262 Transactions. 



hypersthene in' grains strongly pleocliroic in pink and green, and a little 

 augite. 



Efidote Gneiss (G 3). — From head of Gaer Arm. Tliis is a rock com- 

 posed of feldspar frequently in foliee, with dark foHee of hornblende and 

 mica, and very prominent yellowish-green epidote grains. In section, 

 epidote in large grains and needles appears to be the most prominent con- 

 stituent, greenish hornblende and brown mica, with much sphene, in grains 

 and idiomorphic crystals. There is much feldspar (ohgoclase) and some 

 quartz, but some of the apparent quartz is clear colourless feldspar ; apatite 

 occurs in short needles.^,^,-^'!^'^'*' 



Feldsfar Quartz Rock (G 4). — From the head of Gaer Arm. This is a 

 white rock, which appears in section to be composed of plates of oligoclase, 

 large grains of quartz exhibiting undulose extinction, and small amounts of 

 muscovite and epidote. 



Mica-schist (G 5). — From Wood Head, at the junction of Doubtful and 

 Thompson Sounds. In the hand-specimen this appears as a dark-grey 

 schistose rock with lustrous mica surfaces, not very distinctly fohated. 

 Under the microscope it shows well-marked parallel arrangement of the 

 elements, which are almost wholly quartz, with brown and white mica ; 

 a httle turbid feldspar occurs, and grains of ilmenite and haematite. This 

 rock is in all probability an altered sediment. 



Diorite Gneiss (G 5). — From Wood Head. A rock composed of feldspar 

 with speckles of dark - coloured constituents, schistose in structiire. The 

 microscope shows the presence of feldspar frequently clear and colourless 

 and resembling quartz, a small amount of quartz being undoubtedly pre- 

 sent ; the other constituents are greenish mica, much greenish hornblende, 

 epidote in grains, ilmenite passing into leucoxene, and anhedral rutile in 

 sufficiently large grains to show a uniaxial interference figure ; apatite 

 needles also occur. 



Hornblende Schist (G 8). — From Deas Cove. A dark-coloured rock show- 

 ing in section that four-fifths of the rock is yellowish-green hornblende 

 slightly pleochroic ; some feldspar occurs, and a little quartz in grains, but 

 the amount is quite subordinate ; grains of rutile are very common. This 

 rock is evidently the same as Marshall's G 26. 



Gneiss (G 10). — From Deas Cove.|. This is a white rock composed oi 

 quartz in rounded grains, much microcline, oligoclase, numerous shreds of 

 muscovite, and very occasional garnets. Areas exhibiting granophyric 

 intergrowths occur, strain-efiects are common, and morter structure is well 

 shown in places. 



Another specimen (G 9) from the same locahty is very similar, but con- 

 tains biotite and a httle muscovite and less microchne. This appears to 

 be Hke Marshall's A 9. 



i' ^ ^j H George Sound. 



The specimens were collected at the head of the Soimd, near the track 

 to Lake Te Anau. 



Gneiss (G 6). — A light -grey rock, not distinctly fohated. In section 

 it is composed of clear feldspar (ohgoclase), with some untwiimed feld- 

 spar probably orthoclase ; much quartz ; much epidote in large grains : 

 both muscovite and biotite occur, and sphene in grains. The structure^is 

 slightly cataclastic. . ! 



