Some time previous to 1894 the late Sir Henry A. Miers, then an assistant in the Mineral Department of the British Museum, collected together all the books in the departmental library which gave a systematic account of the minerals of particular regions. Since then the set has been considerably added to, and it now forms a very valuable, probably unique, series. Its primary use was for the more precise labelling of the localities of specimens in the collection; and as it grew it became more and more useful for answering inquiries on the minerals of particular districts. In 1900 I started a note-book for collecting further references from the literature. This was added to by the late Mr. George Savigar, clerk in charge of the departmental library; and later Miss J. M. Sweet compiled a card-index of all the entries. The department also has card-indexes of the localities of mineral and rock specimens in the collection.