56 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



is composed largely of the sand of calcareous seaweeds of the same species 

 as those now living on the coral reef outside the barra. The exposure of 

 recent sandstone here is only about two hundred metres in lengthy and 

 the locality is a little to the north of opposite the most northern exposure 

 of consolidated beach on the ocean side of this neck of land, which is 

 here seven hundi-ed and seventy metres in width. The peninsula is all 

 low, flat and sandy or swampy, and there are no hills on the south side 

 of the Rio Parahyba do Xorte until near the city of Parahyba about 

 seventeen kilometres up the river. 



Something will be said of the physical features of the region about 

 the mouth of the Rio Parahyba do Xorte in the part of this paper treat- 

 ing of the elevation and depression of the coast. 



The Pedra de Gale or Goyanna stone reef. — The Goyanna stone reef 

 or reefs lie off the mouth of Rio Goyanna, State of Pernambuco, one part 

 of it being north and the other south of the Barra de Goyanna. Only 

 the northern part of this reef was examined. 



This northei'n reef is known to the sailors of the coast and to the peo- 

 ple of the region as the Pedra de Gale or Recife de Gale} 



The country to the west is hilly (Tertiary) both north and south of 

 Rio Goyanna, and the river enters the sea through a flat region. The 

 outstanding point between the hills is a low sandy flat planted with 

 coco palms, but further west mangrove swamps stretch across the val- 

 ley. The water landward of the reef is mostly shallow. The dredge 

 brought up here only sand with a few shell fragments. 



The reef is only a short one, is quite isolated, stands well out from the 

 shore, and ends abruptly without any sign of a submerged continuation 

 so common with the stone reefs. It is only a few hundred metres long, 

 and varies in width from 15 to 25 metres. The surface is flat in the 

 main, but has a gentle seaward slope. The rock is very hard and can be 

 readily broken only on the projecting points left by etching. The sur- 

 face is pitted unevenly, but the stone is nowhere bare. In places the 

 rock is cracked, and great blocks, ten or fifteen metres across, have 



1 These reefs are not properly located on the hydrograpliic chiu-t of this coast. 

 The northern one is there represented as lying nine miles north of the bar: by 

 measurement it is about a third of a mile. The southern reef is represented as 

 being seven miles. long. That piece I did not measure, but as we saw it from our 

 Inrcarn with the chart before us it did not seem to be nearly so long, even with all 

 the outlying fragments included. The direction of the axis of the reef with refer- 

 ence to the land is also incorrect: the entire northern reef is in line with the low 

 flat land one quarter of a mile west of Ponta de Pedras. Its magnetic bearing ia 

 north 27° east. (June 17, 1899.) 



