208 bulletin: museum of comparative zoology. 



along the whole extent of the Brazilian coast, and supposed to be con- 

 tinued inland, where the coast projects beyond the line of the reef." 

 The woodcut of the reef on p. 98 is quite worthless. Elsewhere he 

 says (p. 96) that the reef "extends along the whole coast of Brazil 

 from Cape St. Roque to the Abrolhos near Rio de Janeiro, and is of the 

 same hard coral nature." 



Hartt, Ch. Fred. Geology and physical geography of Brazil, Boston, 

 1870. 



Professor Hartt notes (p. G2) the occurrence of a bit of consolidated 

 beach of " quartz sand cemented by carbonate of lime," just south of 

 Guarapary, Province of Espirito Santo. At Barra Secca, about 30 miles 

 north of the mouth of Rio Doce, he found similar consolidated sands un- 

 covered at low tide (p. 107). Again at As Pedras (Espirito Santo), he 

 found the same kind of sandstone on the sea beach (p. 114). "The 

 arrangement of the materials in this sandstone is precisely like that of 

 the beach, and this formation is only the lower part of a beach ridge 

 which has been cemented by the lime of shells, etc." The rock is very 

 hard ; it is in places broken into blocks which lie tilted about. He 

 suggests (p. 115) the probability of the waters of lakes behind the beach 

 percolating through the sands, and that this might have been an agency 

 in its solidification. 



He speaks of the stone reefs of Brazil in general (p. 185-187), shows 

 how coral and stone reefs have been confused on the Brazilian coast, and 

 how many erroneous statements have passed current regarding them. 

 The Porto Seguro reef is described, and a cross-section given (p. 228-229) ; 

 this reef is said to be remarkably straight, and its height and width even, 

 while it overhangs on the land side. The solidification is said to have 

 extended " many feet below low-water level ; " in places it is coated on 

 the outside by corals ; the lamination slopes seaward ; the rock is sand- 

 stone with calcareous cement. The stone reef at Santa Cruz is described 

 (p. 233), and a sketch map given showing its location. He speaks 

 (p. 342-344) of the consolidated beach sands e?ot of the lighthouse at 

 Bahia ; these sandstones dip seaward, and occur from Bom Fim to Rio 

 Vermelho. They contain fresh shells. The hardening is explained as 

 produced by the solution of carbonate of lime by rain and sea-water from 

 shells in the sands, and redeposition at a lower level. Copious rains, he 

 thinks, aid this work, also waters from marsh lands ; later the loose 

 material is removed by storms or freshets. The Rio Vermelho reef is 

 described and is said to be somewhat elevated. The same section is 



