L * An independent anatomical investigation of the Mollusca had been carried on by the remarkable Neapolitan naturalist Poli (1791), whose researches 2 were not published until after his death (1817), and were followed by the beautiful works of another Neapolitan zoologist, the illustrious Delle Chiaje.3 The embranchement or sub-kingdom Mollusca, as defined by Cuvier, included the following classes of shellfish: (1) the cuttles or poulps, under the name Cephalopoda; (2) the snails, whelks and slugs, both terrestrial and marine, under the name Gastropoda; (3) the sea-butterflies or winged-snails, under the name Pteropoda; (4) the clams, mussels and oysters, under the name Acephala; (5) the lamp-shells, under the name Brachiopoda; (6) the seasquirts or ascidians, under the name Nuda; and (7) the barnacles and sea-acorns, under the name Cirrhopoda.
Vaughan Thompson, Zoological Researches (Cork, 1830); memoir iv., " On the Cirripedes or Barnacles, demonstrating their deceptive character."
Sometimes the one partner affords the other merely a convenient means of transport, as in the case of the barnacles which grow on, or of the gulf-weed crab which clings to, the carapace of marine turtles.
The barnacles and their allies, forming the group Cirripedia or Thyrostraca, sometimes treated as a separate sub-class, are distinguished by being sessile in the adult state, the larval antennules serving as organs of attachment, and the antennae being lost.
Originally, the name was given to the stalked barnacles (Lepadidae of C. Darwin), which attach themselves in great numbers to drift-wood and other objects floating in the sea and are one of the chief agents in the fouling of ships' bottoms during long voyages.
Acasta sulcata, Lamk., in the scientific study of zoology had replaced the fabulous tales of medieval writers, it was a long time before the true affinities of the barnacles were appreciated, and they were at first classed with the Mollusca, some of which they closely resemble in external appearance.
For a systematic account of the barnacles and their allies, see the article THYROSTRACA.
THYROSTRACA, an order of Crustacea, comprising barnacles, acorn shells and some allied degenerate parasites.
Xxiv., p. 55) added a new species to Plumulites (Barrande, 1872), remarking that the species in question, P. devonicus, " is interesting in being the first representative of fossil barnacles from the Devonian, Barrande's species of Plumulites and Anatifopsis, as well as the Turrilepis of Woodward, being from the Upper and Lower Silurian, and Plumulites jamesi (Hall and Whitf., Pal.
The horizontal distribution of barnacles over all seas is fully explained by Darwin.
Buds of a particular tree growing near the sea were described as producing barnacles, and these, falling into the water, were supposed to develop into geese.
The whole story was an imaginary embroidery of the facts that barnacles attach themselves to submerged timber and that a species of goose is known as the bernicle goose.
Iron ships' plates have recently been coated with copper in sections (to prevent the adhesion of barnacles), by building up a temporary trough against the side of the ship, making the thoroughly cleansed plate act both as cathode and as one side of the trough.
They are ridges of aeolian limestone plastered over by a thin layer of corals and other calcareous organisms. The very remarkable "serpuline atolls" are covered by a solid crust made of the convoluted tubes of serpulae and Vermetus, together with barnacles, mussels, nullipores, corallines and some true incrusting corals.
In some variants of the story this shell is said to grow as a kind of mushroom on rotting timber in the sea, and is obviously one of the barnacles of the genus Lepas.
CRUSTACEA, a very large division of the animal kingdom, comprising the familiar crabs, lobsters, crayfish, shrimps and prawns, the sandhoppers and woodlice, the strangely modified barnacles and the minute water-fleas.
The sheltered waters of the broken southern coast, however, are rich in fish and molluscs, especially in mussels, limpets and barnacles, which are the principal food resource of the nomadic Indian tribes of those regions.
Under Mowat's successors the barnacles which always attach to a party long in power became unpleasantly conspicuous, and in January 1905 the conscience of Ontario sent the conservatives into power, more from disgust at their opponents than from any enthusiasm for themselves.