CALCAREOUS FORMATIONS OF THE SOLOMON GROUP. 581 



Fig. 3. Section of a compact coral limestoine from N.E. side of Treasury Island, consisting almost 

 entirely of crystallised carbonate of lime, and fragments of the following organisms : — 

 Gasteropod and Lamellibrancli shells, Echinaderms, corals, calcareous Algae, Serpula tubes, 

 and Foraminifera of the genera Carpenteria, Polytrema, Tinoporus, Gypsina, Calcarina, 

 Amphistegina, Cijcloclypeus, Nummulltea, Globigerina, and Palvinulina. 



Fig. 4. Section of a compact Rhynconella or Foraminiferal limestone, from Poperang Island (see 

 pages 565 and 566), containing 75'23 per cent, of carbonate of lime, which consists chiefly of 

 pelagic and other Foraminifera, shells of Rhynconella, and fragments of Gasteropods, 

 Lamellibranchs, and Echinoderms. A considerable quantity of the carbonate of lime is 

 crystallised with a rhombohedral cleavage (c). The interior of the Foraminifera shells is 

 frequently filled with a reddish substance. The mineral particles are — (1) fragments of 

 plagioclase very much altered, with the twinning of albite and pericline (d); (2) hornblende, 

 often zonary («), with inclusions of apatite (the little white spot in the section) or twinned 

 (b); and (3) black mica (e). 



VOL. XXXII. PART III. 5 C 



