324 Cc. F. LASERON. 
(a) Freshwater Series.—A good section of these is 
exposed in the mountain side near the junction of Yalwal 
Creek and the Shoalhaven. It consists of three or four 
terraces outcropping in a small dry gully. The thickness 
of the series which consist of finely laminated, micaceous 
shales and sandstones, is here about 30 feet. They rest 
immediately on the Devonian, and their position is generally 
indicated by talus slopes. Nearly all the lamine yield 
fragments of plants, and about midway in the series several 
specimens of Glossopteris and Phyllotheca were obtained. 
Their southern extent can be traced along Yalwal Creek 
for about half a mile, but they narrow down considerably, 
until at last we find the Upper Marine Series resting upon 
the Devonian. 
Near this spot a narrow bed of shale was found about 
eight inches thick interstratified between two thick beds 
of very coarse conglomerate. This also contained frag- 
mentary plant remains. The most western outcrop was 
seen on the Shoalhaven River about three-quarters of a 
mile beyond Yalwal Creek. ‘To the east of the first outcrop 
the shales were not found, except immediately on the 
opposite side of Yalwal Creek. The talus slope is there 
however, but the sandstone gradually encroaching at last 
rests directly on Devonian rhyolites, about a mile from 
Yalwal Creek. 
On the eastern side of Yalwal Creek immediately above 
the Devonian, the freshwater beds are mostly hidden by 
talus slopes, which are very steep and are covered by coarse 
grits and conglomerates. In the conglomerate, however, 
at several different horizons, thin beds of shale occur. Some 
of the layers are very carbonaceous and contain numerous 
fine impressions of Glossopteris, Gangamopteris, Noegger- 
athiopsis and Phyllotheca. These thin seams are lenticular 
and can be traced until no thicker than a sheet of paper. 
