The Caribs, who inhabit the shores of the Caribbean Sea, are a nautical people, who conquered the Antilles, as is attested by their war implements being found there, and entered North America by the southeast, and spread north to Canada, giving rise to the red Indian, whose dolichocephalic skulls and roving habits agree precisely with the Caribs of Venezuela. The brachycephalic type is supposed to have entered America by Behring’s Strait, giving rise to the Aleutians and Esquimaux, and passing through Washington Territory and California has characterized the Hualpa Indians of the latter, and the semi-civilized cliff-dwellers of Colorado and Pueblo Indians of New Mexico. The high degree of civilization which Cortez found in Mexico, the unnumbered temples of the Montezumas, the splendor of Toltec civilization, the paved roads of Peru, and the gilded palaces of the sun-worshipers of Lake Titicaca, all show that the brachycephalic civilization of the Pacific Slope was as distinct from the culture of the hunting tribes of the Atlantic, as though separated by an ocean. In the Chicago Academy of Science are a number of Mound-builders’ skulls, taken from mounds in Ohio, Indiana, Kentucky and Illinois. There are no other skulls of any other race in this country like them—with scarcely any forehead whatever, but with a sudden slope from the superciliary ridges backward. These skulls are neither dolichocephalic nor brachycephalic; therefore we can neither look to the ancestry of the Red Men, nor to the Asiatic type, for the progenitors of the Mound-builders, who may justly be considered the autochthones of America. Before attempting to account for the presence of the Mound-builders in the Mississippi Valley, we will describe a few of their mounds, the only history they have left us.