of the Bahama Islands. 323 



Dana as already quoted, refers to parallel bands of greater 

 and less subsidence in the Pacitic Ocean, and to analogous 

 conditions in the Atlantic; — the subsidence was probably, 

 he says, "much greater between Florida and Cuba than in 

 the Peninsula of Florida itself; and greater along the Carib- 

 bean sea parallel with Cuba, as well as along the Bahama 

 reefs, than in Cuba." Recent soundings show in these re- 

 spects the following facts : 



The greatest depth in the Gulf of Florida, between Key 

 West and Havana is within 5 miles of the latter, 800 fathoms 

 (4,800 feet), and I have already stated that there is a depth 

 in the Nicholas Channel, between Salt Key Bank and Cuba 

 of 534 fathoms (3,204 feet). 



Between Cuba and the east end of Jamaica the depth is 

 1,244 fathoms (7,464 feet). Eastward of Jamaica, along 

 the southern side of Haiti, in about the latitude of Beata 

 Island, great depths have been ascertained, — one sounding 

 west of that Island gave 2,136 fathoms (12,816 feet), and 

 one to the eastward of it 1,840 fathoms (11,040 feet). The 

 greater subsidence still further to the east, between the Vir- 

 gin Bank and St. Croix, may be inferred from the enormous 

 depth there found of no less than 2,580 fathoms (15,480 

 feet) . 



A line of soundings from the south side of Jamaica and 

 east of the Pedro Bank, across the Caribbean Sea to Aspin- 

 wall (a distance of about 550 miles), shows the instructive 

 fact that, with no very considerable exception, the sea bot- 

 tom slopes gradually from Jamaica towards the coast of the 

 Isthmus of Panama. About 60 miles from Manzanilla Point 

 (N.E. of Aspinwall), the depth is 1,215 fathoms (7,290 feet). 

 The bottom then rises comparatively rapidly, — the depth at 

 about 40 miles from Aspinwall being 677 fathoms (4,062 

 feet), and at about 20 miles, 227 fathoms (1,362 feet). 



of studying the land shells of the Bahamas, to the late Mr. Wm. Cooper, Dr. Bryant, 

 and Mr. Robert Swift : al^o to Mr. W. W. Miller, Mr. Daniel Sargent, of Inagua, and 

 Dr. Weinland, hut especially to Mr. Rawson W. Rawson formerly Governor of the Ba"- 

 hamas, and now of Barbadoes and the Windward Inlands. 



