REPORT ON iMATERIALS FROM TIJE .BORINGS AT FUNAFUTI ATOLL. 11)1 



The solid cores in this part of the boring, composed as they are mainly of corals, 

 may be considered as indicating the proportion of the general mass of the rock due 

 to these organisms. Making allowance for those which may have decayed or 

 otherwise been reduced to fragments and so have passed into the incoherent ma,terials, 

 it would appear that only about one-fifth of this part of the boring is formed ot 

 corals. 



The greater part of the material from the boring consists of foraminifera and other 

 organisms, chiefly fragmentary, which, together with fine detrital sediment, forms a 

 chalky-looking powder, which, in places, is cemented into hard rock. The greater 

 number of the foraminifera belong to the following genera : — Orhitolites, Carpenteria, 

 Tinopo7'us, Gypsina, Polijtrema, Atnphistegina and Heierostegiiia. The rarer forms, 

 determined by Mr. Chapman, include Nubecularia, MilioUna, Placopsilina, Tladdonia, 

 Tcxtularia, Cristellaria, Sagrina, Glohigerina, Spirillina, Discorhina, Planorhuliua, 

 T7-uncatulina, Pulvinulina and Rotalia. 



The other constituents of the incoherent material are calcisponge spicules, 

 alcyonarian spicules, spines and detached test-plates of echinids, annelid tubes, 

 entomostraca (^Bairdia), limbs of small crabs, polyzoa, brachiopods [Theeidea maxilla), 

 lamellibranchs, gastropods, stellate spicules of ascidians [Leptoclinum) and small 

 coprolitic pellets. The calcareous algse include detached joints of corallines, Halimeda 

 and Lithothamnion, both branching and encrusting. 



Depth from Surface in feet 150-230. Distance Bored in feet 80. 

 Numbers of Corses 138-186. 



The length of the solid cores in this portion of the boring is altogether 9|- feet. 

 The rock is a softer and more porous limestone than that above, and the dissolving 

 away of some of the organisms in it frequently renders it cavernous. The characters 

 are scarcely recognisable except in microscopic sections ; from these it is seen to consist 

 principally of foraminifera, with occasional corals or casts of corals, embedded in 

 fine sediment and consolidated by crystalline calcite. Below the level of 180 feet the 

 corals have undergone an important change, their walls for the most part have been 

 dissolved and removed, and they are now in the condition of casts or moulds of 

 crystalline material, or of fine calcareous sediment, sometimes so friable that it readily 

 crumbles between the fingers. The corals are often overgrown by layers of Litho- 

 thamnion and the encrusting foraminifer, Polytrema p)lctnum, organisms less subject 

 to change in the fossilisation, and their fragile casts are thereby protected to a certain 

 extent, but not infrequently these organic encrustations now only surround a cavity, 

 occupied originally by the coral. This partial destruction and obliteration of the 

 coral structure continues, with some modifications, throughout the remainder of the 

 boring. The forms recognisable in these cores belong to MUlepooxi, HcUop)07xt ccerulea, 



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