AMERICAN DREDGINGS IN THE CARIBBEAN SEA. 
357 
great depths. We rarely got from deep water, say between 
1,500 and 2,400 fathoms, the rich hauls so invariably made in 
the Gulf from depths of between 1,200 and 2,000 fathoms. 
But we found, what was much more important for our success, 
that the range of the greater number of deep-sea species ex- 
tended within very easy dredging limits, and we soon discovered 
that by dredging mainly between 300 and 1,000 fathoms we 
not only obtained nearly all the species extending to the 2,000- 
fathom line, but obtained them in considerable numbers. This 
enabled us, of course, to collect a large amount of material, 
and the collections of this year’s cruise, combined with those 
of the previous year, added to the older collections made by 
Count Pourtales on the Bibb and to those of the Ilassler , 
make our deep-sea collections but little inferior to those of the 
Challenger. 
I was greatly struck with the large number of our species, 
which, if not identical, are at least closely allied to those brought 
home by the Challenger ; and I was specially disappointed at 
the absence of types not already collected by the great English 
expedition. I think it can be fairly stated that the great out- 
lines of the deep-sea fauna are now known, and that, although 
many interesting forms will undoubtedly be dredged in the 
shallower waters, between 100 and 300 fathoms, we can hardly 
expect to add materially to the types discovered by the dredg- 
ing expeditions of the last ten years. As has been well said by 
Mr. Moseley, of the Challenger , it becomes somewhat mono- 
tonous to find constantly the same associations of invertebrates 
in the deeper hauls, and it is only in shallower waters that it is 
possible to keep up one’s enthusiasm after a few months’ work. 
I should be inclined, from the experience of the past two years, 
to carry the range of the deep-sea fauna as high as 300 or 350 
fathoms, and to call the littoral fauna the species extending 
mainly to the 100 or 150-fathom line ; from the 100 to the 300 
or 400-fathom line extend the species which are neither littoral 
nor yet have the wide geographical range belonging to species 
found beyond that depth. But this upper limit of the deep- 
sea fauna must, of course, depend upon the temperature, and 
undoubtedly varies greatly from local or partly local causes. 
While dredging to the leeward of the Caribbean Islands we 
could not fail to notice the large accumulations of vegetable 
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 1,000 fathoms, ten or fifteen miles from 
land, masses of leaves, pieces of bamboo, of sugarcane, dead lanu 
shells, and other land debris , which are undoubtedly all blown 
out to sea by the prevailing trade-winds. We frequently found 
floating on the surface masses of vegetation, more or less water- 
