The extraordinary _dispersion of erratic blocks_ over the surface of the ground remains to be noticed, and constitutes one of the most remarkable phenomena in local glacial geology. I distinguish the boulders resting on the surface of the ground from those embedded in the clay beds, although it is of course possible and probable that the clay has been largely denuded, and the boulders have thus been left exposed. Many of these erratic blocks may therefore belong to the Lower Boulder Clay; while others may have fallen from the icebergs which during the proved subsidence of the land must have floated over the “Midland” sea, and have been deposited in the Upper boulder clay, while it was in process of accumulation. How far the dispersion of erratics over the Midlands may be referred to the ice sheet of some geologists, or to the icebergs of the Archipelago period in the history of Great Britain, must, at present, be regarded as an open question. The Midland erratics have undoubtedly travelled from three distinct regions, viz., (1) from Wales, (2) the western part of the Lake district, and (3) Kirkcudbrightshire. Boulders from the more easterly part of the Lake district, such as the Snap granite boulders, so abundantly spread over Yorkshire, have not been found in this neighbourhood. The peculiar distribution of the Midland erratics is noteworthy. Commencing at Bushbury Hill (a little to the north of Wolverhampton, on the table land facing towards the N.W.) the Lake rocks and the Scotch rocks--Criffell granites and Eskdale granites--are largely intermingled. Journeying westwards, a stream of boulders from Wales crosses the northern streams. On and around the Clent Hills (1023 feet) south west of Birmingham, Welsh felsites are the only boulders to be found. Birmingham itself being in the rear of the higher part of the table land on which it stands, is in a kind of protected district, so far as the northern stream of boulders is concerned, and the erratics in its immediate vicinity are chiefly Welsh felsites; a few fragments however of granite are occasionally found. POST GLACIAL BEDS.--The most complete section of post glacial beds in this locality was obtained during excavations made at Shustoke, near Birmingham; when a bed of black peat, containing the remains of _Elephas antiquus_, _Cervus elephas_, and _Bos primigenius_, with hazel nuts and fragments of wood, was discovered 7ft. 6in. beneath the surface. The section was as follows:-- Soil 1ft. 0in. Sandy marl 1ft. 8in. Yellow clay (stiff) 3ft. 8in. Blue clay (stiff) 1ft. 2in. Black peat 1ft. 10in. “Ballast” gravel and sand 3ft. 0in. Sandstone and marl. The fossils found in the peat have been placed in the Geological Museum of the Mason College. PETROGRAPHY. Notes on the Igneous and Metamorphic Rocks of the Birmingham District. BY S. ALLPORT, F.G.S.