Coastal charts afford almost the only means by which we can study continental shelves. In such studies we can employ several methods. We can draw profiles, construct contour maps of the shelves and compare them with maps of adjacent lands, plot the zones of sediment and try to determine their significance, and study the shape and character of the shorelines. The writer has used all these methods in his study of shelf phenomena in the charted regions of the world. This study has shown that we can learn little of the history of the shelves without first getting information concerning all the coasts of the world, and that the character of parts of the shelves is nearly everywhere clearly related, to the character of the adjacent coast. One kind of shelf is typical of regions where large rivers empty into the sea; another is typical of glaciated coasts; another . . .