Seite - 532 - in The Origin of Species

532 GLOSSARY 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 MoUusca, 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. Branchicc—Gills or organs for respiration in water. Branchial—Pertaining to gills or branchis. Cambrian System—A series of very ancient Palaeozoic rocks, between the Laurentian and the Silurian. Until recently these were regarded as the oldest fossiliferous rocks. Canida—The Dog-family, inc:uding the Dog, Wolf, Fox, Jackal, &c. Carapace—The shell enveloping the anterior part of the body in Crustaceans generally; applied also to the hard shelly pieces of the Cirripedes. Carboiiferous—This term is applied to the great formation which includes, among other rocks, the coal measures. It belongs to the oldest, or Palaeozoic, system of formations. Caudal—Of or belonging to the tail. Cephalopods—^The highest class of the Mollusca, or soft-bodied animals, characterized by having the mouth surrounded by a greater or less number of fleshy arms or tentacles, which, in most living species, are furnished with sucking-cups. {Examples, Cuttle-fish, Nautilus.) Cetacea—An order of Mammalia, inc'uding the Whales, Dolphins, &c., havirjg the form of the body fish-like, the skin naked, and only the forelimbs developed. Chelonia—An order of Reptiles, including the Turtles, Tortoises, &c. Cirnpedes—An order of Crustaceans including the Barnacles and Acorn- shells. Their young resemble those of many other Crustaceans in form; but when mature they are always attached to other objects, either directly or by means of a stalk, and their bodies are enclosed by a calcareous shell composed of several pieces, two of which can open to give issue to a bunch of curled, jointed tentacles, which rep- resent the limbs. Cocc!<5—The genus of Insects including the Cochineal. In these the male is a minute, winged fly, and the female generally a motionless, berry- like mass. Cocoon—A case usually of silky material, in which insects are frequently enveloped during the second or resting stage (pupa) of their existence.The term " cocoon-stage " is here used as equivalent to " pupa-stage." Calospermotis—A term applied to those fruits of the UmbelliferEe which have the seed hollowed on the inner face. Coleoptera—Beetles, an order of Insects, having a biting mouth and the first pair of wings more or less horny, forming sheaths for the second pair, and usually meeting in a straight line down the middle of the back.Lolumn—A peculiar organ in the flowers of Orchids, in which the stamens, style and stigma (or the reproductive parts) are united. Composita- or Compositous Plants—Flants in which the inflorescence con- sists of numerous small flowers (florets) brought together into a dense head, the base of which is enclosed by a common envelope. (Examples the Daisy, Dandelion, &c.) Conferva—^The filamentous weeds of fresh water. Conglomerate—A rock made up of fragments of rock or pebbles, cemented together by some other material. Corolla—rrhe second envelope of a flower, usually composed of coloured,leat-hke organs (petals), which may be unHed by their edges eitherin the basal part or throughout. Correlation—The normal coincidence of one phenomenon, character, &c with another. ' ' Corymh—A bunch of flowers in which those springing from the lower partot the flower stalk are supported on long stalks so as to be nearly ona level with the upper ones. i