PRELIMINARY REPORT. 27 



such a small number of genera, so many small species, and such stunted 

 development of the corals. None of the great heads of the genera so 

 characteristic of the West Indian regions, or of the Gi'eat Barrier Reef 

 of Australia, are to be seen ; with the exception of a couple of species, 

 alcyonaria are absent, so far as our experience shows, and there are but 

 few sponges and gorgonians to be found among the corals. The bathy- 

 metrical limit of the reef-building corals seems to be about twenty to 

 twenty-two fathoms, but nowhere have I seen such extraordinary devel- 

 opment of incrusting nullipores as on the sea edge of the shore platforms 

 of some of the Paumotu atolls, where they build up to a height often 

 of four feet to form the outer edge of the secondary barrier reef so fre- 

 quently seen along the sea reef-faces of the Paumotus. 



Judging from the temperatures taken at various points, 40° F. seems 

 to be found quite generally at about 500 fathoms depth. 



We made a number of surface hauls, as well as intermediate hauls 

 with the tow-nets, but obtained very little animal life in the Paumotus. 

 The poverty of the surface pelagic life and down to 300 fathoms is 

 remarkable. I do not think I have ever sailed over so extensive an 

 area as that of the Paumotus and observed so little surface life ; on calm 

 days, under the most favorable conditions, nothing could be seen with 

 the naked eye, and at night there was little or no phosphorescence. 

 Inside of the lagoons our hauls were equally barren. 



The same paucity of animal life seemed to extend to the deep-water 

 fauna. All the hauls we made off the islands, in from 600 to 1000 

 fathoms, usually the most productive area of a sea slope, brought nothing, 

 or so little that we came to grudge the time spent in trawling on the 

 l)ottom, as well as towing on the surface or near it, — a great contrast to 

 the conditions in the Atlantic in similar latitudes, and very different from 

 our anticipations. 



For these reasons we did not attempt to make a trial of the deep-sea 

 pump while in such unproductive areas; and unfortunately while we were 

 in the region of the equatorial currents the weatber conditions were not 

 suited for a trial of the apparatus. 



