576 H. B. GUPPY ON THE RECENT 



composition being described on page 564. They usually, like the coral 

 limestones, are found at the surface ; and in the island of Alu they 

 overlie the soft Pteropod deposits, as described on page 564. In 

 Treasury Island they occur on the tops of the lower hills. 



In the island of Treasury, however, I found exposed in a stream- 

 course a Foraminiferal limestone of somewhat different character, 

 and occupying the usual surface position of the coral limestones. 

 Appended is the description of this rock. 



A hard, compact, grey, Foraminiferal limestone, showing a 

 simple coral imbedded, the whole rock chiefly composed of pelagic 

 Foraminifera. 



Carbonate of Calcium (66 26 per cent.) consists of the following 

 Foraminifera — Globigerina bulloides hirsuta, G. (Orbulina) universa, 

 Pullenia obliquiloculata, Pulvinulina menardii, Amphistegina. 



Residue (3374), brown colour, consists of— 



(a) Minerals (20 '00) m. di. 5 mm. ; felspar, hornblende, 



augite, magnetite, mica, and many glassy fragments. 



(b) Siliceous Organisms (3 -00), casts of Foraminifera. 



(c) Fine Washings (10 -74), argillaceous matter and fine mineral 



particles. 

 The organisms in this rock, together with the minerals, are 

 similar to those found in deposits of modern seas near volcanic 

 islands at depths of from 500 to 800 fathoms. The Foraminifera are 

 identical with those found in the surface waters of the tropics at the 

 present day. 

 (6) The Rhynconella limestone, which was only found in one locality, 

 viz., in the islet of Poperang in the Shortland Islands, may be briefly 

 described as composed of a large number of Brachiopod, Lamelli- 

 branchiate, and Gasteropod shells, together with many simple corals 

 of deep-sea genera imbedded in a matrix largely formed of pelagic 

 Foraminiferous tests. A detailed description of this limestone is 

 given on pages 565 and 566. 



The Occurrence of Flints. 

 This paper would be incomplete without a reference to the occurrence of 

 flints in these islands. They are usually found where the soil has been 

 disturbed for purposes of cultivation ; and I was never successful in finding 

 their source. They occur, however, together with a chalky rock, on the 

 beaches of the island of Ulaua. Having been unable to visit this island, I 

 would recommend future visitors who may land there to pay attention to this 



