118 HORN EXPEDITION — BOTANY. 



with extensive intermediate low-level areas covered with loose detritus. Now, as 

 the result of personal knowledge of the country, I propose to shift the boundary to 

 the latitude of Engoordina, which will accord better with physiographic and 

 botanic contrasts. 



To the north uf this latitude the prevailing feature is a table-land of Ordovician 

 sandstone of an average elevation of 2500 feet, which rises from a base of about 

 1000 feet, gradually increasing to the northward to about 2000 or more feet. This 

 table-land is eroded in long parallel east and west valleys of varying width, from 

 a few chains to sevei'al miles, whilst the river chaianels break through the inter- 

 vening tabular ridges here and there to connect one valley with another in deep 

 narrow precipitous gorges. This is the area which I name Larapintine, from the 

 native name, Larapinta, of the upper and middle Finke River. 



On structural and botanical grounds I extend the region to include the 

 southern watersheds of the Levi and George Gill Ranges, and the northern and 

 western diainages which originate from the western extremity of the Mereenie 

 Escarpment and its westerly extensions. This regiun is bounded un the south-east 

 by reuniants of the Cretaceous table-land, and further west by the depressed area 

 centering in Lake Amadeus ; on the north the Larapintine table-land abuts on and 

 partially enters into the conformation of the McDonnell Range {sensu stricio, as 

 deliminated by Stuart), which forms the southern boundary to the elevated plain 

 called Burt Plain. The route traversed by the main body of the Expedition 

 practically circumscribed the Larapintine region. To the eastward of the meridian 

 of Alice Springs the characteristics of the Larapintine basin are nmch modified by 

 more extensive erosion and change in rock-structure, which, in conjunction with 

 greater aridity, produce a flora much less varied than that of the western section. 



2. Botanical Charactehistics. 



{a) Introduction. — The notions of the generality of people as to the physio- 

 graphy and geology of this region of Central Australia prove to be vague in the 

 extreme. What I had gathered from books and personal statements led me to 

 give such play to my imagination that I had pictured a vast mountain system 

 capable of preserving some remnants of that pristine flora which existed on this 

 continent in Paleocene times — probably a Ijeech, possibly an oak, elm, or sycamore. 

 It was because of such considerations that 1 drew attention in my Inaugural 

 Address at the Adelaide meeting of the Australasian Association for the Advance- 

 ment of Science, 1893, to the desirability of a systematic exploration of the oasis 

 of the 3IcDonnell Range. The awakening came suddenly and rudely, as there 



