THE WEST INDIAN FAUNA. 6 



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 bathymetrical 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. I 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 



