feature of the latter, which is the dominant group at the present day, and which appeared, so far as geology tells us. suddenly in Cretaceous times, is the presence of a seed containing an embryo which resumes growth (i.e. germinates) after a period of rest.