Vill INTRODUCTION. 
eal horizons and periods loom up before us, and the problems 
concerning the formation of continents and oceanie 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 ship, 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, 
equipment is given by Sigsbee in his me- published by the U. S. Coast Survey. 
