THE WEST INDIAN FAUNA. 3 
In discussing the results of the “ Blake" collections, I have 
availed myself most freely of the work done by other expedi- 
tions, as this is indeed essential for the proper understanding of 
the special facts examined. We are only on the threshold 
of our knowledge of the species and their exact distribution 
over the sea bottom ; nevertheless the data of the various deep- 
sea expeditions seem to show that we know enough to form a 
- general idea of the biological conditions under which these spe- 
cies exist, and that, judging from a few better known groups, 
our ideas are not likely to be materially modified by future 
researches. 
This is especially the case with the West Indian fauna, and 
that of the east coast of the United States. We may safely as- 
sume that but little will hereafter be added to our notions 
of the association of the sponges, polyps, corals, echinoderms, 
crustacea, and mollusks, composing the West Indian deep - sea 
fauna, and making it in certain groups by far the richest in the 
world. The number of new forms from the West Indian region 
constitutes such a vast addition to our knowledge of the princi- 
pal classes of invertebrates of that fauna as to revolutionize our 
ideas of geographical as well as of bathymetrieal distribution. 
No other region of the ocean bottom has yielded so abundant 
a harvest, and we have therefore no data elsewhere sufficiently 
complete for comparisons with regard to geographical distribu- 
tion. But for ascertaining the bathymetrical distribution, and 
its bearing on the determination of the probable depth in which 
strata of former ages containing corals were deposited, the ma- 
terial at hand is of great importance. 
I cannot give a better idea of the value of the collections 
brought together by the “Blake,” than by contrasting the sta- 
tistics of some of the groups before and after the Coast Survey 
explorations. 1 should state that the collections are as yet by no 
means fully worked out; but enough has been done, even in 
the groups least advanced, to show the wonderful richness of 
the collections, not only in new forms, but also in remarkable 
types of special interest. 
Before the explorations of the * Blake" we knew nothing of 
the deep-sea fishes of the Caribbean Sea and of the Gulf of 
