My attention was first called to this District by reading the admirable paper by Mr. J. G. Goodchild on the distribution of the boulders of Shap Granite over the moors in the neighbourhood of the Vale of Eden 1 . In this paper, Mr. Goodchild describes the track taken by the ice which carried the boulders of Shap Granite across the Valley of the Eden, and traces these boulders past Brough-under- Stainmoor to the summit of the Pennine Escarpment, at the head of Lunedale, Balderdale, and Deepdale. Here Mr. Goodchild leaves us, but the rocks have been traced by Prof. Lebour and other observers, down the lower part of Teesdale and out into the North Sea, and also down the Central Valley of Yorkshire as far as the city of York. In the present communication it is my intention to deal with the distribution of the ice in Upper Teesdale, We~irdale, and the Valley of the Tyne, and their tributary valleys, and to discuss certain features produced during the retreat of the ice. Teesdale. (1) Topography and Structure. In order that the details which follow may be better understood, I purpose first to describe briefly the form and the solid geology of the district. The Tees rises on the eastern side of Cross :Fell, and receives several tributaries from the surrounding hills. The upper part of the valley has a low gradient, especially in the region immediately above the waterfall of Cauldron Snout. The upper end is enclosed by a semicircle of