42 BULLETIN: MUSEUM OE COMPARATIVE ZOOLOGY. 



11. Levuka. Specific gravity, 2.8. Very compact andesite agglom- 

 erate, almost identical with (8). 



Mr. W. E. Wooluough, B. Sc. of Sydney University, has kindly 

 examined and described No. 12. 



Xo. 12. Suva. Specific gravity, 2.84. Olivine dolerite. 



Plagioclase by far the most abundant constituent of the rock, making 

 it almost andesitic. They take the form of large tabular crystals with 

 abundant concentric-zoned inclusions, mainly magnetite and a little 

 apatite. The zoning is very perfect. Augite is present in large yellow 

 idiomorphic crystals showing twinning and traces of ophitic structure. 



The olivine present is a highly ferriferous variety, some of the crystals 

 being blood-red. Most of the olivine is in the form of large grains, some 

 show distinct outlines. Some of it is almost undecomposed, while some 

 is almost opaque with secondary serpentine and iron-oxides. 



The magnetite recurs in scattered grains, and is distributed abundantly 

 throughout the ground mass, which is crypto-crystalline to glassy in 

 texture. In one cavity there is a mass of small spherulites of a zeolite. 

 These give under crossed nicols a dark cross at about 30° with the prin- 

 cipal planes of the nicols. 



13. Mango. Specific gravity, 2.75. Selected from compact andesite 

 flow. Shows the usual structure and appearance of plagioclase. The 

 pyroxenes are altered ; some show beautiful 8-sided crystals. Much 

 magnetite present. 



14. Taviuni. Specific gravity, 2.70. Selected from vesicular andesite 

 Under microscope shows two crops of felspar in glassy base. Great 

 development of magnetite. 



15. Taviuni. Specific gravity, 2.72. Vesicular olivine basalt. The 

 olivines are quite fresh. Crop of lath-shaped felspars. 



16. Mania. Specific gravity, 2.70. Taken from an andesite agglom- 

 erate. Dark-colored rock showing usual two crops of plagioclase in fine 

 base. Pyroxenes are altered. 



The following three rock slides were described by Mr. W. E. Wool- 

 nough, B. Sc, of Sydney University. 



17. Loma Loma. Specific gravity, 2.92. This appears to be a coarse 

 dolerite with phenocrysts of striated felspar, and apparently greenish 

 pseudomorphs after olivine. 



18. Sicva. Specific gravity, 2.57. A rhyolite. 



Groundmass is crypto-crystalline, containing abundant grains of 

 limonite, also containing very abundant small spherulites which are 

 quite free from limonite. 



