OF THE INTERIOR OF WESTERN AUSTRALIA. 231 
several smaller areas ; but the only ones having special interest 
for us here are a northern and a central, the dividing line be- 
tween which runs through Charlotte Waters (lat. 26° 81 In 
his Report on the Work of the Horn Scientific Expedition to 
Central Australia, Professor Tate proposes to shift this last- 
mentioned line to the latitude of Engoordina. To the north of 
this lies the Larapintine region; it extends to the Maedonnel 
ranges, close to the Tropic of Capricorn. The central Eremian 
region has for its dominant feature the prevalence of Salsolaceous 
plants; these are replaced in the Larapintine by grasses, of which 
order the “ spinifex” is a characteristic member. Species repre- 
sentative of the Larapintine flora's arboreous vegetation are 
Brachychiton Gregorii (Sterculia diversifolia), Eucalyptus (ter- 
minalis and Oldfieldii), Canthium latifolium, Grevillea striata, 
Ficus platypoda, Casuarina Decaisneana, Livistona Marie, 
Encephalartos Macdonnelli, &e.; while Cassia phyllodinea and 
Eucalyptus rostrata here respectively replace C. eremophila and 
E. microtheca of the central region. How far the West Aus- 
tralian desert flora agrees with that of the neighbouring Colony 
it is impossible to say in the present state of our knowledge. 
Several scientific expeditions have penetrated the solitudes of 
South Australia from south to north almost to the Tropic of 
Capricorn; but hitherto travellers in the West Australian 
desert have moved either east or west or approximately so. The 
most northerly point reached by us was, as near as possible, in 
27°5 lat.; so that, supposing the floristic boundaries to run 
roughly east and west, we did not arrive within the Larapintine 
region at all. The bulk of the plants brought down by me are 
therefore central Eremianand not Larapintine; but some approach 
to the Larapintine flora is announced by the presence, in the 
northern parts of the district visited by me, of the “ spinifex ” 
plains already alluded to, although the occasional abundance of 
* salt-bush " there shows that we were still within the central 
Eremian boundary. I have, however, found records of several 
Larapintine plants which pass over into northern portions of the 
West Australian desert, and of these a list will presently be 
given. 
My sources of information are the following :— 
1. Mr. Bentham’s * Flora Australiensis.’ 
2. Baron von Mueller’s lists of plants collected by Mr. Ernest 
Giles (Journ. Bot. xv. 1877). 
