RED CLIFFS, south-west of Arnhem Bay; on the line of the first chain of islands mentioned by Captain Flinders. (See the Map, figure 3.) Friable conglomerate, of a full brick-red colour, consisting of minute grains of quartz, with a large proportion of ochreous matter.

MALLISON’S ISLAND. (Map, figure 4.) The cliffs of this island are composed of a fissile primitive rock, on which sandstone reposes in regular beds.  The specimen of the former resembles gneiss, or mica slate, near the contact with granite:  the sandstone is thick-slaty, quartzose, of a reddish hue, with mica disseminated on the surfaces of the joints; and one face of the specimen is incrusted with quartz crystals, thinly coated with botryoidal hematite.  Light grey quartzose sandstone of a fine grain, with a thin coating of brown hematite, was also found in this island:  And a breccia, consisting of angular fragments of sandstone, cemented by thin, vein-like, coatings of dark brown hematite, was found there, in loose blocks at the bottom of perpendicular cliffs.  The specimen of this breccia is attached to a plate of granular quartz, and may possibly have been part of a vein.

The shore of INGLIS’ ISLAND, the largest of the ENGLISH COMPANY’S RANGE (2. 2. 2. in the Map) is formed of flat beds, of a slaty argillaceous rock, which breaks into rhomboidal fragments; but the specimen is indistinct.  Ferruginous masses, probably consisting of brown hematite, come also from this island.

ASTELL’S ISLAND, north-east of Inglis’ Isle.  Very fine-grained greyish-white quartzose sandstone; identical with that of Mallison’s Island, and very closely resembling some of the specimens from Prince Regent’s and Hunter’s Rivers.

Among the remaining islands of this range, BOSANQUET’S, COTTON’S, and POBASSOO’s Isles, were found by Mr. Brown to consist, in a great measure, of sandstone, of the same character with the specimens above-mentioned.

POBASSOO’S ISLAND, a small islet south-east of Astell’s Isle.  Fine-grained, somewhat reddish, sandstone.  Another specimen of sandstone is friable, of a light flesh-red colour, and apparently composed of the debris of granite.  A crystalline rock, consisting of greenish-grey hornblende, with a very small proportion of felspar (Hornblende rock ?).  Fragment, apparently from a columnar mass, of a stone intermediate between clink-stone and compact felspar.

Such of the English Company’s Islands as were examined by Captain Flinders, are stated by him to consist, in the upper part, of a grit, or sandstone, of a close texture; the lower part being argillaceous, and stratified, and separating into pieces of a reddish colour, resembling flat tiles.  The strata-dip to the west, at an angle of about 15 degrees.