86 



bulletin: museum of compakative zoology. 



face rock still remains in place. A large body of water flows through 

 uuderneatli this bridge with every ehbing and flowing tide. 



6- 



OCtAN-ilDC 



Fig. 53. Sections across the Rio Formoso sandstone reef. 



Along the landward side the bottom of the channel next to the reef 

 is covered here and there by huge blocks of stone like the upper part 

 of the reef. There are tide-pools over the surface, especially near the 

 landward end. At the outer end the reef breaks off abruptly, and there 



