222 CONFERENCE ON PALEOZOIC PALEOGEOGRAPHY 



Albatross show that in certain regions of terrigenous deposits, especially 

 within the tropics, vegetal refuse is abundant on the ocean bottom, even 

 at depths of more than 2,000 fathoms. Thus Agassiz states that 



"While dredging to the leeward of the Caribbean Islands, we could not fail 

 to notice the large accumulation of vegetable matter and of land debris 

 brought up from deep water many miles from the shore. It was not an un- 

 common 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 pre- 

 vailing 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, 

 etcetera, 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 

 naturally be explained as representing a shallow estuary surrounded by for- 

 ests, 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 certain localities, the number of marine forms."* 



The descriptions of the bottom deposits explored by the Challenger^ 

 mention the occurrence of twigs, woods, and seeds at a depth of 800 

 fathoms near Ki Islands, and the presence of twigs and leaves within 20 

 fathoms off the coast of Amboina Island, both localities being west of 

 New Guinea. Palm fruits and fragments of wood and bark were found 

 at a depth of 2,150 fathoms in the group of islands south of Mindanao, 

 and fragments of leaves, stems, and wood, the latter overgrown with 

 Serpula, were dredged from a depth of 1,050 fathoms at a station about 

 50 miles off the west coast of Luzon. 



Agassiz, in his account of the explorations of the Albatross off the west 

 coast of Central America, notes that : 



"A very fine mud was the characteristic bottom we brought, often very 

 sticky, and enough of it usually remained in the trawl, even when coming up 

 from depths of 2,000 fathoms, materially to interfere with the assorting of 

 the specimens contained in our hauls. This mud continued all the way from 

 the Galapagos to Acapulco, and up to the mouth of the Gulf of California, 

 where it became still more of an impediment to dredging, so that little worK 

 was done until we passed the Tres Marias, Even then the trawl was ordi- 

 narily well filled with mud, and with it came up the usual supply of logs, 

 branches, twigs, and decayed vegetable matter. 



2 Bull. Mus. Com. Zool., Harvard Coll., vol. xiv, p. 391. 



3 Deep-sea deposits, pp. 95, 97, 99, 101. 



