The Sandstones. 
103 
for science to find the Trigonia still surviving in 
Australian seas. There are only about five species 
living to-day, and even these are not too plentiful. In 
the Secondary period, however, they must have been 
extremely abundant, and they swarmed in Oolitic 
seas. 
“Quite recently another link connecting the 
present fauna of Australia with that of Secondary 
Europe has been discovered. Fora considerable time 
a peculiar group of herrings (Diplomystus) charac- 
terised by having a row of scutes on the back, 
resembling those found in other types on the opposite 
aspect of the body, have been known from Cretaceous 
and early Tertiary rocks, their range including Brazil, 
Wyoming, the Isle of Wight, and the Lebanan. Till 
the other day these dou,bly-armoured herrings were 
considered to be totally extinct, but now, lo and 
behold! they have turned up alive in certain rivers 
of New South Wales /’ 1 
The Sandstones. 
It would be superfluous on the writer’s part to. 
describe the Sandstones, when excellent descriptions 
have already been given by Darwin, Clarke, and 
Wilkinson. The last-named author writes : — 
“In the picturesque cliffs around Sydney Harbour, 
and especially in those facing the ocean for some 
miles to the north and south of the Heads, may bo 
1 Lydekker, Life and Rock, p. 161. 
