BY R. M. JOHNSTON, F.L.S. 141 
Paleozoic rocks; those most apparent being of Upper 
Silurian Age, and in the Eldon Valley, Princess River, 
consisting largely of clay slates, mudstones, and schistose, 
sandstones with thin quartz reefs, and in certain beds, richly 
fossiliferous, the-following forms are especially prolific :— 
Calymene, Pentamerus, Orthis, Strophomena, WSpirifera, 
Atrypa, Lingula, Rhynchonella, Leptaena, Loxonema, Favosites, 
encrinital stems, etc. Unconformably lying upon these we 
have in succession, as on Eldon Peak, Camp Hill, Rocky 
Hill, etc., in ascending order :— 
I. Upper Paleozoic grits, conglomerates, and mudstones, 
with the usual abundance of winged spirifers 
Productus, Terebratula, Strophalosia, Aviculopecten, 
Pachydomus, Sanguinolites, Streblopteria, Avicula, 
Palearca, Tellinomya, Inoceramus, Pterinea, Notomya, 
Platyschisma, Orthonata, Conularia, Goniaites, Steno- 
pora, Protoretepora, Fenestella, Encrinites, ete. 
II, Thick bedded sandstones, shales, and coal, as at Coal 
Hill, Mount Gell, ete., of which no fossil evidence 
has yet been obtained, but which may possibly 
embrace the Lower Coal Measures with Glossop- 
teris, Gangamopteris, and Neggarathiopsis; the 
Lower Sandstones of Mesozoic Age, with Vertebraria 
and ganoid fishes; and the Upper Coal Measures 
Shales and Sandstones, with Zeugophyllites, Baiera, 
Pecopteris, Spenopteris, Thennfeldia, Neuropteris, 
Teniopteris, Salisburia, Pterophyllum, ete. 
III. Massive cap (?) or elevated cores (?) of diabasic 
ereenstones—the most characteristic feature of all 
our mountain peaks, bosses, and plateaux, from 
Mounts Tyndall and Dundas on the west, to St. 
Patrick’s Head and La Perouse on the east. 
IV. Inkerman River, across the spurs of Gould’s 
Pyramid, Alma River, Mount Gell to valley of the 
Dixon and Undine; base—Metamorphic schists 
quartzites, gneiss, conglomerates, etc., with over- 
lying rocks, as on Eldon Peak, at Mount King 
William, Mount Hiigel, and Mount Gell; and on 
intervening ridges and peaks, as Rocky Hill, Gould’s 
Pyramid, and Coal Hill, the usual sandstone shales, 
grit, etc., whose age may be Upper Paleozoic or 
Mesozoic, or include both; but in the absence of 
paleontological data, cannot now be determined. 
Apart from the Brachiopod sandstones, Clay-shales, 
Hydromica-schists, and more recent conglomerates further 
west, between Mount Lyell and the Tertiary Lignites and 
Leaf Beds of Macquarie Harbour, this region affords a grand 
