Geological Society. 463 



Carpentaria, and are remarkable for the similarity of their 

 sti'iicture and their uniform direction, appear to consist prin- 

 cipally of qiiartzose sandstone and conglomerate, reposing 

 upon primitive rocks. The level of the mainland of the north 

 coast from about longitude 135" to Melville Island, about 131°, 

 is in general low, and is interrupted by the streams named Li- 

 verpool and Alligators Rivers; the last of which consists, in 

 fact, of three separate streams or branches. 



The specimens from Gouldburn's Islands, on the north of 

 this part of the coast, consist of reddish quartzose sandstone. 



Cambridge Gulf, about longitude 128° and latitude lo"", is 

 one of the most remarkable inlets on the north-west of Au- 

 stralia. It has been traced to more than 60 miles from the 

 sea, between hills from 150 to 400 feet in height, which have 

 in general flat summits, and are composed of sandstone of a 

 reddish hue and of the same characters with that already men- 

 tioned. The specimens from Lacrosse Island, at the entrance 

 of this Gulf, are not to be distinguished from the slaty strata 

 of the old red sandstone which occur in the banks of the Avon, 

 between Clifton and the Severn. 



The outline of the north-west coast is remarkably broken ; 

 and the shore is studded with very numerous islands ; the 

 forms of which, as well as of the hills on the mainland, are 

 remarkable for their flat summits. In two detached points 

 about 70 miles apart, Port Warrender and Careening Bay, 

 epidote has been found in considerable quantity, both cry- 

 stallized in veins, and in a compact form as a component of a 

 rock of a conglomerated and amygdaloidal structure. Prince 

 Regent's River has nearly a rectilinear course, from north-west 

 to south-east, for more than 60 miles ; and its banks of sand- 

 stone are in some places between SPO and 400 feet high. The 

 coast to the south-west of Prince Regent's River has not yet 

 been completely surveyed ; but several openings have been ob- 

 served there, of such width as to render the existence of rivers 

 not improbable. 



The shore on the western coast is in several places covered 

 with extensive dunes of sand, with which are associated in 

 many instances beds anil masses of a very recent arenaceous 

 breccia, abounding in shells, concreted by carbonate of lime. 

 This formation, which is particularly remarkable in the islands 

 and on the shores adjacent to Shark's Bay, about latitude 25°, 

 is analogous to that which occurs very extensively in Sicily, 

 at Nice, and seveial other places on the shores of the Medi- 

 terranean, and of the West India Islands, and on many parts 

 of the coasts within the Tropics. In New Holland it generally 

 consists of sand cemented by stalagmitic or tufaceous car- 

 bonate 



