HR THE VICTORIAN NATURALIST. 
occasionally in other parts, converts extensive tracts of country into 
barren sandy wastes. In the same region, numerous swamps and 
marshes occur, occupying every spot which lies at all below the 
general level. "The difference of level, however, is but slight, as the 
swamps are very shallow, with rare exceptions becoming dry in 
summer. On the rising ground, the sand is covered either by a 
straggling forest of stringy bark and honeysuckle, or by great 
stretches of heath and ferns. It is usually supposed that this vast 
expanse of sand has been left by a retiring sea, but it will be shown 
in subsequent pages, that for the major part of it, this cannot be the 
ease, and a totally different explanation of its origin will be pro- 
posed. In certain portions of Lowan, principally towards the 
Wimmera river, the sand is not quite so abundant as elsewhere, being 
replaced by beds of mud, while the swamps are represented by pools 
of brackish water ; the surface however is still flat, and the landscape 
almost as tame and uninteresting as before. 
The greatest variety of strata is met with in the area enclosed by 
the Glenelg and Wannon rivers, the chief of which are, upper 
palaeozoic in the centre and east, lower palaeozoic in the west, 
granite in the north, with mesozoic, metamorphic, basaltic and trap 
rocks inthe south. Here the scenery is frequently bold and striking, 
and as might be expected among so many distinct formations of a 
diversified character, affording a pleasant contrast with the dreary 
monotony of the sandy plains adjoining. 
After crossing the Wannon, the mesozoic strata continue for a 
short distance, when the miocene and other tertiaries commence, and 
extend in an unbroken series to the sea. Much of this region, how- 
ever, is a basaltic plain, dotted over with numerous conical volcanic 
hills, each with a crater at its summit, from which flowed in recent 
geological times immense sheets of lava, traceable still as winding 
stony rivers for scores of miles over the face of the country. These 
igneous outbursts were the last event in the geological history of 
the province, and their influence in modifying its surface outlines is 
plainly visible. 
The facts given in the succeeding pages may be relied on, as they 
have in every case been recorded from actual personal observation. 
Some of the theories propounded may possibly be challenged, but as 
the only desire is to arrive at the truth, it is hoped that they will 
provoke discussion, and lead in the end to sound views upon the 
geology of this neglected corner of Victoria. I should have preferred 
seeing the subj ect dealt with by abler hands, but in the absence of 
all other obse srvers, I feel bound to do what T can to draw attention 
to such a promising field for geological enquiry. 
It will be most convenient to treat of ie various strata in an 
ascending order, beginning with the lowest, and proceeding upwards 
to the most recent, afterwards taking the eruptive and altered rocks, 
