118 
as surely as gastropod beds are found, close at hand appears a 
polyzoal rock, as if there was some intimate connection between 
the two. On the whole, the latter is apparently a deeper sea 
deposit than the former, which can only be formed in shallower 
water. If this is the true explanation, a simultaneous deposition 
of the two kinds of strata may have taken place in closely ad- 
joining areas. 
In the above remarks, actual equivalence of geological age for 
the polyzoal rocks of separate localities is not necessarily im- 
plied, but see infra. 
The correctness of our reading of the Spring Creck section, as 
given in Part I.,* is amply borne out by further observations 
made within the last few weeks by one of the present writers, in 
company with Mr. J. Mulder and the Rev. A. Cresswell. 
At the south end of the section it will be remembered that the 
rugged Polyzoal rock passes gradually into slightly softer strata 
full of Echinoderms, but showing few other fossils, except an oc- 
casional bivalve. Similar strata, also containing numerous ex- 
amples of Echinoderms, overlie the shell beds on the south side 
of “The Ledge,” but owing to the dip and the increased steep- 
ness of the cliffs the fossils are there out of reach, and are only 
known from the fallen blocks lying upon the beach. From them, 
however, not only Echinoderms, but also mollusca in limited 
numbers have been gathered. 
At a point still more to the south, known as the “ Fishermen’s 
Steps,” from the fact that footholds have been cut in the 
Echinoderm rock, the cliffs are less abrupt and can be scaled 
with ease. Driven by the advancing tide from the usual 
collecting grounds to this locality, a perpendicular rock from 
30 to 40 feet up the cliff was searched for Echinoderms, almost 
the only fossils visible. Overhead, and resting directly upon a 
projecting ledge at the top of this rock, a large quantity of 
broken bivalves showed, looking in the distance like the shells of 
a raised beach. By a little awkward climbing they were reached, 
and proved to be derived from an earthy bank overlying the 
echinoderm rock. Starting from the narrow ledge on the top 
of this rock, where the broken shells have accumulated, the 
fossiliferous earths and clays extend up the cliffs, with here and 
there a narrow band of hard rock alternating with the softer 
material. A somewhat similar alternation of rocky bands and 
clays is observable at the north end of the section, near the Bird 
Rock ; the fossils in the clays there are, however, scarcer, and 
include some species not yet found at the Fishermen’s Steps. 
* Correlation of the Marine Tertiaries of Australia. Roy. Soc, of South 
Australia, vol. XVII., pp. 206 ef seq. 
