136 
MAGAZINE OF SCIENCE AND ART. 
and otliers in the neighbourhood, Mr. William 
Hardy, whose -zeal as a collector is well known, 
made a fine collection of fossils, which he was good 
enough to place at my disposal, and these have as¬ 
sisted materially in establishing the fact that the 
upper Silurian formation is well developed there. 
My own explorations and researches, during many 
years, in various parts of the colony, have also ena¬ 
bled me to discover many new genera and species, 
as well as some already known, which have been, 
after cotnparisonby Mr. Salter, and other geologists 
in Europe, referred, without hesitation, to the, 
Silurian epoch. Mention of these discoveries is 
made in Murchison's Siluria; and some of the fossils 
of this epoch from Australia were included by me 
in the selection which I exhibited at Sydney in 
1854, and in Paris in 185-5. 
Mr. Hero W. Nichols, of Bulanamang, also sent 
me fossils of the same age from the neighbourhood 
of Queanbeyan some years ago, and subsequently 
from Maneroo, in which district I explored numer¬ 
ous localities rich in Silurian fossils. Of my various 
collections from the districts already mentioned, 
and others in the New England district, I sent 
home a large series to the Woodwardian Museum, 
in the University of Cambridge, in addition to the 
rocks and fossils of the Carboniferous formation 
which 1 had previously forwarded. The fossils from 
Yarralumla are hereafter to be described and illus¬ 
trated by Mr. Salter. I can speak of that, as a most 
fertile and interesting locality; it has already sup¬ 
plied me with Trilobites, of the genera Calymene; 
Phacops; Encrimirus; Cerauras and Harpes, toge¬ 
ther with a numerous array of Corals and Molluscs, 
&o., some of which I have found also common at 
the Shoalhaven gullies ; on the Deleget river ; at 
Quedong; Rock-flat, near Coonta; near Tam- 
worth, on the Peel river; in the western country, 
and in other localities. 
Mr. Stuchburv, also, sent down many fossils of 
the same epoch from the Beil river and its neigh¬ 
bourhood; and in Victoria. Mr. Sclwyn, the distin¬ 
guished geologist, now employed hv the government 
of that colony, has discovered abundant accumula¬ 
tions, which are under the examination of that 
accomplished Palaeontologist, Professor M'Coy. 
I had the satisfaction of a day’s exploration with 
Mr. Selwyn, at one of his camps, in the neighbour¬ 
hood of Melbourne, and had ocular evidence of the 
existence of the Silurian formations in that neigh¬ 
bourhood. Moreover, when I was at Hobarton in 
1856, my friend Dr. Milligan exhibited to me 
fossils from the Franklin river, in Tasmania, nearly 
identical with species I had collected abundantly 
in this colony. I had also, in 1S*51, found Silurian 
fossils not far from the head of one oi the upper 
branches of the river Murray, within the Victoria 
border of the Alps. I am, therefore, justified in 
stating, that it has now been long known, that be¬ 
low our Carboniferous formation, there are well- 
developed strata of true Silurian age, which appear 
to repose against rocks of igneous character, parti¬ 
ally of an older epoch, though the whole of these 
formations in this Colony, in Victoria, and in 
Tasmania, have been dislocated, and transmuted, 
and overflowed, in numerous localities, by igneous 
outbursts of a comparatively recent epoch. 
It is, however, a singular fact; that although I 
have found in this colony numerous corals and 
other ancient fossils, agreeing in minute particulars 
witli species figured in “ Siluria.’ Ac. I havenever 
been able to detect a single species of *• (irapiditt- 
and it was not till late in 1856, that the geological 
surveyor in Victoria had made the discovery there. 
This should be an inducement to collectors in this 
colony to be on the look out'for that characteristic 
genus, and others akin to it, ivnich, I have no doubt, 
will be found here, as in all other Silurian regions. 
The specimens of rocks sent by Mr. Robertson 
are such as characterise the Silurian beds in New 
South Wales. In his neighhourhood, as elsewhere, 
the upper Silurian formation is made up of brownish 
or greyish and greenish mud-stones; light coloured 
and often white limestones (transmuted to saccha¬ 
rine marble); whitish grits and sandstones; with 
soft silky schists (nearly slates) of grey and light 
tints, and coarser brown schists, banded by veins 
and ribs of quartz (which are auriferous) and of 
these the mud-stones, which are much charged with 
yellow ferruginous powder, contain the greater 
part of the fossils, though occasionally the lime¬ 
stones, as on the Molong, the Mummibidgee, and 
Deleget rivers, and on the Shoalhaven and Bell, 
are foil of corals, which are exposed naturally on 
the weathering oi the rock. These rocks, placed 
in parrailel juxta-position, are highly inclined, 
along a merid'ian line of striae. 
The Carboniferous formation about Yass, and to 
the eastward along the Dividing ranges, has been 
greatly, and in numerous localities, entirely de¬ 
stroyed, and the only relics are frequently pieces of 
siliciiied wood, which occur on the plains and the 
slopes of the hills. A specimen of this is included 
in the collection under notice. The rock speci¬ 
mens are white marble ; dove-coloured limestone ; 
white sandstone; and greenish mudstone. 
The genera of fossils contained in the latter, are 
all that°ean he ascertained, as they are only casts 
closely congregated, and too imperfect to distin¬ 
guish as species. The genera are as follow 
Ithynconella. Orthis. Hemithyris. 
Lcptena. Atrypa. 
Mr. Robertson mentions Terebratula, Tentacu- 
lites, and Pentcmerus. The former genus is now 
discarded from lists of Silurian fossils, as no true 
Terebratula exists in the formation. Tentaeulites 
and Pentamerus I have found to the southward of 
Duntroou, and the latter genus on the Shoalhaven; 
but they are not included in the present collection. 
The other fossils consist of casts of a beautiful 
minute Petraia (with 30 lamella;); fragments of 
Crinoidal remains; the pugidium of a tnlobite 
allied to Encrinurus, but near Cronins of Barrande; 
and a portion of the glabella ot an Encrinurus. 
The Silurian collection which 1 lately arranged 
in the Australian Museum contains Encrinurus, 
Harpes, and a fine Calymene Blumanbachii, with 
another Crustacean, a Beyriehia, all of which are 
from Yarralumla. It is not necessary to mention 
here other genera and species in mv own collection. 
As I am very much interested in the develop¬ 
ment of the Silurian formations in Australia, I shall 
be thankful if collectors will be good enough 
to forward tome for examination and use any fossils 
thev may meet with. Even if they happen to send 
me what I already have, they will he doing good 
service, because it is almost impossible to ascertain 
species, unless one can destroy several specimens 
in the comparison of the distinguishing character¬ 
istics. . , , 
I take the liberty of requesting this at the hands 
of geological collectors in the colony. 
St. Leonard’s, M . B. CLARKE. 
12lh Oct., .1857- 
