INTRODUCTION. xi 



While at the Tortugas we were allowed by the Secretary of 

 War to occupy such quarters at Fort Jefferson as were not oth- 

 erwise needed, and we selected as a laboratory a large room, 

 with excellent light, on the ground floor of the barracks. On 

 days when the weather was not suitable for surface work out- 

 side in the Gulf Stream, I employed the launch in cruising 

 inside the reef, and thus examined carefully the topography of 

 the different groups of corals characteristic of the Florida reefs. 

 The results of this visit, as well as those made on previous occa- 

 sions, have enabled me to give a somewhat extended account of 

 the Florida reefs in a special chapter of this book. We re- 

 mained at the Tortugas five weeks, and returned to Key West 

 in the revenue steamer " Dix," Captain Scammon, whom the 

 Secretary of the Treasury had authorized to assist us as far as 

 practicable. At Key West we occupied as a work-room the 

 loft of the Navy Depot building, and continued our studies of 

 the pelagic fauna of the Gulf Stream. 



During the second dredging season (1878-79), the " Blake" 

 was in charge of Commander J. R. Bartlett, U. S. N. The cruise 

 extended from Washington to Key West, from Key West to Ha- 

 vana, from Havana to Jamaica through the Old Bahama Chan- 

 nel and Windward Passage, from Jamaica to St. Thomas along 

 the south coast of Hayti and Porto Rico. From St. Thomas 

 the " Blake " visited Santa Cruz, Saba Bank, Montserrat, St. 

 Kitts, Guadeloupe, Dominica, Martinique, St. Lucia, St. Vin- 

 cent, the Grenadines, and Grenada ; she also carried the dredg- 

 ings south as far as the hundred - fathom line off Trinidad, 

 returned to St. Vincent, and finished the dredging operations 

 at Barbados. 



On November 27, 1878, I joined the " Blake " at Washing- 

 ton for a second dredging cruise. We intended to proceed to 

 Nassau, and there devote a few days to dredging and sounding, 

 in order to trace the connection between the fauna of the north- 

 ern extremity of the Bahama Banks and that of the Straits of 

 Florida. On account of rouoh weather this was not deemed 

 prudent, and we were compelled to put into St. Helena Sound ; 

 and, for the same reason, when off Jupiter Inlet, instead of 

 crossing the Gulf Stream to make Nassau, it was thought best 



