New South Wales . 
61 
of the Dipnoous type, and it is only a proof of the incom¬ 
pleteness of the palaeontological record, that we have to derive 
all our information regarding it from only three so very distinct 
periods of existence. The Dipnoi oiler the most remarkable 
example of persistence of organization, not in fishes only, but in 
vertebrates. On a former occasion I have shown that numerous 
recent species of fishes have survived from the period of the 
geological changes which resulted in the separation of the 
Atlantic and Pacific by the Central American Isthmus. In Cera- 
todus we have now found a genus which, as far as evidence goes, 
persisted unchanged from the Mesozoic era ; and in the Sirenida, 
& family, the nearest ally of which lived in the Palaeozoic epochs.’* 
This is a most valuable link in the connection of the old geologic 
periods with the present era, and a fit conclusion for the account 
above given, however, unworthy that account may be, of Quater¬ 
nary and Recent Accumulations. 
No notice in this Memoir has been taken of igneous rocks ; but 
it may be suitable to state that there is in all the various 
Sedimentary formations noticed distinct evidence of the presence 
of igneous action ( hydro-igneous rather), and their transmutation 
through such and allied agencies has left an impress upon all 
the rocks more or less concerned. 
No particular or special reference could enter into the object 
for which this Memoir is written ; but it is to be understood that, 
though all the rocks have undergone a transmutation, this does 
not constitute what geologists have understood by “Metamorphic” 
system, of which, as before said, New South Wales, at least, 
shows little or no visible trace. 
W.B.C. 
2 June, 1875. 
P.S.—In order to explain the position of Glossopteris in the 
Palaeozoic marine deposits, I have appended two vertical sections, 
one, by myself, previously published in the “ Transactions of the 
Royal Society of Victoria, 18(31,” illustrating the coal seams at 
Stony Creek ; and the other showing the deposits at Greta, near 
Anvil Creek,"which has been reduced from one on a larger scale, 
kindly supplied to me by Mr. James ITetcher, Colliery Viewer, 
to whom I am also indebted for a collection of strata, the charac¬ 
teristics of which I have given after careful examination of them 
and of other specimens collected by myself on former occasions. 
The latter section illustrates a wide area on that part of the 
Hunter River. No. 2 is about 10 miles west of No. 1. 
30th June, 1875. 
Sydney: Thomas Richards, Government Printer.—-187?, 
