83 
Museum Bulletin No. 25 . 
Plate XIV. 
A. Ripple-mark of irregular pattern resulting from junction of incoming 
waves and ebb current; view on spit looking toward E, Figure 5, 
Annisquam, Mass. (Page 32.) Photograph by G. K. Gilbert. 
B. Imbricated ripple-mark resulting from converging waves and tidal cur- 
rents looking in direction opposite to that in A, Annisquam, Mass. 
(Page 32.) Photograph by G. K. Gilbert.) 
