Vol. 70.] LAVAS AT TILE NORTH HEAD, OTAGO IIAEBOUE. -391 



minerals, but infrequent, 17 X 1 '2 mm. Olivine rather frequent, 

 idiomorphic. 1 mm. 



Ground-mass : labradorite-mierolites, - 1 X '01 mm., 6 per cent. ; 

 pale-green augite, '08 X '04 mm., 25 per cent. ; magnetite, '04 mm., 

 5 per cent. 



(10) Basalt. — Phenocrysts of labradorite, few, '5x1 mm.; 

 augite more abundant, brown, lxl mm. ; olivine, sometimes 

 idiomorphic, 1 X '8 mm. 



Ground-mass : acid labradorite, '15 x "08 mm., 57 per cent. ; 

 pale-green augite, -01- x '01 mm., 28 per cent. ; magnetite, "032 mm., 



15 per cent. 



(9) Basalt. — Labradorite-phenocrysts not numerous, small, 

 1 X '05 mm. ; augite, a few brown crystals. 1 X '5 mm. ; olivine 

 serpentinized, in round grains measuring "5 mm. in diameter. 



Ground-mass: labradorite, '3 X 03 mm., 5-4 per cent.; augite, 

 '03 x '05 mm.. 33 per cent.; magnetite, '05 mm., 13 per cent. 

 A few crystals of brown apatite. 



(8) Basalt. — Phenocrysts few, mainly labradorite, '8 x '4 mm. 



Ground-mass : labradorite, '16 X '02 mm., 47 per cent. ; augite 

 very pale green, rounded or short crystals, "01 X '006 mm., 35 per 

 cent. ; magnetite '004 mm., 14 per cent. ; some rounded grains of 

 olivine, 5 per cent. 



(7) Basalt. — No phenociysts. 



Ground-mass : labradorite, '3 x '02 mm., 48 per cent. ; pale- 

 green augite, -025 x '006 mm., 36 per cent. ; magnetite, '006 mm., 



16 per cent. ; olivine idiomorphic, rather sparingly present. 



(6) Basalt. — Felspar-phenocrysts almost absent; augite fre- 

 quent, 3x2 mm., well zoned, sometimes exhibiting hour-glass 

 structure and twinned ; olivine abundant, 2x1 mm. 



Ground-mass : labradorite-laths '12 x '02 mm., 60 per cent. ; 

 pale-green augite, '08 X '01 mm., '15 per cent. ; olivine, rounded 

 grains, '04 mm., 10 per cent. ; magnetite, '04 mm., 15 per cent. 



(5) Basalt. — Phenociysts of oligoclase and anorthoclase, 

 •4x3 mm. ; augite brown, with occasionally a greenish centre, 

 3 X 1 mm. — a tendency to hour-glass structure is fairly frequent ; 

 olivine very scarce and in small grains, '2 mm. ; perofskite occurs 

 in distinct crystals, measuring '1 mm. 



Ground-mass: acid-la bra dorite. '8 X '005 mm., 68 per cent.; 

 pale-green augite, '04 x '008 mm., 21 per cent. ; magnetite and 

 perofskite, '008 mm., 11 per cent. 



(4) Basalt. — Felspar-phenocrysts. apparently belonging to anor- 

 thoclase, oligoclase, and labradorite, '5 X 2 mm. ; brown augite, 

 slightly pleochroic, sometimes twinned, 1 X '5 mm. ; olivine 

 roundish, much oxidized, 1 mm. 



