IX-On a flora, including vascular land plants, associated with Monograptus , in rocks of Silurian age, from Victoria, Australia

Abstract

The earliest vascular or land-plants yet known with certainty from the northern hemisphere are those met with in the Lower Devonian or Lower Old Red Sandstone. The few records from earlier rocks have all been open to doubt, either because the age of the beds was not proved or because the plant-remains were obscure. The object of this paper is to describe some well-preserved plants of Silurian age from Victoria, Australia. Since certainty as to the geological age is essential, the present account is limited to the plants collected in four localities, in all of which they were associated with specimens of Mongraptus , the graptolites being found in the same beds and often on the same slabs of rock as the plants, figs. 51-53, Plate 32. The four localities will be referred to under the following names : (1) Yarra Track.—A quarry for road material on the Yarra track between Wood’s Point and Warburton, about 17 miles from the former place. (2) Alexandra.—Two exposures in mudstone (Geol. Survey, loc. 5 and loc. 9), both by the side of the railway line, near the town of Alexandra. (3) Killingworth Road.—Two exposures (Geol. Survey, loc. 14 and loc. 20) at Yea. (4) Thomson River,—This includes a number of exposures along the valley of the Thomson River, where black beds containing Monograptus have long been known in the Jordan River beds (Baragwanath, 1925). This is the locality in which the stratigraphical succession is described (Skeats, 1928).