The relations of the various rocks of the district lying to the North and South of Nuneaton have already been discussed by Prof. Lapworth from the data afforded by investigation in the field. He put into my hands many specimens of the different rocks for the purpose of microscopical examination. I have also received specimens from Mr. W. J. Harrison, and have collected some myself. Mr. J. J. H. Teall has also placed at my disposal a number of slides which he has had prepared from material of his own collecting.