EEPORT OX MATERIALS FROM THE BORINGS AT FUNAFUTI ATOLL. 199 



Polytrema. According to Professor David, the cores distinctly show the characters 

 of a reef rock in situ. 



Details. 



(34). Length 90 millims. Cavernous, mostly of compressed or cylindrical stems of HcHopom co'i idea, 

 laminate Montqiora, and branching Lithothamnioii. The Heliopom is now of a dirty greenish tint, the 

 structure is well preserved, and the tubes of the interior are not infilled. Echinid spines, Polytrema 

 miniacenin, retaining the pinkish tint, P. planum, OrhitolUes. 



(35). Length 55 millims. Hard, compact rock, principally of Heliopora aentlea intergrown with Millepura 

 and Montipova, LithofJiamnion, Serpula. 



(36) [616]. Length 47 millims. Generally similar to preceding, but onlj' Millcpwra and Montipora are 

 present, the corals are overgrown hj Lithotliamnion and some Polytrema planum. The hardened sediment 

 also contains Carp}eideria, P. miidaceum, LejHocliimm stellates, branching fragments of Lithothamnion, and 

 echinid spines. 



(37). Length 73 millims. Very cavernous, hard rock, consisting of clumps of PociUopora sxad Montipoi'a. 

 The Pocillopora is tunnelled by Cliona, &c., the tunnels and the corallites are infilled with white sediment. 

 Lithothamnion, HaJimeda-joints, Polytrema miniaceum, Serpula and echinid spines. 



(38). Length 76 millims., diameter 103 millims. Cavernous, consisting of Millepora, Heliopjora ccendea, 

 Montipora (1), branching Lithothamnion, HaUmeda-joinis, large purplish echinid spines, Serpula, Polytrema 

 ■miniaceum. 



(39-47) [617]. Nine irregular lumps of hard, partly cavernous rock, with a total length of 243 millims. 

 The rock chiefly of the following corals, Millepora, Heliopom cmrulea, Stylophora and Montipora (?). The 

 structure of the Stylophora well preserved ; the coral interspaces partly empty, partly filled with sediment 

 or with prisms of " conchite." It is in places encrusted by Lithothamnion. The hardened sediment contains 

 Orhitoldes, Carpenteiia, Polytrema miniaceum ; stellate spicules of Leptoclinum, and large purple-tinted echinid 

 spines. 



(48). Length 50 millims. Cavernous, hard rock, composed of Millepora, encrusted by Lithothamnion, 

 Heliopora ccerulea and Stylophora. Numerous large purplish echinid spines, sub-triangular in transverse 

 section. 



(49-51) [510, 618]. Length 56 millims. Irregular nodules, of hard compact rock worn by drill, consist- 

 ing of Heliopora ccendea, Stylophora and Montipiora (?). The corals overgrown by finely laminate Lithothamnion 

 and Polytrema planum. In the consolidated mud, Orhifolites, Placopsilina, Planorhdina, Carpenteria, 

 P. miniaceum. 



(52) [619, 619a]. Length 158 millims., diameter 103 millims. Cylindrical core, consisting of a mass of 

 Madrepora contecta, showing in a vertical section the branches completely enveloped by the coenenchyma. 

 The branches, 16-23 millims., in width, are formed of closely arranged, fairly thick-walled, radial corallites, 

 for the most part solidly infilled with sclerenchyma and fibrous carbonate of lime. The coenenchymal 

 interstices in the central portions of the coral are empty, but near the margins they are infilled with 

 sediment. The coral appears to be in its position of growth. 



(53). Length 54 millims. An irregular lump, principally of Mculrepora contecta, encrusted by 

 Ldhothamnion. 



(54). Length 28 millims. A cavernous piece of core with fragments of Heliopirra ccerulea, Pocillopjora, 

 and perforate coral, overgrown by Lithothamnion, Polytrema miniaceum, Serpida. 



(55). Length 147 millims. A massive cylindrical core, cavernous in places, chiefly composed of thick 

 stems and laminate walls of Heliopora carulea and also of Mdlepora. Surrounding the corals are partially 

 consolidated masses of fragmental materials, with Polytrema, echinid spines, (^c. A nearly perfect sea- 

 urchin, determined by Professor Jeffrey Bell to be Cidaris metularia. Lam., occurs in the detritus. 



(55 hiv.). Length 224 millims., diameter 103 millims. Cylindrical core composed of Madrejjora contecta, 



