REPOET ON MATERIALS FROM THE BORINGS AT FIFNAFUTI ATOLL. 283 



Hckro^ffflinn. Echinid spines, Serpula, and nodular Liihothainninn. The small organisms and fragments 

 are coated hj numerous, thin successive layers of crystalline dolomite which cements them together. 



(535a). Length 425 millims. Greyish-brown, very hard and dense, dolomitic rock, compact to porous, 

 with irregular hollows. Many easts of corals, for the most part replaced by crystalline material and very 

 obsciu'ely shown. PoriUopora, Scriafopora, Cirloria, Jxtnra,_ Mndrrpora, find Monfi/iora. Alcyonarian sjncules. 

 Millejmm. Foraminifera not distinguishable, beyond encrusting Pohitrciiid, jilatnmi. Cliona. borings. 

 Branching Lifhofhaiiniioii, very common. 



(536a). Length 337 millims. Rock similar to the preceding. Many casts of corals ; they are, as a rule, 

 small forms belonging to Stijlopliora, an Astrsean, Mwlrcporu., Montipora, Poriks arenom, and Astrceopora. 

 Only Orbifolifcs, Poh/frcDM, and Ainpild^fi'gina recognised with a lens. Much branching and fragmental 

 Lithoihainnion. Casts of gastropods. Alcyonarian spicules. 



(537a, 538a) [805]. Total length 305 millims. Greyish to greyish-brown, compact to minutely porous, 

 occasionally cavernous. Casts of small corals ; Porillopom, Scriatopora, Asfrim, Orhkdla pleiades, Ellis, 

 Madrepiom, Porifc't. Alcyonarian spicules. Fragmental materials with Miliolina, Orhitolifes, Gaudryina, 

 Carpenteria (1), Pohjtrcma minimeuin, and Aniplmtegina. Echinid spines. Halimeda. Encrusting and 

 branching Lithothamnion. 



(539a, 540a). Total length 382 millims. Greyish rock, like preceding, Nimierous casts of corals. 

 Stylophora, Pocillupora, OrhiceUa pleiades, Madvepora, and Pontes arenosa. Detrital materials with Orbitulites 

 and Polytrema. Lithothamnion. Casts of lamellibranchs. 



(54L\, 542a). Total length 294 millims. Greyish-brown, very hard, generally compact, dolomitic rock, 

 with some irregular hollows. Casts of corals as in preceding cores ; for the most part the corals are 

 replaced by crystalline dolomite. Stj/hphom, PodUopora, OrhiceUa pleiades, Astrsean, Madrepora, and Porifes 

 arenosa. The only foraminifera recognised are Orhitolites a,ud Amphistecjina. Echinid spines. SerpulaAvihe& . 

 Casts of lamellibranchs. Haliin/'dti-jomts. Encrusting and branching Lithothamnion. 



Depth from Surface, 1015-1025/66^; Distance Bored, \Ofeet; Toted Length of Core 

 Obtained, 8 feet 3 inches ; Niconbe^'s of Cores, 543a-564a. 



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

 limestone, partly compact, partly porous with irregular cavities. The character of 

 the rock is very similar to that of the cores immediately above ; corals are present 

 throughout, sometimes sufficiently numerous to form the larger part of the rock, 

 while in other portions they are few, and small in proportion to the minute detrital 

 fragments and foraminifera. They are, as usual, rej^laced by crystalline dolomite and 

 scarcely recognizable. The following genera are present : Stylophora and PodUopora, 

 both very common, Cceloria, Astrcea, OrhiceUa, Fungici, Siderai^trcea, Madrepora, 

 Porites, Montipo7'a, and Astrmopora (?). MiUepoixi, alcyonarian spicules. The 

 foraminifera include Textularia, Orhitolites, Carpenteria, Pulvinulina, Gypsina, 

 Polytrema and Am^phistegina. Echinid spines, casts of gastropods and lamellibranchs. 

 Halim^eda-^ouits, and Lithothamnion. 



Details. 



(543a-546a). Total length 304 millims. Greyish to greyish-brown, compact to porous. Mainly of corals, 

 partly porous, partly infilled and replaced by crystalline material. Stylophrra, PodUopora, large Coelwia in 

 position of growth ; Porites and other forms not determinable. Millepora. Orhitolites, Aniplmtegina. Echinid 

 spines. Casts of gastropods and lamellibranchs. Lithothamnion. 



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