64 
THE GEOLOaiST. 
hills are partly granitic ; the granite is reddish, very readily decom- 
posed, and worn by the rain and weather here and there into strange 
grotesque figures. * There are well- defined metallic lodes in this range. 
East of these hills are three terraces leading down to the river. 
The first is the broadest, extending about two-thirds the distance, 
and falls twenty feet to the river. It is composed chiefly of sand ; 
but rocks similar to those of the western rock crop out here and 
there. The second terrace averages about two-ninths of the distance 
between the range and the river : it falls about thirty feet ; some- 
times not more than ten or fifteen feet ; at places, however, more than 
fifty feet. The third or lowest terrace is only one-ninth of the dis- 
tance, and nearly level with the river : in fact, it is overflowed when 
the water is up. The river itself flows slowly, having a fall of about 
one foot a mile. It is at the fall or escarpment between the second 
and the third terrace, on an exposed face of friable limestone, that 
the peculiar substance referred to in this notice is found. The 
whitish limestone (similar to the bryozoal limestone of the Mount 
Gambier district) has its exposed edges excavated by innumerable 
be the concreted exhalations and eflB.uvia coming from the heated in- 
teriors of these long-inhabited and thickly tenanted burrows. The 
concretion is thickest just within and at tl\e mouth of a burrow, and 
dies away upwards on the face of the rock, just as the stain of smoke 
coming from a crevice is dark at the fissure, and becomes fainter and 
fainter up the side of the wall. This material is several inches thick, 
and, owing to the dryness of the climate, is not washed away by rain. 
In England the specimens brought over are somewhat deliquescent. 
It has not yet been examined chemically. 
This curious concomitant of cave-habitats in a warm and dry cli- 
mate seems worth notice as connected with the subject of *bone-caves. 
The same country (South Australia) is likely to afford valuable in- 
formation relative to the origin and early condition of subterranean 
caves and fissures ; for the limestone of the Mount Gambier district 
is extensively excavated by subterranean drainage, on which the 
water-supply of the towns and stations is, to a large extent, depen- 
dent. 
The samples of brown material referred to in the above remarks were 
obtained from a place on the Elver Murray, near the Eeedy Creek 
(Toongell) or the Thirty-nine Sections, called Pontarra, or Green 
AA Wallabies' Holes. 
Fig. 2. 
Eiver Murray. 
burrows of wallabies, 
kangaroo - rats, opos- 
sums, etc., which live 
and breed here in count- 
less numbers, far in the 
body of the rock, and 
the upper part of the 
openings of these bur- 
rows are coated with a 
softish-brown fetid ma- 
terial, which appears to 
