Vlll INTRODUCTION. 



cal horizons and periods loom up before us, and the problems 

 concernin<r the formation of continents and oceanic basins now 

 present themselves from a very different standpoint. Our ideas 

 regarding the formation of many marine deposits have been 

 greatly modified, and we are now able to look back into the 

 past history of the world with more confidence than heretofore. 



The plans of the equipment of our expeditions were naturally 

 discussed with the Superintendent of the Coast Survey, with the 

 commanding officers, Lieut.-Commander Sigsbee and Commander 

 Bartlett, and during the cruise the criticisms and suggestions of 

 the commanders, of Lieutenants Ackley, Sharrer, Mentz, and of 

 the other officers of the sliip, Messrs. Jacoby, Reynolds, and Pe- 

 ters, constantly modified our methods of work, and gradually 

 changed our apparatus to such an extent that it would have 

 been difficult to recognize the original dredging implements as 

 first devised. The exact share of each in these changes it is 

 impossible to state.^ 



During the season of 1877-78 the dredging operations carried 

 on from December to March by the " Blake," in command of 

 Lieut.-Commander C. D. Sigsbee, U. S. N., extended from Key 

 West to Havana, from Havana westward along the north coast 

 of Cuba, from Key West to the Tortugas, thence to the north- 

 ern extremity of the Yucatan Bank, to Alacran Reef, back to 

 Cape Catoche, and across to Cape San Antonio, returning to Key 

 West, and from Key West to the Tortugas, and northward to 

 the mouth of the Mississippi River. See track of " Blake," 

 Fig. A. After I left the " Blake " that year, Sigsbee occupied 

 a number of stations off Havana in search of Pentacrinus, of 

 which we had obtained a quantity of fragments in the early part 

 of the cruise. He succeeded in discovering their haunts, and 

 was the first to dredge a number of specimens from a locality not 

 far from the Morro Light, which has become known as Sigbee's 

 Pentacrinus ground. 



Notwithstanding the delays incidental to bad weather and to 

 the unfortunate grounding of the " Blake " at Bahia Honda 

 while in charge of a Spanish pilot, so that nearly three weeks 



1 A detailed description of the " Blake " moir on deep-sea sounding and dredging, 

 ecpiipment is given by Sigsbee in his me- published by the U. S. Coast Survey. 



