724 
No. 309. ViCTOEiA : Omeo. 
P. Platt’s Collection. Sp. Gr. 2'71. 
Greyisli-blaek. Compact. 
Section . — V compact basalt, with lath-like felspars, doubtful olivine, and grains 
of magnetite. A yellow isotropic glass occurs amongst the crystals, h luxion-structure. 
A yellow envelope, precisely similar to the above, encloses an augite crystal, which has 
symptoms of spherulitic structure. 
No. 310. Baulaeat (Victoeia). 
P. Platt’s Collection. Sp. Gr. 2'54. 
Grevish-black. Compact basalt from core of diamond drill. 
Section . — The texture is nearly the same as the above (No. 309), but the slice 
is too thick for much keen observation. The yellow isotropic mineral is rare. 
DOLEEITES. 
No. 47. Goran (New South Wales). 
The late Mr. C. S. Wilkinson’s Collection. Sp. Gr. 2-964. 
Black. This is a compact basalt, speckled with white crystals. 
Section . — The rock is granular, idiomorphic and holocrystalline. The plagioclase 
felspars are often '03 inch by '002 inch, and the majority are a pale-lavender, with very 
small angles of extinction between the sets of lamella), which latter are repeated many 
times in all of the crystals. Other plagioclases have high angles of extinction, and 
polarize in higher colours — i.e., in light yellow and orange. The latter often exhibit 
undulose polarization. 
Olivine somewhat large and fresh. Augite granular, with granulitic structure 
as defined in Professor Hutton’s Paper before alluded to. Magnetite sparse. Very 
little apatite, and no interstitial glass. 
No. 35. AVolloh&ohg (New South Wales). 
The late Mr. C. S. Wilkinson’s Collection. Sp. Gr. 2-778. 
Colour, brownish black. 
Semi-crystalline, the -lath-shaped felspars being separated from each 
other by felsitic matter. Magnetite and perhaps titaniferous iron most abundant. 
Augitic matter in very small granules, and not abundant. There is no interstitial glass. 
Nos. 18 AHD 19. Sellheim Silvee MijfES (Queensland). 
(No. 18 is from the surface, and No. 19 from 30 feet depth.) 
B. L. Jack’s Collection. Sp. Gt. of No. 18, 2-854. 
Colour, dark-grey, speckled with what looks like hornblende. 
Section . — Both show similar contained minerals, with the exception of hydrated 
iron oxides, which are abundant in No. 18. The minerals are so altered that even on the 
thinnest feather-edge there is nothing very clear or worthy of description. The rock is 
mainly composed of lath-shaped felspars, some being tabular and frame-shaped. Keedles 
of apatite are plentiful, in fact I have never seen a rock-section so crowded with this 
mineral. In a single group of quartz crystals, there is a continuous band -22 inch long, 
containing apatites, cut parallel and at right-angles to o P. They are of various sizes, 
ranging from the finest hair up to prisms -001 inch in diameter, and from -02 inch to 
•03 inch in length. 
