Eeviews— The AMI of Funafuti. 225 



by means of a lens, whilst fov the examination of the minute forms 

 and of the mineral chai-actex*s of the rock, more than 500 microscopic 

 sections were prepared. 



In addition to the materials from the borings, large collections 

 of the existing fauna and flora of the atoll were made by Mr. Stanley 

 Grardiner and Mr. Hedley, and Professor David and Mr. G. Sweet 

 made strenuous efforts, at no small personal risk, to dredge up the 

 organisms existing on the steep ocean slopes of the present reef to 

 a depth of 200 fathoms. Asa description of the existing organisms 

 of the atoll was not included in the scope of the undertaking, the 

 collections made have been, in part, studied by different specialists 

 in this country and in Australia, and the results published in 

 various scientific journals. A list of these memoirs is given by 

 Professor Judd. 



Section xi, by Dr. G. J. Hinde, F.R.S., contains the report on 

 the materials from the borings at the Funafuti Atoll. 



The main achievement of the later expeditions to Funafuti, under 

 the direction of Professor David and Messrs. Finckh and Sweet, 

 was the penetration of the reef at the main boring to a depth of 

 1,114 feet and obtaining materials which showed distinctly the 

 nature of the rock to this depth. These materials were subjected 

 to very careful scrutiny, and a detailed record of the various 

 organisms recognized in each separate portion of the cores and their 

 general mineral condition is given in this section of the Report. 

 The nature of the material varied greatly in different parts of the 

 boring. To the depth of 748 feet from the surface the greater part 

 of the rock seems to have been of a friable and incoherent character, 

 which in the process of boring was reduced to fine granular particles 

 usually called sand, whilst the aggregate length of the solid portions 

 of the core only reached 73 feet, or about one-tenth of the distance 

 passed through. On the other hand, the lower third of the boring 

 from 748 feet to the bottom at 1,114 feet was to a very large extent 

 solid rock, forming a nearly continuous cylindrical core 311 feet 

 in length. The friable upper portion down to 637 feet w^as mainly 

 of calcium carbonate, whilst the lower solid third of the core was 

 of dolomitic limestone. 



No true oolitic grains were met with in any part of the cores^ 

 nor was any pumice or other volcanic material recognized. The 

 presence of silica was not detected, though siliceous boring sponges 

 were originally very numerous. Lines of stratification were not 

 distinguished in the cores. 



The rock throughout was entirely organic, derived from the 

 calcareous skeletons of marine invertebrate animals and calcareous 

 algae ; the principal rock-formers belong to Foramiuifera, Corals^ 

 and Algse, and with these are associated detached spines and test- 

 plates of echinoderms, annelid tubes, crustacean tests, spicules of 

 calcisponges and tunicates, and the shells or casts of lamellibranchs 

 and gasteropods. The only vertebrate remains found in the cores was 

 a single fragment of fish-bone or spine less than an inch in length. 



Of the Foramiuifera 35 genera ai'e represented in the main boring ; 



DECADE V. VOL. I. NO. V. 15 



