about fifty or sixty feet in height was covered with a sandy calcareous stone, having the appearance of 'concretions rising irregularly about a foot above the general surface, without any distinct ramifications.' The specimens from this place have evidently the structure of stalactites, which seem to have been formed in send; and the reddish carbonate of lime, by which the sand has been agglutinated, is of the same character with that of the west coast, where a similar concreted limestone occurs in great abundance.
The western shore of the Gulf of Carpentaria is somewhat higher, and from Limmen's Bight to the latitude of Groote Eylandt, is lined by a range of low hills. On the north of the latter place, the coast becomes irregular and broken; the base of the country apparently consisting of primitive rocks, end the upper part of the hills of a reddish sandstone;—some of the specimens of which are identical with that which occurs at Goulburn and Sims Islands on the north coast,?and is very widely distributed on the north-west. The shore at the bottom of Melville Bay is stated by Captain Flinders to consist of low cliffs of pipe-clay, for a space of about eight miles in extent from east to west; and similar cliffs of pipe-clay are described as occurring at Goalburn Islands, (see the plate, vol. i. p. 66,) and at Lethbridge Bay, on the north of Melville Island; both of which places are considerably to the west of the Gulf of Carpentaria.
Morgan's Island, a small islet in Blue-Mud Bay, on the north-west of Groote Eylandt, is composed of clink-stone; and other rocks of the trap-formation occur in several places on this coast.
The north of Blue-Mud Bay has furnished also specimens of ancient sandstone; with columnar rooks, probably of clink-stone. Round Hill, near Point Grindall, a promontory
