New South Wales. 
111 
distinct periods of existence. The Dipnoi offer the most remark¬ 
able example of persistence of organization, not ill fislics 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 ot the 
Atlantic and Pacific by the Central American . Isthmus. In 
Ceratodus we have now found a genus which, as far as evidence 
<roes, persisted unchanged from the Mesozoic era ; and in the 
‘sirenidec, & family the nearest ally of which lived in the Palaeo¬ 
zoic 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 general notice in this Memoir has been taken by me ot 
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 (Itydro-igneous rather), and 
tlicir transmutation through such and allied agencies has left 
an impress upon all the rocks more or less concerned. Such 
references will be left to another occasion. 
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 Vales, at least, 
shows little or no visible trace. 
In order to explain the position of Glossopteris in the Paleo¬ 
zoic Marine deposits, I have appended two vertical sections, one, 
by myself, previously published in the “ Transact ions of the 
Itoyul Society of Victoria 1801, 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 Plctcher, Colliery A iewer, 
to whom 1 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 ot the 
Hunter River. No. 2 is about 10 miles west of No. 1. 
1 have also appended two sections, one from Mount A ictonaand 
the other from Burragorang, as well as a map showing portion 
of the AVumamatta Basin—which were made to illustrate my 
paper on “ Oil-bearing Deposits” cited at p. GS, but which were 
not then published. 
