BY THE REV. W. WOOLLS. 33 



species, comparatively speaking, have left their original source is 

 a problem not yet solved, and it is doubtless the result of causes 

 which remain to be explained in reference to geological periods 

 long past. Whatever may be the cause, it is a fact that in the 

 great orders Leguminosse, Myrtacese and Proteacese, many of the 

 western genera are either wholly unrepresented or only partially 

 represented in the east. For instance, the large genera Gastro- 

 lobium and Jacksonia have very few species out of Western 

 Australia, whilst at least four genera are not represented in any 

 other part of Australia. In the Myrtaceje, also, a similar unequal 

 distribution appears. The large genus Verticordia, with the 

 exception of one species in Queensland and Northern Australia, is 

 exclusively western ; and Calycothrix, with its numerous species, 

 has only two representatives in N. S. Wales. Actinodium, P'de- 

 anthus, Wehlia, Astartea, Hypocalymma, Balaustion, Conothamnus, 

 Regelia, Phymatoc'wpns, Calothamnus, Lamarchea and EremcBa are 

 limited to the west ; and in Eucalyptus not more than six or seven 

 species are common to both regions. Again, in the Proteacese, 

 Simsia, Synaphea, FranUandia, and the large genus Dryandra, 

 no species have migrated eastward ; whilst in Petropldla, Isopogon, 

 and Banksia, the eastern species are few. In the large order of 

 the Compositfe, 206 occur in the west and 296 in N. 8. Wales. 

 Only three genera, with one species each, viz., Pithocarpa, Decazesia 

 and Trichocline, are peculiar to W. Australia. It must be remarked 

 in reference to this order that the species are more widely dis- 

 tributed than any other, being easily conveyed by the nature of 

 their seeds, and being in many instances mere weeds suited to all 

 climates. Notwithstanding these considerations, however, many 

 of the western, species are truly local, whilst the number of the 

 eastern composites has been augmented by plants from Asia, 

 Australasia and Polynesia. In the Epacridese, Oligarrhena, 

 Needhaniia, Conostephium, Coleanthera, Lysinema, Cosmelia, 

 Sphenotoma and the large genus Andersonia, nine of the species 

 occur in the East ; whilst amongst Monocotyledonous plants, all 

 the species of the Hsemodoracese, with the exception of very few, 

 are strictly limited to the west. It would be easy to pursue the 



