“Selecting any pebbly beach where the stones are prevailingly of small enough size to be readily tossed about by the waves, the observer will note that at almost all times, but especially after a heavy storm, the slope from the high-water mark downward is scalloped in a curious manner. From the level beyond the waves, ridges tapering outwardly extend down the incline, it may be, for a distance of ten to fifteen feet or more, and a height of from a few inches to two or three feet. Between these ridges, which taper toward their lower and outer parts, there are small, wedge-shaped embayments, which a t the outer edge of the ridges may be from two or three feet to fifteen or twenty feet wide, tapering thence, like the section of a rather pointed cone which is obtuse at the apex, to the edge of high water. These scallops . . .