Barrows, dunes, moat-hills, cairns, and earth or stone mounds of various kinds, abound in many parts of the Old as well as of the New World, and are nowhere more abundant than in some districts of the British Isles. But although corresponding primitive structures are met with from the Gulf of the St. Lawrence to the Isthmus of Panama, and beyond it, far into the southern continent: nevertheless the works of the Mound-Builders have a character of their own altogether peculiar; and though numbered by thousands, they are limited to well-defined areas, leaving a large portion of the continent, including the whole of the Atlantic sea-board, without any traces of their presence. The Mound-Builders were not a maritime people. Their whole traffic was confined to the great rivers, along the banks of which their ancient traces abound, and to communication by long-obliterated overland routes of travel. Notwithstanding the careful observations which have been put on record relative to the mounds and earthworks of “The West,” much yet remains to be disclosed; for, happily, the excavation of such earth-pyramids is a work greatly too laborious and costly to tempt those who are influenced by mere idle curiosity; while their contents, however valuable to the archæologist, offer no such stimulus to cupidity as, in Mexico and Peru, has led to the destruction of thousands of the memorials of extinct arts and customs. As a general rule, the earth and stone works appear to have been alike constructed of materials derived from the immediate neighbourhood; so that such differences do not, in the majority of instances, supply any indication of diversity in the enclosed deposits. A special character, however, appears to pertain to one class, designated “Hill Mounds,” from the sites they occupy. Of these Mr. Squier remarks: “The most elevated and commanding positions are frequently crowned with them, suggesting at once the purposes to which some of the mounds or cairns of the ancient Celts were applied: that of signal or alarm posts. It is not unusual to find detached mounds among the hills back from the valleys, and in secluded places, with no other monuments near. The hunter often encounters them in the depths of the forests when least expected: perhaps overlooking some waterfall, or placed in some narrow valley where the foot of man seldom enters.” Similar structures crown many western heights; but some at least are of Indian origin; and our knowledge of the characteristics and contents of those of an earlier race must be greatly extended, before we can assign the true and probably varied objects aimed at in their erection.