Pit Coal. Ordinary coal; so called because obtained from pits. Plateau. A plain considerably elevated above the sea. Puddingstone. Coarse conglomerate.

Pacilitic. Variegated; name given in England to a part of the new red sandstone series.

Pyrites.

A compound of sulphur and a metal so called because the chemical changes produce spontaneous heat; it is often mis

taken for gold.

Polythalamous. Many chambered.

Protozoic. Exhibiting first forms of life.

Pryrogenous. Igneous; applied to melted rocks.

Pryroxene. A species of mineral including several varieties, augite, hypersthene, &c. of silicates of lime, magnesia, and iron.

QUADRUMANA. Four handed animals, as the apes.

RAG. A stone of coarse texture.

Rake-vein. A group of vertical veins.

Rubble. A term applied by quarrymen to the fragmentary masses of stone surmounting the beds.

Ruminantia. A group of quadrupeds including those which chew the cud as the ox.

SACCHAROID. Having the texture of loaf sugar.

Saliferous. Salt bearing; the new red sandstone called the saliferous system because it contains salt.

Salses. Eruptions of mud from small orifices in volcanic districts. Savannahs. Low plains in North America, generally covered withwood.

Scaglia. An Italian rock of the cretaceous period.

Scarped. Having a steep face.

Schist. A slate not admitting of such perfect splitting as do the

slates generally.

Seam. A thin bed.

Selenite. Crystallized sulphate of lime.

Silvas. The wooded plains of South America.

Sinter. A rock precipitated from water.

Slickensides. The smooth face of a fault; also one of the Derby

shire lead ores.

Slide. Miners name for a small fault.

Spar. A crystallized mineral which gives a ready fracture.
Stanniferous. Tin bearing.

Stoss. A Swedish term applied to the side of a rock struck or worn by the drift.

Suturbrand. A variety of wood-coal or lignite.

TABLE-LAND. Level land elevated above the seas.

Testacea. Molluscous animals having a shelly covering.

Turbinated. Shells which have a spiral or screw-form structure. Turrilite. An extinct genus of chambered shells, allied to the Ammonite having the siphuncle near the dorsal margin.

UNDERLIE. The inclination of a mineral vein.

WACKE. A German term which has been applied to a soft earthy variety of basalt; it has been used quite indefinitely.

Warp. The deposit from muddy waters artificially introduced into lowlands.

Watershed. The line between two river basins; it is not always a mountain chain.

Whinstone. An English provincial term applied to some trap rocks

ZEOLITE. A family of simple minerals including several varieties usually found in the traps or volcanic rocks; the name is derived from their boiling up when they are exposed to the heat of the blowpipe.