93 
Museum Bulletin No. 25. 
Plate XIX. 
A. Plaster cast of wave marks left by retiring waves, showing fine lines of 
sand left by four successive waves, shore of lake Erie. (Page 24.) 
B. Plaster cast of imbricated wave sculpture formed at the margin of the 
beach by waves crossing a miniature spit, beach of lake Erie at 
Port Colborne, Ont. (Page 34.) 
