BRA.NNER : THE STONE REEFS OF BRAZIL. 45 



readily dug into with the sharp end of a geological hammer. Excellent 

 examples cover much of the beach just north of Bahia Formosa, where 

 the views reproduced in the plates were taken. 



The examples mentioned as having been observed at the south end 

 of the Cunhahu reef are the only ones seen upon a stone reef. 



The Traic.ao stone reef. — The Trai9ao reef lies in front of the Baliia 

 de Traiqao in the State of Parahyba. This and the Mamanguape reef 

 to the south of it really form, or rather they appear once to have 

 formed, one single and continuous reef, and to have been separated by 

 the breaking down of what may now be called the southern end of the 

 Trai9ao reef. 



The topographic features of the country back of the Trai9ao reef are 

 of rather more than usual interest, and what is said here upon this sub- 

 ject, in so far as it bears upon the origin, form, and history of this reef, 

 is equally applicable to the Mamanguape reef. 



To the west is a table-land of Tertiary sediments from twenty to 

 forty metres high, of pretty even elevation and sky-line, but notched 

 here and there by streams. This plateau, where it comes down to form 

 the coast bluffs north of Trai^ao, is shown in Plates 29 b and 30. 



The sky-line at this place is noticeably less even than it is further 

 south along this coast ; the field notes on the locality remark that north 

 of this place outlines of the coast hills have the appearance of sand hav- 

 ing been blown over them. Where Plate 30 was taken the bluffs end 

 abruptly as beach bluffs, and, swinging westward and northward with 

 somewhat gentler slopes, pass along the east side of a long narrow 

 marsh (for several kilometres, I was told), then return southward along 

 the west side of this same marsh or lake and continue nearly due south 

 until they approach near the Rio Mamanguape. Here the river makes 

 a wide gap through these hills, but south of the .stream they come to 

 an end as inland hills at the Mirici red bluffs at the south end of the 

 Mamanguape reef. 



West of the village of Traigao the church of Sao Miguel dos Milagres 

 stands on the top and edge of this Tertiaiy plateau. Between the 

 bluffs of Sao Miguel and the town of Trai^ao the hydrographic chart 

 shows a lake, known here as Lagoa de Sinimbii.^ By courtesy it may pass 

 as a lake, but strictly speaking it is little else thau a fresh-water marsh 

 with a sluggish stream flowing through it. 



The Lagoa de Sinimbii is separated from the ocean by a low bank of 



1 Tlie name given on the chart may have been its name formerly, but it is now 

 called Sinimbii. 



