SUBMARINE DEPOSITS. 291 



While dredging to the leeward of the Caribbean Islands, we 

 could not fail to notice the laro-e accumulations of vesretable 

 matter and of land debris brought up from deep water many 

 miles from the shore. It was not an uncommon thing to find 

 at a depth of over one thousand fathoms, ten or fifteen miles 

 from land, masses of leaves, pieces of bamboo and of sugar- 

 cane, dead land shells, and other land debris, undoubtedly 

 blown out to sea by the prevailing tradewinds. We frequently 

 found floating on the surface masses of vegetation, more or less 

 water-logged, and ready to sink. The contents of some of our 

 trawls would certainly have puzzled a palaeontologist ; between 

 the deep-water forms of Crustacea, annelids, fishes, echinoderms, 

 sponges, etc., and the mango and orange leaves mingled with 

 branches of bamboo, nutmegs, and land shells, both animal and 

 vegetable forms being in great profusion, he would have found 

 it difficult to decide whether he had to deal with a marine or a 

 land fauna. Such a haul from some fossil deposit would natu- 

 rally be explained as representing a shallow estuary surrounded 

 by forests, and yet the depth might have been fifteen hundred 

 fathoms. This large amount of vegetable matter, thus carried 

 out to sea, seems to have a material effect in increasing, in cer- 

 tain localities, the number of marine forms. 



We can thus see the method by which land shells, small sau- 

 rians, and insects of aU sorts, may readily be transported from 

 island to island, and we might possibly trace the actual path 

 taken by the immigrants into the Lesser and Greater Antilles 

 from the northern parts of South America. 



We made three casts off the coast of Cuba, between Nuevitas 

 and Cape Maysi. In Lat. 21° 2' N., Long. 74° 44^ W., off Cayo 

 de Moa, in 1 ,554 fathoms, we found a patch of greensand, made 

 up of large globigerinae, similar to that mentioned by Pour- 

 tales in his " Deep-Sea Corals." We also obtained, in 994 

 fathoms off Nuevitas, large blocks of genuine white chalk, com- 

 posed mainly of globigerinae and pulvinulinae. Large quanti- 

 ties of ooze and white clay, which proved to be only the white 

 chalk in different stages of compression, also came up in the 

 trawl. If the conditions now existing at that depth at all re- 

 semble those of the time of the white chalk, I can readily un- 



