in bold fantastic outlines ; they rise very aliruptly out of the 

 sandy plain, and are very little, or not at all, covered with vege- 

 tation. At the south-western base of the range, and in the wide 

 plain-like valleys which are protected from drifting sand, there are 

 winding creeks and flood-channels ; here herbage and timber is 

 abundant, and a fair supply of surface-water is obtainable. The 

 water-supply could, however, be considerably increased by dam- 

 ming the narrow gullies, and by sinking to the subterranean 

 basins which intervene between the hills. The continuously- 

 elevated ground occupies a large area, and outlying portions of 

 the range occur at considerable distances away from it. 



The western, more than the eastern section of the range, is 

 penetrated by hornblendic rocks ; this feature is well-displayed in 

 Mount Agnes and Blyth Hill (see fig. 2, pi. 2), the latter of which 

 has a back-bone of diorite running right through it. The Blyth 

 Range of Gosse, ill-defined by him, is now proved to be an out- 

 lying part of the Birksgate Range, and is degraded by Mr. D. 

 Lindsay to the rank of Blyth Hill. 



Mount Watson is a dome-like mass of imposing aspect (see 

 fig. 5, pi. 3), 2,200 feet high, and 726 feet above the surrounding 

 plain ; Mount Sir Thomas, the highest elevation of the Birksgate 

 Range, is 2,535 feet above sea-level, and 680 feet above the 

 plain; Blyth Hill is 2,300 feet above sea-level, and 550 feet 

 above the level of the plain, as determined by Mr. Lindsay. 

 The mean, elevation of the plain, deducible from the above 

 figures, is 1,700 feet above the level of the sea. 



The soil in the wide valleys of the Birksgate Range is of a 

 rich loamy nature, and principally overlies travertine ; beyond 

 them drift sand, clothed with a luxuriant growth of porcupine- 

 grass, is prevalent. 



Geologically and physiographically the stretch of country which 

 ends in Mount Agnes is a moderately elevated granitic upheaval, 

 roughly parallel with the Musgrave and Maodonnell Ranges. It 

 is largely covered with alluvial deposits, which allow only the 

 summits of the axis of elevation to be visible, i Two of these 

 masses are especially prominent ; the western one is composed of 

 the Birksgate Range and its spurs, the eastern one of the 

 Everard Range and its numerous outliers ; the latter is 

 probably connected with the Musgrave Range to the north. 



From Camp 24 the elevation of the spinifex-plain declines 

 westward to the base of Skirmish Hill, where on Moses Creek the 

 depression reaches its minimum of 1,335 feet above sea-level, 

 as determined by the hypsometer, representing a fall of about 400 

 feet in from 40 to 50 miles. 



Skirmish Hill is a somewhat isolated eminence, 580 feet above 

 the plain at its eastern base. Though it is apparently connected 



