BRANNER: THE STONE REEFS OF BRAZIL. ' 7 



headed by our able fellow-countryman, 0. A. Derby, are undertaking 

 topographic maps. 



Many kind friends have placed me under obligations by their cordial 

 assistance in connection with this work. Mr. Whitaker, formerly Presi- 

 dent of the Geological Society of London, has helped me with valuable 

 references. At Washington, Mr. Hay, Secretary of State, kindly fur- 

 nished me with letters to the diplomatic and consular representatives of 

 the United States in Brazil, and procured for me letters from the 

 Brazilian minister at Washington to the governors of the Brazilian 

 states to be visited. 



In Brazil, tlie governors and the American representatives were 

 extremely obliging ; without their co-operatiou it would have been im- 

 possible to carry on my work. Mr. Guy Swift of Pernambuco, the 

 former head of the firm of Henry Forster and Company at that place, 

 has, by his high standing as a business man and his acquaintance with 

 the country and the people, been of the greatest possible service. Mr. 

 Kenneth C. Macray of Maceio, by his kindness and hospitality, made it 

 possible for the expedition to accomplish at that place much that without 

 such aid could not have been done. 



As stated above, the last expedition in connection with this work was 

 made in 1899, and was provided for by Dr. Alexander Agassiz. I was 

 accompanied by several volunteer assistants : Ray Collins, B. H. Collins, 

 Harold Havens, and C. E. Gilman, at that time students of geology in 

 Stanford University. Mr. Gilman made most of the maps of special 

 areas. My principal assistant was Dr. Arthur W. Greeley, now of 

 Washington University, at St. Louis, who had entire charge of the bio- 

 logic work. Dr. Greeley prepared the paper on the corals at the end of 

 this repoi't. The materials collected by him were sent to specialists, and 

 the following papers have already been published upon them by the 

 Washington Academy of Sciences : "Crustacea" by Mary J. Rathbun ; 

 " Isopod Crustacea," by Harriet Richardson ; " Mollusca," by W. H. 

 Dall; "Fishes," by C. H. Gilbert. 



The original maps accompanying this paper — those by jSIessrs. Gil- 

 man and Havens — wei'e made with a six-inch compass needle for 

 taking bearings, while distances were either paced or determined by 

 triangulation. The long reefs were all paced ; the isolated rocks were 

 located by triangles. 



