The geologic distribution of coal is described in “The Coal Resources of the World,” the most important and comprehensive compilation on coal reserves ever made, which was undertaken by the Executive Committee of the Twelfth International Geologic Congress, held in Canada in 1913. As the compilation was made with the assistance of geological surveys and mining geologists of the several countries of the world, it is cited in this paper as authoritative on geologic distribution and resources. The geographic distribution of the chief coal fields of the world is shown in Plate II. In _North America_ the most important coals in the Central and Eastern part are of Paleozoic age, but in the Rocky Mountain region vast quantities of coal occur in the Cretaceous (Mesozoic) strata. In the Gulf province and in the Northern Great Plains province of the United States, which extends into Canada, are coals of Triassic (Mesozoic) age that are relatively unimportant at present. In beds of the Eocene period of the Tertiary era are large deposits of brown lignite locally converted by mountain-building forces into bituminous and semi-bituminous coal, and also a little anthracite under difficult mining conditions. Such locally altered beds are found in the State of Washington, in British Columbia, and in Alaska. The limited coal resources of _South America_, in those deposits east of the Andes and in southern and eastern Brazil, are of Paleozoic age. Small areas of Tertiary coals are found in southern Argentina and in Chile. Key to Plate II. World’s Coal Reserves as of 1916--Coal Fields in Solid Black. 1. Countries possessing coal reserves of the first magnitude (4,000,000 million to 1,000,000 million tons): The United States (3,527,000 million), Canada (1,234,000 million), and China (1,500,000 million). 2. Countries possessing coal reserves of the second degree of magnitude (500,000 million to 100,000 million): The British Isles (189,533 million), Germany (before the war) (423,356 million), Siberia (173,879 million), and Australia (165,572 million). 3. Countries possessing coal reserves of the third degree of magnitude (80,000 million to 16,000 million tons): France (before the war) (17,583 million), Alaska (16,293 million), Colombia (27,000 million), Austria-Hungary (before the war) (55,553 million), Russia in Europe (before the war) (60,106 million), India (79,001 million), Indo-China (20,000 million) and South Africa (56,200 million). 4. Countries possessing coal reserves of the fourth degree of magnitude (16,000 million to 6,000 million tons): Spain (8,768 million), Japan (7,970 million), Belgium (11,000 million), Spitzbergen (8,750 million).