Good collections of shells of the Balcombian series may be easily made at Balcombe's Bay and Grice's Creek, Port Phillip. They can there be dug out of the grey-blue clay with a knife, and afterwards cleaned at leisure by means of a soft tooth brush dipped in water. In the cement stone at the same place there are numerous shells of pteropods or "sea-butterflies" (_Vaginella_), and specimens of the stone may be obtained, showing myriads of the porcelain-like shells, and also their internal casts in the hard greenish coloured matrix. The ferruginous or ironstone beds seen in the Flemington Railway cutting, Melbourne, is an old marine shell-bank, resting on basalt. The shells have all been dissolved away, and only their casts and moulds remain. These impressions are, however, so faithfully moulded that the ornamentation of each shell can often be reproduced on a squeeze taken with a piece of modelling wax or plasticine. Such fossil remains are easily collected by carefully breaking up the blocks of ironstone with a hammer. Quarries in the older limestones and mudstones in Victoria, New South Wales and other States, are often good hunting grounds for fossils. The quarry at Cave Hill, Lilydale, for example, will be found very profitable, for the limestone is full of corals and molluscan shells; whilst the friable or rubbly portion is worth breaking down for the smaller fossils. The bed-rock (Silurian) of Melbourne is in places very fossiliferous; the sandstones of Moonee Ponds Creek generally affording a fair number of brachiopods, and occasionally corals. The mudstones of South Yarra, Studley Park, Yan Yean, and other places on the same geological horizon, contain a rich fauna, to be obtained only by the assiduous collector who will search over and break up a large number of blocks. Practice in this work makes a good collector; although of course one must know something about the objects looked for, since many apparently obscure fossil remains of great interest might easily be passed over for lack of knowledge as to what should be expected to occur at each particular locality. Many other good collecting grounds might here be alluded to, but we have purposely cited only a few near Melbourne, since a selection from other parts of Australasia may easily be made from the localities mentioned in connection with the various groups of fossils dealt with in the systematic portion of this work. =Preservation of Fossils.--=