44 
Geology and Physical Geography: 
(Eickwald), var. Australis (McCoy), a ganoid placodermatous 
fish, concerning which Professor McCoy remarks that it is an ex- 
traordinary circumstance to find in Australia these representatives 
of the “ great ganoid armour-plated fishes ” of the genus Astcro - 
lepis, which are amongst the most abundant and striking charac- 
teristics of the Devonian rocks of Russia, “ in limestones of the 
same age, and accompanied by the corals and shells of the Plymouth 
and Eifel limestones of similar age, with which they are not known 
to occur in England or Germany, and which do not occur with 
them in the Russian beds. ,, 
The Bindi limestones constitute a patch low down in the valley, 
and on the east side of the Tambo River, and occupy a basin in 
the older rocks, which here consist of granites, quartz-porphyries, 
and indurated Silurian slates. The Tambo River has eroded its 
course round the northern and western margins of the limestones, 
along their junction with the older rocks, and consequently a 
large portion of the western side of the limestone area has been 
removed. 
The dip of the limestone beds which remain is to the south- 
west, or from their eastern rim. 
The fossils .found in the Bindi limestones arc principally the 
characteristic spirifers, and aro very plentiful. 
The Buchan limestones occur between the Buchan and Murrin- 
dal Rivers, near their junction, and occupy a deep hollow in the 
Snowy River porphyries, into which they have been further lot 
down by faults. The limestones are dark -blue to nearly black, 
compact, and somewhat thickly bedded, and generally dip away 
from the porphyries which encircle them. They also show evi- 
dences of having been subjected to considerable folding and con- 
tortion in places. Numerous sink-holes occur in this limestone 
tract ; in one place the Murrindal River flows into a sink-hole, 
and has for some distance a subterranean passage, re-appearing 
again further down its course. A surface channel exists, but 
water only flows in it during floods, when the quantity is too great 
to escape by the underground passage. 
All the above-mentioned fossils have been found in the Buchan 
limestones. 
Other similar but smaller patches of Middle Devonian lime- 
stone occur — occupying hollows in the Snowy River porphyries — 
in the valley of Basin Creek, eastward from the Murrindal ; in the 
Yalong Creek, near its junction with the Snowy River ; at Gel- 
lingall, at the junction of the Woolslied Creek and the Buchan ; 
at the junction of the Snowy River and the Buchan ; and at 
Butcher’s Ridges, near Gelautipy, where there arc three patches 
occupying hollows in the porphyries — one capped by basalt on the 
table-land, and two other smaller ones on either side of Butcher's 
Creek. 
