, 24 original; 25 counterpart. This is an illustration of the win- 

 npws or wave ridges of sand pushed together on the beach by suc- 

 cessive overriding and retreating waves or wavelets. 24, the orig- 

 inal, presents them as shallow, narrow, oblique grooves; 25, the true 

 aspect of the surface, is placed so as to bring out the delicate relief 



as effectively as possible. 



[230] 



