In the upper beds of the Silurian, those of the Helderberg series, we still find _Psilophyton_ and _Nematophyton_; but below these we know no land-plants in Canada. In the United States, Lesquereux and Claypole have described remains which may indicate the existence of lycopodiaceous and annularian types as far back as the beginning of the Upper Silurian, or even as low as the Hudson River group, and Hicks has found _Nematophyton_ and _Psilophyton_ in beds about as old in Wales, along with the uncertain stems named _Berwynia_. In the Lower Silurian the _Protannularia_ of the Skiddaw series in England may represent a land-plant, but this is uncertain, and no similar species has been found in Canada. The Cambrian rocks are so far barren of land-plants; the so-called _Eophyton_ being evidently nothing but markings, probably produced by crustaceans and other aquatic animals. In the still older Laurentian the abundant beds of graphite probably indicate the existence of plants, but whether aquatic or terrestrial it is impossible to decide at present. It would thus appear that our certain knowledge of land-vegetation begins with the Upper Silurian or the Silurio-Cambrian, and that its earliest forms were Acrogens allied to Lycopods, and prototypal trees, forerunners of the Acrogens or the gymnosperms. In the Lower Devonian little advance is made. In the Middle Devonian this meagre flora had been replaced by one rivalling that of the Carboniferous, and including pines, tree-ferns, and arboreal forms of Lycopods and of equisetaceous plants, as well as numerous herbaceous plants. At the close of the Erian the flora again became meagre, and continued so in the Lower Carboniferous. It again became rich and varied in the Middle Carboniferous, to decay in the succeeding Permian. II.--HEER'S LATEST RESULTS IN THE GREENLAND FLORA. A very valuable report of Prof. Steenstrup, published in Copenhagen in 1883, the year in which Heer died, contains the results of his last work on the Greenland plants, and is so important that a summary of its contents will be interesting to all students of fossil botany or of the vicissitudes of climate which the earth has undergone.[FQ] [FQ] Meddelelser om Gronland, Hefte V., Copenhagen, 1883. The plant-bearing beds of Greenland are as follows, in ascending order: 1. Cretaceous. 1. The _Komé_ series, of black shales resting on the Laurentian gneiss. These beds are found at various other localities, but the name above given is that by which they are generally known. Their flora is limited to ferns, cycads, conifers, and a few endogens, with only _Populus primæva_ to represent the dicotyledons. These beds are regarded as Lower Cretaceous (Urgonian), but the animal fossils would seem to give them a rather higher position. They may be regarded as equivalent to the Kootanie and Queen Charlotte beds in Canada, and the Potomac series in Virginia.