The velocity fields associated with edge waves on a sloping beach are examined as possible causes of sedimentary features which have a regular, rhythmic pattern in the longshore direction. It is shown that standing edge waves provide a satisfactory explanation for the formation of crescentic bars in regions of small tidal range, the bars having a longshore wavelength of one-half that of the edge waves. In the absence of large, incoming surface waves, the edge waves may also form cuspate features on the beach face, with the points of the cusps directly opposite to the horns of the crescentic bars. This situation is commonly observed in nature (Hom-ma and Sonu, 1963). The results suggest that standing edge waves with periods of 30–60 secs and significant amplitudes must occur extensively on real beaches.