battery. Cox, Reports Geol. Explorations, p. 16, Sect. No. 2 

 (Dioritic Rock). 



^ Komiti Peninsula, Kaipara. — A greyish-black, compact, sub- 

 vitreous rock, with scattered small white felspars. S.G. 264. 

 Section : Ground-mass very abundant, crystallitic, longulitic, in a 

 brownish glass ; crowded with minute felspar microlites and a few 

 magnetite grains ; no fluxion structure. The porphyritic minerals 

 are plagioclase and augite, the former going to -04, the latter to 

 •02 in length. Park, Reports Geol. Expl. 1885, p. 167, and 1886-7, 

 p. 220. 



Enstatite Andesite. 



Malvern Hills, Selwyn Cq.—K greyish-black sub-vitreous rock 

 with small scattered felspars. S.G. 2-66. Section : Ground-mass 

 moderate, crystallitic, globulitic, with scattered felspar microlites 

 not shewing fluxion. The porphyritic minerals are plagioclase, 

 augite, and enstatite. The plagioclase goes up to -07 in length, 

 and is partly in ophitic plates enclosing augite and enstatite. The 

 augite is allotriomorphic, in large grains only. The enstatite is 

 colourless or pale green, and not pleochroic ; it has low polarization 

 colours and is not much cleaved, often idiomorphic, the crystals 

 going to -04 in length and giving straight extinctions. There is 

 also a little chlorite. Snowy Peak. Haast., Rep. Geol. Expl. 

 1870-1, p. 12; Cox, I.e., 1883-4, p. 35. 



Siigarloaves, Taranaki. — A fine grained, grey rock, with numer- 

 ous small white felspars and scattered small pyroxenes. S.G. 2-69. 

 Section : Ground-mass moderate, crystallitic, longulitic, the glass 

 colourless ; with scattered felspar microlites and numerous grains 

 of magnetite. The porphyritic minerals are plagioclase, augite, 

 enstatite, and magnetite. The plagioclase is zoned and goes up to 

 •07 in length. The augite is pale greenish, up to -04. The ensta- 

 tite is subordinate to the augite ; it goes up to -03 in length ; it 

 IS distinctly pleochroic changing from pale yellowish-brown to 

 reddish-brown. 



Ruapehu. — 1. A grey compact rock with scattered small 

 pyroxenes and occasionally rather conspicuous felspars. S.G. 2-66. 

 Section : Ground-mass abundant, crystallitic, longulitic, the glass 

 pale; crowded with microlites of felspar and augite shewing 

 fluxion, as well as magnetite grains. The porphyritic minerals 

 are plagioclase, (-05), greenish augite (-04) and enstatite (-06). 

 The last is pleochroic, changing from brown to blue-"reen. From 

 the south-east slopes of the Mountain. 



2. Dark grey rock with scattered felspars and pyroxenes, not 

 conspicuous Another specimen is reddish-brown with conspicu- 

 ous pyroxenes but no felspars. S.G. 2-60. Section : Ground-nui- 

 abundant, crystallitic, globulitic, opaque with grains of eith'"- 

 magnetite or haematite. The porpliyritic minerals are plagiocla--- 



