In the afternoon went to where the Highgate- St Alban's road crosses the Hampstead Brook, thence the east of the road one collected in Stovells locality for fossils and got 3 or 4 trilobite heads. They may be determinable. This is the Highgate slate. Then went down the brook over the falls to the lower flat level. Most of the distance down is on the dip slope of the Highgate dark blue slates and found them all crumbled. Finally to one surprise found them on a lane by a thicket hidden very massive dolomite. Keith thinks it is the Orilton thrust where the Highgate To the east of the road the slates dip to the S.E. There is therefore an anticline here, and probably the one seen under the Highgate Falls bridge. Then went to Rockbridge to see the fine grey limestone (Keelburn) lenticles. Finally about 1/2 mile north to see the fine Orizontian conglomerate overlying the Mallett dolomite. A. Keith gave one a few Lingulellas collected at locality C on maps.