CAPE-MARIA ISLAND, in Limmen’s Bight, was found by Mr. Brown to be composed principally of sandstone.  The specimens from this place, however, consist of grey splintery hornstone, with traces of a slaty structure; and of yellowish-grey flint, approaching to chalcedony; with a coarse variety of cacholong, containing small nests of quartz crystals.

GROOTE EYLANDT is composed of sandstone, of which two different varieties occur among the specimens.  A quartzose reddish sandstone, of moderately fine grain; and a coarse reddish compound, consisting almost exclusively of worn pebbles of quartz, some of which are more than half an inch in diameter, with a few rounded pebbles of chalcedony.  The latter rock is nearly identical with that of Simms’ Island, near Goulburn’s Island on the north coast.

CHASM ISLAND, WINCHELSEA ISLAND, and BURNEY’S ISLAND, are of the same materials as Groote Eylandt:  and sandstone was found also on the western shore of BLUE-MUD BAY.

On the shore of the mainland, opposite to Groote Eylandt, a little north of latitude 14 degrees, Mr. Brown observed the common sandy calcareous stone, projecting here and there in ragged fragments.

MORGAN’S ISLAND, in Blue-Mud Bay, north-west of Groote Eylandt, is composed principally of clink-stone, sometimes indistinctly columnar.  But among the specimens are also a coarse conglomerate of a dull purplish colour, including pebbles of granular quartz and a fragment of a slaty rock like potstone:  the hue and aspect of the compound being precisely those of the oldest sandstones.  Reddish quartzose sandstone, of uniform and fine grain.  A concretion of rounded quartz pebbles, cemented by ferruginous matter, apparently of recent formation.

ROUND HILL, near Cape Grindall, a prominence east of north from Blue-Mud Bay, was found by Captain Flinders to consist, at the upper part, of sandstone.  The specimens of the rocks in its vicinity are, dark grey granite, somewhat approaching to gneiss, with a few specks of garnet; and a calcareous, probably concretional stone, enclosing the remains of shells, with cavities lined with crystals of calcareous spar.

MOUNT CALEDON, on the mainland, west of Caledon Bay, consists of grey granite, with dark brown mica in small quantity; and on the sides and top of the hill large loose blocks of that rock were observed, resting upon other blocks.

A small island, near Cape Arnhem, is also composed of granite, in which the felspar has a bluish hue.

Smaller of the MELVILLE ISLANDS, north-east of Melville Bay.* A botryoidal mass of ferruginous oxide of manganese, approaching to hematite; the fissures in some places occupied by carbonate of lime.

(Footnote.  The relative position of the islands and bays on this part of the coast is represented in the enlarged Map.)

MELVILLE BAY.  Granite, composed of grey and somewhat bluish felspar, dark brown mica, and a little quartz; containing minute disseminated specks of molybdena, and indistinct crystals of pale red garnet.