This paper is intended as a sequel to “Reconstruction of the Antillean Continent,”* in which the submarine valleys of the West Indian region are mapped, but its completion has been postponed, while the writer was engaged on other West Indian and Central American investigations, the results of which have appeared from time to time. In these later papers the details of the submarine topography are elaborated, but no additional studies along the Atlantic coast have been completed, though there is a fragmentary notice of some of the valley-like features.* While the key of the subject is among the West Indian islands and off the coast of Florida and Georgia, the features so repeat themselves farther northward, along the great submarine slope, that they are worthy of careful consideration. So also in the north Atlantic, between Greenland and Europe, the region is full of interest. Although the soundings off the . . .