MUEEAT— DEPTH AND MAEINE DEPOSITS. 



375 



to do this. I, however, did this, and stated that as the bore got deeper and deeper it 

 would resemble more and more materials found in dredgings at a similar depth outside 

 the reef, that the deeper layers would be more dolomitised and would contain more 

 pelagic Poraminifera than the layers nearer the surface. This it appears to me is what 

 the boring indicates : — At the time the deeper layers were laid down they formed the 

 sea-floor at a distance of 350 or 400 yards from the then growing face of the reef; they 

 contain more pelagic organisms because these always increase in abundance as we 

 proceed further from the reef and get into deeper water. My own examination of the 

 bore confirmed my belief that the bore had passed through a portion of the talus 

 produced by the fragments torn from the growing face of the reef, and on which it had 

 proceeded seawards. 



The depth of the boring at Funafuti is 1114 feet ( = 371 yards or 186 fathoms). From 

 the depth of 1100 feet to the bottom of the bore, the material consisted of "solid 

 cylindrical cores of whitish, greyish-white, to greyish-brown, hard, dolomitic limestone, 



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YARDS 



compact to porous, cavernous in places, occasionally efflorescent. The cores consist 

 largely of corals to the horizon of 1109 feet, where there is a change ; the rock becomes 

 whitish, more porous, and it is mainly composed of Foraminifera, with only small corals 

 here and there. This continues to nearly the bottom of the boring, with the exceptional 

 portions where corals are more numerous. The preponderating corals are of the family 

 Astrseidse. . . . The Foraminifera include MilioUna, Orbitolites, Textularia, Olobigerina, 

 Planorbulina, Carpenteria, Calcarina, Gypsina, Polytrema, Amphistegina, and Setero- 

 stegina. There are also echinid spines, Serpula-iViheB, casts of lamellibranchs and 



