Analcime is found in granite and gneiss rock—generally in cubes of various colors.

Ananchytes. A genus of fossil echini or sea-urchins—in the chalk, &c.

Anchylosis. (Gr., crooked), a joint is said to be anchylosed, when so diseased as to become, or when it becomes, stiff or immovable.

Annelidæ. (Annulus, a ring)—Lamarck’s worm-shaped animals, as Serpula, vermilia, &c.

Anoplotherium. The name given to a characteristic genus of a group of extinct quadrupeds found fossil in the older Tertiary deposits, and nearly allied to the tapir and pig.

Anticlinal. Or Anticlinal axis. A saddle-shaped position of rocks, the result of disturbance.

Apiocrinite. Pear-shaped crinoidea—lily-shaped animals.

Aqueous. That which is dependent on water. Aqueous rocks are those produced by deposit from water.

Arborescent. Branching like a tree.

Arenaceous. Sandy.