170 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



c. The coast lakes formed by the closing of the mouths of estuaries 



such as Lagoa Mauguaba, Lagoa do Norte, Jiquia, Sinimbu, etc. 



d. Embayments altogetiier filled up. 



e. The islands along the coast are nearly all close in-shore and have 



the appearance of having been formed by depression of the land. 



f. The buried rock channels at Parahyba, now tilled with mangrove 



swamps and mud, show a depression of at least twelve metres 

 since those channels were cut. 



g. Wind-bedded sand below tide-level on Fernando de Noronha. 



10. The evidences of elevation consist of: — 



a. Elevated sea beaches especially well shown about the Bay of 

 Bahia, and along the coast of the State of Bahia. 



h. Marine terraces about Ilheos in the State of Bahia. These are 

 about eight metres above tide level. 



c. Horizontal lines of disintegration about one metre above high 



tide in granites and gneisses at and about Victoria, State of 

 Espirito Santo. 



d. Burrows of sea-urchins so far above low tide that sea-urchins can 



not now live in them. These are well shown at Pedras Pretas 

 on the poast of Pernambuco. 



11. Of the two movements the depression has been much the greater 

 and was the earlier. 



12. The great depression probably took place in early Pliocene times. 

 (See the chapter on Geology, pages 8 to 33.) 



13. Following the Pliocene depression of the coast, the headlands were 

 strongly eroded, the mouths of bays and estuaries were closed, and the 

 coast line straightened. 



14. The sandstone reefs of the coast were formed and hardened sub- 

 sequent to the depression. 



15. The coral' reefs of the coast have helped build out the shores, and 

 they have likewise protected the land from the destructive action of the 

 waves. 



16. The stone reefs have also protected the laud, and have helped to 

 prevent the encroachment of the sea. 



17. The mangrove swamps have been important agents in building up 

 the newly formed land about estuaries and embayments. 



18. The sands of the coast are not of foreign origin, as has been sur- 

 mised, but are derived from the adjoining headlands, or they have been 

 brought down from the laud by streams. 



