THE DESERT SANDSTONE. 293 



consists of horizontal sandstones and conglomerates, which have 

 undergone comparatively little change." 



In Mr. A. Gregory's report on the results of his expedition up 

 the Victoria River in 1855, he described a sandstone which 

 Mr. Daintree identifies with his " Desert Sandstone." He says 

 the specimens from the Victoria River agreed exactly with 

 those from the Desert Sandstone of Queensland, and were 

 undistinguishable one from another, " while the same sandy soil, 

 the same hostile Spinif ex* (Triodia), the same fatal poison plantf 

 mark its presence from Perth to Cape York. In Queensland the 

 upper beds are ferruginous, white and mottled sandy clays, the 

 lower being coarse alternating grits and conglomerates ; the 

 extreme observed thickness has not exceeded 400 feet. A 

 characteristic view of the Upper Desert Sandstone beds is shown 

 in Betts' Creek. 



" Whether these are marine, lacustrine, or estuarine deposits, 

 there is hardly sufficient evidence to show ; the enclosed drift-wood 

 as before observed giving no clue. 



" A single shell (Tellina) found in a bed of horizontal limestone 

 at the head of the Gregory on the Barkly Tableland, and 

 forwarded to me by the Rev. W. B. Clarke, of Sydney, would, if 

 belonging to this series as it probably does, give reason to believe 

 that the lacustrine condition may be eliminated." (Daintree, 

 op. cit., p. 277.) 



It is now ascertained that the limestones on the Barkly 

 Tableland do not belong to the Desert Sandstone formation at all, 

 "but to the great Cretaceous formation of Central Australia. 



In Mr. Daintree's essay a section is given of the upper valley 

 of the Victoria River. This section shows : (1) Desert Sandstone, 

 in massive tableland and flat-top outliers covering (2) basaltic or 

 trap rocks, which sometimes lie above the sandstone through an 



* The species commonly called Spinif ex in Australia, has been confused 

 by some strange mistake with a grass which bears that name, but so 

 entirely different from the Australian desert grass that it is as well to 

 point out what that difference is. The true Spinif ex are spreading or 

 creeping hard branching grasses growing in the loosest sand by the 

 sea-shore only, forming large tufts with dieecious spikelets, the leaves 

 being sometimes smooth and sometimes covered with a silky pubescence. 

 Besides three Australian species which are entirely marine, there is 

 a fourth very closely allied to one of the Australian species, widely spread 

 along the sandy sea-shores of tropical Asia. Triodia on the contrary is 

 entirely a desert prickly grass, with leaves as sharp and as stout almost 

 as needles. There are six species, supposed to be distinct from one 

 another, in Australia, the two commonest being T.pungens and T. irritans. 

 Besides the Australian members of the genus there is a common 

 European Triodia and a few African species. 



f The poison plant is Gastrolobium grandiflorum, F. v. M., not confined 

 unfortunately to the Desert Sandstone. 



