Proceedings of the 0/iio State Academy of Science 233 



from its tied end, the effectiveness of this deflecting movement 

 is tempered, and we see in consequence, that the spit continues 

 its development in a straight Hne, leaving the hooked portion as 

 an irregularity on the back slope of the spit ; when the bay has 

 been completely shut off, this constructed form is called a bar. 

 It not infrequently happens that spits are developed outward 

 from either side of a bay, sometimes uniting, and sometimes 

 passing each other, thus isolating the bay. 



In the construction of spits from the windward angle of 

 the bay, sometimes intervening areas are isolated and form la- 

 goons. These lagoons may be developed in series, as when the 

 spit terminates in a hook and later continues to grow forward ; 

 more often, however, the lagoons have long axes parallel with the 

 trend of the bars. 



Through the interference of shore currents, such interfer- 

 ences often arising from deflected movements of water, the loose 

 materials instead of being carried continuously parallel with the 

 shore, are so deposited as to form a cape which gradually grows 

 out into the water. This constructional form is termed a cusp. 



When the shores slopes gradually into deeper water, the 

 higher waves break some distance from the shore ; the work then 

 done is similar to that accomplished by strong waves breaking 

 at the water-margin, that is, material is piled up ; this piling up 

 of detritus in deeper water develops a barrier which is, in real- 

 ity, a submerged beach ridge ; barriers therefore, are parallel to 

 the shore. ]\luch of the material which enters into the construc- 

 tion of barriers has been carried back from the shore by the un- 

 dertow. In time the barrier grows higher, and accordingly in- 

 terferes with the velocity of along-shore currents, causing the 

 water to drop some of the load it may be carrying. From this 

 time on, the barrier grows through these two methods ; it may 

 ultimately rise to the surface of the water and eventually form 

 the shore line proper ; when this happens, the space between the 

 beach ridge or cliff' and the barrier becomes a lagoon. 



We sometimes And a cusp fringed by a barrier ; the pro- 

 cess of its development is identical with the method above (lis- 



