[Footnote 93: The reader will find an excellent account of the Permo-Carboniferous glacial deposits in a paper by Prof. Edgworth David, entitled "Evidences of Glacial Action in Australia in Permo-Carboniferous Time" (_Quart. Journ. Geol. Soc._ Vol. LII. p. 289). In this paper other glacial beds besides those of Australia are noticed.] _The Flora and Fauna._ The flora of the Permo-Carboniferous beds has caused as much discussion as the question concerning the origin of the boulder-deposits. In the southern hemisphere, the Permo-Carboniferous rocks of those countries which have yielded boulder-beds also contain remains of a flora which is now known as the _Glossopteris_ flora, from the prevailing genus, which is associated with other genera, such as _Gangamopteris_. These fossils appear to be ferns, though their modern allies have not been indicated with certainty; associated with them are rare cycads and conifers. The _Glossopteris_ flora is markedly contrasted with the Coal-Measure flora of the northern hemisphere with its giant lycopods. Moreover _Glossopteris_ appears in the northern hemisphere in rocks of later date than the Permo-Carboniferous period. It has been suggested that the _Glossopteris_ flora originated in a continent in the southern hemisphere, on which the boulder beds were also formed in isolated water areas, and that some of the forms migrated northwards. To this continent the name Gondwanaland has been applied by Prof. Suess, from the _Gondwana_ series of the Permo-Carboniferous rocks of India, in which the _Glossopteris_ flora is found, and it has also been maintained that the southern _Glossopteris_ flora was contemporaneous with the northern flora of ordinary Coal-measure type, though whether this was so to any extent remains to be proved, for the beds containing the _Glossopteris_ flora are distinctly newer than any which have furnished a typical northern Coal-measure flora. In any case, the change of floras between Coal Measure and Permo-Carboniferous times is very marked, and when taken in connexion with the widespread glacial deposits, is one of the most striking phenomena displayed by the rocks of the stratified column[94]. [Footnote 94: For an account of the Glossopteris flora and its geological relations, consult Seward, A. C., _Science Progress_, January, 1897, p. 178.]