LITERATURE OF THE SUBJECT 



608 



read that the cusps are "component features of a heach ridge, . . . 

 The ridge . . . has at times been seen and photographed with water 

 caught behind and rushing out at breaks in the line, as with the weed 

 line at hjnn." Whether or not the breaking of water through the bar- 

 rier is still thought to originate the cusps is not made clear. The cross- 

 waves noted by Branner were observed by Jefferson, but at no place did 

 he find such waves associated with cusp formation. 



In his paper, "Cuspate Forelands along the Bay of Quinte^^ (1904), 

 Dr. A. W. G. Wilson describes the occurrence of "cusplets" on one of the 

 forelands, and ascribes them to the action of a single series of waves 

 striking the beach at an oblique angle. Although Doctor Wilson does 

 not refer to the previously published accounts, and although the very 



Figure 



-Diagram illustrating the Formation of Cusps 



The cusps of different sizes are formed on a straight beach, D. E. If D C were the beach 

 line, these waves would produce cusps of uniform size. (After Branner.) 



asymmetrical forms described by him differ in some respects from the 

 essentially symmetrical features generally known as beach cusps, there is 

 little reason to doubt that the former are modified phases of the latter. 

 . In 1905 Professor Jefferson published a paper entitled "On the Lake 

 Shore," in which he gives a brief account of beach cusps, and says "they 

 never occur except after waves that have played squarely on shore." Ex- 

 amples which must have formed without the aid of a seaweed barrier are 

 figured, but their origin is not explained. In referring to one particular 

 set, however, Jefferson classes them with the Lynn beach cusps, and says : 

 "Some high wave surmounts the ridge, here of sand, there of seaweed, 

 and its crest water is ponded behind it to escape by any sags that may 

 occur in the line." 



The writer^s attention was directed first to the cusps in the fall of 1908. 

 At the New York meeting of the Association of American Geographers 

 in December, 1906, he presented a paper, "The Origin of Beach Cusps," 



