88 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



three hundred metres long. Beyond this, however, there are several 

 isolated patches lying in the direct axis of this portion and stretching 

 halfway across tlie embayment or curve in the coast line north of 

 Tamandare. This bit of reef, together with the isolated fragments at 

 its southern end, is in a line with the stone reef of Eio Fornioso. Just 

 behind or landward of this small reef, and about a hundred metres from 

 it, there is still another sand reef lying along the beach. This on-shore 

 reef is parallel with the outer one, but in composition it is softer, though 

 of the same kind of material. It has a gentle dip seaward. Its sea- 

 ward face is broken off squarely wherever the open sea strikes it. 



There are also a few remains of hardened sand rock between the Rio 

 Formoso reef and the high lands west of it, but these remains or bits 

 are scattered, and without the linear arrangement that characterizes 

 the stone reefs. One of these localities is at Gamella Point, where soft 

 calcareous sandstone is uncovered by the encroachment of the sea. At 

 the Guadalupe Point, where the sea is also encroaching, a soft calcareous 

 rock is being uncovered at high tide-level, less than a metre below the 

 surface of the sandy soil. 



The map herewith, and most of the observations embodied in the 

 part relating to Rio Pormoso, were made by the writer in 1876. On 

 revisiting the place in 1899 considerable changes were noticed in the 

 beaches. At Gamella Point the sea was found cutting the land so that 

 a large Gamelleira tree, that in 1876 was well up on the beach, and 

 beyond the reach of the sea-water, is now a dead stump a dozen metres 

 to the seaward of the high tide mark. Guadalupe Point is being cut 

 away on the east side and filled in on the west. The holder of the 

 property at this place states that he has lost more than a thousand 

 coco palms by the encroachment of the sea during the last seven years. 

 This point was mapped again July 27, 1899, and the two outlines are 

 shown, with their appropriate dates, on the accompanying map, 



Tlie stone reefs of the Bio Sapucahy, Alagoas. — The Eio Sapucahy is 

 a small river in the State of Alagoas entering the ocean about thirty 

 kilometres (in a straight line) northeast of Maceio, and three kilo- 

 metres northeast of the village of Paripueira. The country west of 

 the mouth of the river is, like most of the northern coast of Alagoas, a 

 plateau of Tertiary sediments cut across by the river, and a strip of 

 low flat land, partly mangrove swamps and partly sand flats, intervening 

 between the base of the hills and the ocean. 



The Sapucahy stone reef lies right across the mouth of that river, 

 and the stream debouches right and left round both ends of it. It is 



