The accompanying geological map of Queensland (Pl. IX.) may be accepted as giving the approximate areas and rough outlines of the geological structure and rock-systems developed in that Colony, and is appended for that purpose only. It will necessarily be open to criticism in matters of detail; but the general features of the geological grouping may be relied on. The section (Fig. l) from Townsville to the Mackinlay range shows all the geological formations in Queensland, north of 20° S. lat. In a newly settled Colony the first object of the geologist is the determination of those districts in which the best land or available mineral wealth is to be obtained, accuracy in detail and purely scientific investigation being deferred to an often remote future. Fig. 1.–Sketch section from Townsville to the McKinlay Range. (See line on Map.) I collected the following data whilst prosecuting the search for new gold-fields, on behalf of the Queensland Government, in the northern portion of their territory, as also from the official reports of the Geologist of Southern Queensland, and other trustworthy sources. The consideration and history of the different; formations will be taken in their sequence of time, as far as the stratified or sedimentary rocks are concerned. The igneous rocks will be described under the various groups of Granitic, Trappean, and Volcanic. Alluvial. Fluviatile or freshwater deposits skirt all the present water-courses; but the accumulations are insignificant on the eastern water-shed, except near the embouchures of large rivers, such as the Burdekin