90 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
detached fragments lying beyond its southern end, and not shown on 
the map herewith, which would give it a total length of something more 
than a kilometre. 
A fact of unusual interest in regard to this bit of reef is that it over- 
lies a dead coral reef. The overlap is plainly visible at many places 
Fic. 57. Section across the stone and coral reefs at Sapucahy. The vertical 
shading on the right represents the coral reef. 
where re-entrant angles have notched the stone reef, or where large frag- 
ments have been left isolated but fast to the coral reef. 
The coral reef visible here at low tide is from one hundred to two 
hundred and seventy metres wide, measured from the outer margin to 
where it is overlapped by the stone reef or by the beach sands. This 
coral reef is almost perfectly flat and level. Not a single living coral 
Ta „ Ocean 
Fic. 58. Sketch map of the southwest end of the stone reef at Paripueira, 
State of Alagoas. 
could be found on its upper surface; the coral most abundant in the 
rock itself is Porites. 
Outside or seaward of this reef is still another coral reef with which 
the inner one is not connected at the water’s surface at least. 
