cclvi 
APPENDIX. 
also to exist here in the shape of a conglomerate. Some specimens from 
Table-hill and its neighbourhood, as also from Liddon’s Gulf, are marked 
with the impressions of bivalves, particularly of a small, flat, ovate cuneiform 
species of Avicula, of which a figure will be given elsewhere under the 
name of A. Melvilliana. 
One of the fragments of compact brown ironstone exhibits a glossy 
surface and fracture, approaching to fibrous. 
There are also specimens of sandstone which exhibit a transition into a 
kind of brown ironstone : in this state it is generally seen as tabular pieces, 
similar to that which in some parts of Norway, fyc., is deposited in beds of a 
few inches’ thickness in sandstone, into which it passes. 
In the same manner the hydrous oxyde of iron is seen to penetrate clay 
which here and there slightly effervesces with acids, and is therefore a ferru- 
ginous marl. 
There are a few varieties of slate-clay, such as might be expected to occur 
with coal and sand-stone formations : they are very soft, of ash-grey, and 
greenish-grey colour, and were found overlaid by sandstone at the bottom 
of ravines. 
The limestone from Melville Island, especially that from Table-hill, bears 
the character belonging to that of the oldest fletz or transition formation. 
The secondary fossils which it contains are chiefly bivalve shells and coral- 
lines. None of these, however, are perfect enough to admit of the deter- 
mination of the genera to which they respectively belong, except a small 
species of Terebratula of that division which comprehends the Petunculi of 
earlier writers on petrifactions, and a species of Favosites, which does not 
appear to differ from F. Gothlandicus. 
There are a few specimens among those from Winter Harbour and Table- 
liill, which appear to bespeak the presence of fletz trap-rocks in Melville 
Island ; but being found as rolled stones, they do not allow any judgment 
being formed of the relation in which they stand to the other formations. I 
have seen from those parts a few small fragments of calcedony, with opaque 
