bog-moss, in botany; a genus of plants belonging to the class of Cryptogamia and order of Musci. The antheræa are globose; the mouth entire and closed by an operculum; the calyptra is wanting. There are three species, the palustre, alpinum, and arboreum. 1. The palustris, common bog-moss, grows on our bogs in wide patches, so as frequently to cover a large portion of their surface. The stalks are from two inches to two feet long, irregularly surrounded with numerous, conical, pendant branches, and terminated with a rosette of erect short ones. It is generally believed, that the roots and decayed stalks of this moss constitute a principal part of that useful bituminous substance called peat, which is the chief fuel of the northern regions.—The Lapland matrons are well acquainted with this moss. They dry and lay it in their cradle, to supply the place of bed, bolster, and every covering; and, being changed night and morning, it keeps the infant remarkably clean, dry, and warm. It is sufficiently soft of itself; but the tender mother, not satisfied with this, frequently covers the moss with the downy hairs of the rein-deer; and by that means makes a most delicate nest for the young babe. 2. The alpinum, green bog-moss. Its branches are subulate and erect; the antheræa are oval. It grows in mountain bogs in South Britain. 3. The arboreum, creeping bog-moss, is branched; the antheræa are numerous, feathery, hairy, and grow along the branches chiefly on one side. It is found on the trunks of trees.

OS SPHENOIDES, the seventh bone of the cranium or skull. See Anatomy, p. 11.