Northeast Coast of Brazil. 



373 



The first observed occurrence of the typical reef rock north 

 of Jacuma is near the mouth of Rio do Fogo, 2i miles away in 

 a direct line. About one-half mile north of the mouth of this 

 small stream a reef of the usual material appears off-shore and 

 trends N. 20° W. (mag.) while the beach trends N. 6° W. 

 Hence after a short distance the reef attains the beach, at a 



Fig. 8. Positions of calcareous sandstone reefs relative to the present 

 beach: a, near Pitangy ; b, near Jacuma 1 ; c, near Rio do Fogo ; d, north- 

 west of Ponta Eeducto. 



place where the beach turns a little more to the west (fig. 3c). 

 At this place the reef also turns, but at an angle instead of in 

 the nearly universal gentle curve, and bearing N. 16° W., ex- 

 tends for about six-tenths of a mile in a straight line nearly 

 parallel with the beach, finally disappearing in the surf. A 

 reef which is exposed for a width of 200 or 300 yards at low 

 tide and extends for some distance southward from the mouth 

 of Rio do Fogo, appears to consist of quartz grains cemented 



