720 
with fine black lustrous grains, which are magnetite, as was found by testing a washed 
sample of the ^^ounded rock, and trying it with a magnetised sewing needle in a watch- 
glass full of water under the microscope. There is a great deal of interstitial glass and 
fine felspar microlites. Leucite occurs sparsely in small six and eight-sided sections. 
Often in these crystals there is a central mass of inclusions consisting of magnetite and 
microlithic felspars, leaving a glass-like hexagon or octagon perfectly free from any 
inclusions, but with the angles generally rounded. But for this feature I might have 
passed it over, but when once seen in the slice it becomes striking. The wearing of the 
angles of leucite is noted by TealL* No quartz or augite, and no fluxion-structure. 
No. 75. Eusskll Eitee (Queejvsland). 
E. L. Jack’s Collection. Sp. Gr. 2'SG4. 
Colour, black. Compact. The fine crystals cause it to sparkle in the light. 
The weathered surface is earthy, and coloured dirty yellow. Absorbent to the tongue. 
Section. Ground-mass glassy, matted with felspars, and perhaps very minute 
augite (?) grains, sharp grains of magnetite and granular serpentine, &c. The section 
is not thin enough for accuracy in these determinations. Olivine in fairly large crystals 
undergoing alleration to serpentine, is the only porphyritic constituent. The felspar 
microlites in the ground-mass measure about '01 inch by ‘001 inch. Plate 65, fig. 1, 
shows the olivines, the largest of which has a hole through it, which, of course, appears 
black between the crossed nicols. The drawing shows the confused aspect of the base^ 
owing to the thickness of the section. Quartz absent. 
No. 167. SuEPEisE Cheek, Herbestoit (QueeksiiANd). 
E. L. Jack’s Collection. Sp. Gr. 2'64. 
Colour, gray, with reddish-brown specks. Vesicular, with zeolites. 
Section.— y&rj rich in augite grains, which are about '001 inch in diameter, 
plagioclase felspars and delicate microlitic needles permeating the felspars. No quartz, 
and very little glass. The jilagioclases arc usually '02 inch long, and each is banded 
three or four times. The only porphyritic crystals are much cracked. Augites invariably 
enveloped in a red mineral of secondary origin. The augites carry minute enclosures 
of glass and magnetite. Sometimes the secondary mineral has completely taken the 
place of the augite. No orthoclase. Eich in magnetite, which occurs as sharp grains. 
The rock would be better classed as anamesite than as basalt, all the constituent 
minerals being of large size. 
No. 169. “VoLCASic Hue,” in Peterson’s Pocket, Herbeeton (Queensland). 
E. L. Jack’s Collection. Sp. Gr. 2’291. 
Colour, black. Vesicular, with grey streak. 
Section.— Yerj vesicular, with large, fresh, much-cracked augite, sections of 
which, parallel to clinopinakoid, have an angle of extinction of 25° 30'. Very fine- 
grained ground-mass of microlithic felspars, and literally swarming with magnetite. 
Magnetite and glass are the only enclosures in the augite. 
• “ British Petrograirhy,” p. 3fi6. 
