ASYMMETRICAL.—Having the two sides unlike.
ATROPHIED.—Arrested in development at a very early stage.
BALANUS.—The genus including the common Acorn-shells which live in abundance on the rocks of the sea-coast.
BATRACHIANS.—A class of animals allied to the Reptiles, but undergoing a peculiar metamorphosis, in which the young animal is generally aquatic and breathes by gills. (Examples, Frogs, Toads, and Newts.)
BOULDERS.—Large transported blocks of stone generally embedded in clays or gravels.
BRACHIOPODA.—A class of marine Mollusca, or soft-bodied animals, furnished with a bivalve shell, attached to submarine objects by a stalk which passes through an aperture in one of the valves, and furnished with fringed arms, by the action of which food is carried to the mouth.
BRANCHIÆ.—Gills or organs for respiration in water.
BRANCHIAL.—Pertaining to gills or branchiæ.
CAMBRIAN SYSTEM.—A series of very ancient Palæozoic rocks, between the Laurentian and the Silurian. Until recently these were regarded as the oldest fossiliferous rocks.
CANIDÆ.—The Dog-family, including the Dog, Wolf, Fox, Jackal, &c.