32 THE ESSEX NATURALIST. a short formal meeting of the Club was held, with Miss E. Willmott, F.L.S., V.M.H, member of Council, in the chair (our President having had to leave the party somewhat earlier), when Mr. John H. B. Jenkins, of Glenmore, Tavistock Road, Snaresbrook, was elected a Member, and three nominations for membership were announced by the Acting Hon. Secretary. While waiting for the return train, many of the visitors entered Epping Church, and inspected the elaborate gilt organ-front and the beautiful modern rood-screen and other fittings of this excellent example of modern Gothic architecture. FIELD MEETING AT NORTHWOOD AND RUISLIP. (488th MEETING.) SATURDAY, 8th JUNE 1918. A Field Meeting was arranged in this charming district of Middlesex on this date to enable Members to study the local botany and geology under the leadership of. Mr. Robert Paulson, F.L.S., and Mr. William Whitaker, B.A., F.R.S., F.G.S. respectively. The party, to the number of nearly 30, met at the Pinner and Hatch End station of the Bakerloo extension to Watford at 11.15 o'clock, and made its way across fields radiant with buttercups to Pinner Hill, crossing en route the old British shallow earthwork known as Grimm's Dyke, which marks, in all probability, a pre-Roman tribal boundary, "herborizing" and entomologizing being indulged in by the way. On Pinner Hill, utilising an extensive view southwards over the lower country, Mr. Whitaker gave a short account of the geological features of the neighbourhood, pointing out that, on its passage from the station, the party had crossed an inlier of Reading Beds in a mass of London Clay. Pinner Hill is itself of London Clay, capped by high-level "Plateau Gravel," derived probably from once-overlying pebbly Bagshot Beds, which have long since been entirely denuded away, though beds of similar age still cap Harrow Hill to the south. Mr. Paulson then took up the theme by calling attention to the effect on the tree-flora of the different geological formations. He pointed out that, in woods on the lower London Clay grounds, Quercus pedunculata is the dominant form of Oak, with Hazel association, whereas, on the hill slopes and higher grounds, Quercus sessiliflora becomes the characteristic form, and is associated with Hornbeam, Beech, and Birch. Skirting the growing town cf North wood, the geologists of the party examined a small section in the Reading Beds on the golf-links, just to the south of the town, which showed a line pale-yellow quartz sand without pebbles. Meanwhile, a number of interesting plants was noted by the botanists on the adjoining ground, including again Maenchia erecta, which had been noted at Epping on the last excursion. The most important botanical observation of the day was made at Ruislip Reservoir. The level of the water was low, the reservoir having been partly drained recently, and the margin exhibited a distinct, broad, orange-coloured zone, following the contour of the water along the entire length of the reservoir, for nearly 1/2 mile, and strikingly evident from a