REPOET ON MATERIALS FROM THE BORINGS AT FUNAFUTI ATOLL. 257 



with fine sediment. The coral overgrown by thick layers of Polyirema 2)Ianum and thin alternating layers 

 of Liflwthamnion, both showing minute structure in microscopic section. 



(206a). Length 195 millims. Mottled grey and white, hard, porous to compact. Several casts of 

 corals filled up mth dolomite ; only in one instance, a Madrej)ora, recognisable. Core mainly of detrital 

 material, with foraminifera, of which only Amphlstcgina can be distinguished. Echinid spines. 



(207a). Length 33 millims. AVhitish, porous, with surface efflorescent. Cast of small Sfi/Iojjhora (?), rest 

 of core detrital, like preceding. 



(208a) [739]. Length 248 millims. Whitish, with grey bands and nodular areas, porous, moderately hard. 

 Several indistinct casts of corals, perhaps Madrepwa {1) ; the casts are overgrown by thick layers of Polijfrema 

 planum and some Lithoflmnnion. Greater part of cores of sedimentary materials, with foraminifera and 

 echinid spines. 



(209a). Length 50 millims. Whitish-grey, mottled, hard, compact to porous. Cast of coral overgrown 

 by Polyirema planum. 



(210a). Length 348 millims. Grey and whitish, speckled in places, hard and porous. Indistinct 

 traces of coral in the grey harder portions of the core, which, as usual, are surrounded by layers of 

 Polyirema. Only Madrepora can be distinguished. Core mainly of detrital materials. Amphisiegina and 

 echinid spines can be made out with a lens. The nearly complete obliteration of the corals in these cores 

 seems to be due to the agate-like secondary deposition of crystalline dolomite. 



(211a, 212a). Total length 128 millims. Whitish, soft *o moderately hard, porous. Cast of Madrepom. 

 Greater part of cores of fine fragmentary organic materials, with foraminifera, echinid spines, and casts of 

 lamellibranehs and gastropods. 



(213a) [740]. Length 228 millims. Whitish-grey, hard, mottled, compact to porous, dolomitic lime- 

 stone. Casts of :orals infilled with crystalline material, and overgrown by layers of Polyirema planum. 

 The only coral distinguishable is Astrceopora. Larger part of core of detrital materials with Carpenieria and 

 Amphisiegina ; the former with the wall structure preserved. Echinid spines, Halimeda. 



(214a, 215a). Total length 230 millims. Rock similar to preceding. Obscure traces of corals, 

 surrounded by layers of PGhjirema. Rest of core detrital. 



Depth from Surface, 833-844 /ee/; Distance Bored, 11 feet; Total Length of Core 

 Obtained, 10 feet 6 inches; Numbers of Cores, 216a-234a. 



Cores cylindrical, of a whitish to cream-tinted, hard (H = 4), mostly compact, fine- 

 grained rock. The upper cores to 224a, at 838 feet, are similar to those preceding 

 in being to a considerable extent dolomitic, but below this level the proportion of 

 magnesian carbonate is considerably less, and the rock appears to be mainly of 

 crystalline calcite. The organic constituents of the upper and lower cores are very 

 much of the same character. Corals seem to form only a small part of the rock ; they 

 are, as before, nearly entirely obliterated by the infilling of dolomitic limestone. 

 Only small forms of Stylophora, Astrma, Orbicella (?), and another Astrsean coral, 

 with Madrepora and AstrcBopora, have been distinguished, and these are overgrown 

 by Polytrema planum and Lithothamnion. The larger part of the cores consist of 

 foraminifera and fragmental materials, cemented by dolomite or calcite. Where this 

 latter mineral in part replaces the dolomite at the level of about 838 feet, the 

 foraminifera are better preserved, and more favourably shown in microscopic sections. 

 The forms represented are given below ; the principal change is the reappearance of 



2 L 



