GLOSSARY. The law authorizing the present geological survey provides that a glossary shall accompany each volume of reports. Allurial-That which is deposited by the washing of rivers along their course. Amplexus- A genus of fossil corals. Anticlinal — A given line or ridge from which the strata dip in both directions. Arenaceous-Sandy, containing sand. Argillaceous Clayey, containing clay. Block-locust-Robinia pseudoacacia. Bluff - deposit - The formation composing the Missouri river bluffs. See article on "Lakes of Iowa, past and present." Beyrichia A genus of minute fossils belonging to the same order with crabs and lobsters. Borers - The larvæ of an insect that deposits its eggs upon the bark of the black - locust. When the larvæ are hatched they bore their way into the body of the tree in such numbers as to destroy it Bottom-A Western term, applied to the low, flat, alluvial lands so common along western rivers. Coal - measures -- A name for that assemblage of carboniferous strata which contains the coal. Conglomerate-Gravel and sand consolidated into rock. Cottonwood-Populus monilifera. Cranberry-common -Vaccinium macrocarpum. Cranberry-high-bush - Viburnum oxyccccus. Crania - A genus of fossil shells. Cretaceous - The name of a geological age. The chalk of Europe belongs to the cretaceous age. Crustacean-Belonging to one of the animal sub-kingdoms. It embraces insects, lobsters, crabs, starfishes, &c. Cryptacanthia-A genus of fossil shells. Cryptoceras-A genus of fossil shells. Cythere A genus of minute fossils, related to Beyrichia. - Drift-The formation which contains the boulders. Drifting - Digging a way horizontally into, or within a mine. Fauna - A term used in geology to signify the aggregate of all the animal remains. Ferruginous-Containing iron. Fault-A break in the continuity of strata by the lifting or settling of one part of them. Geodes - Hollow, concretionary, stony masses, usually lined with crystals. Grit Coarse sandstone. Habitat - The naturally chosen place of habitation or growth of an animal or plant. Hydreionocrinus - A genus of fossils belonging to the same order with starfishes. Marlite Limy clays, usually in indistinct layers; common among the coal measure strata. Meekella- A genus of fossil shells. Micaceous - Containing mica. Nautilus - A genus of shells, both fossil and recent. Protozoan belonging to the lowest branch of the animal kingdom. Pinna A genus of fossil shells. Shaft- A perpendicular way into a mine. Sphagnum-A genus of mosses, several species of which usually grow profusely upon peat - marshes. Stratum (plural, strata) — layers, or beds of rocks. Synclinal- A given line or longitudinal depression, toward which the strata dip in both directions. Timber - A term applied in the West to all native groves or bodies of forest trees. Tomoceras-A genus of fossil shells. |