Early in the summer of 1930 there was exposed in the Parkgate Seam, No. 3 Pit of the Manvers Main colliery, Wath-upon- Dearne, near Rotherham, Yorkshire, a large cavity lined with exceedingly beautiful crystals of baryte ; this being the first occurrence of the kind recorded in the south Yorkshire coalfield. The cavity was quickly more or less completely wrecked by the miners, when fortunately my friend, Mr. C. P. Finn, the Company's chemist, had his attention drawn to the matter, and as a result some brief notes on the occurrence, accompanied by a photograph of a specimen, were published by him. Thanks to the efforts of Mr. Finn, and as the result of visits to the colliery, I was able to obtain some very fine and interesting specimens of the mineral.