THE GEOLOGY OF MITTAGONG. 329 
Magnetite is present in small black opaque grains, some- 
times it is aggregated into a long narrow row of grains. 
It is also included in both clear and kaolinised felspars and 
is often surrounded bya border of brownish matter, due to 
the colouring of the kaolin by iron. The magnetite is best 
examined by reflected light which also shows up the kaolin 
well. 
Grains of ilmenite are common, and are invariably partly 
altered into leucoxene. Small grains of the latter are 
scattered through the section, and in reflected light, stand 
out a purer white than the kaolin. 
Among accessory minerals apatite is very abundant as 
small needle-shaped prisms and hexagonal basal sections. 
These prisms occur in small bunches in the felspars. Central 
enclosures of higher refractive index occur in the needles. 
Fluorspar as irregular blue isotropic patches is present. 
Calcite and granules of chalcedony line irregular spaces 
in some slides. These however are obviously secondary. 
Order of Consolidation. 
Apatite 
Magnetite Ilmenite 
Hornblende ? 
Orthoclase 
| Fluorspar 
| Calcite 
| Chalcedony 
, Name.—The rock is a SYENITE allied to bostonite. The 
latter (vide Harker, p. 117) is a rock consisting essentially 
of felspar, the ferromagnesian silicates being typically 
absent. According to the new classification based on 
chemical analysis the rock is named boxolanose. 
V—Oct. 7, 1903. 
