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Mandibles without feelers, and the mouth always composed of several maxillæ, of which the lower imitate a lip with two feelers. The branchia are commonly seated under the abdomen; all the feet are proper for locomotion or pretension. Onisci.

ORDER V.-BRANCHIOPODA.

Mandibles without feelers; the mouth is sometimes in the form of a beak, sometimes of several maxilla; but the two lower ones have the appearance of a lip with two palpi; feet in form of fins; the branchia are attached to a part between them; the body is generally covered with a shell with which the head is confounded. Monoculi.

CLASS III.-ARACHNIDA.

Head destitute of antennæ ; the external orifices placed under the belly, or the posterior extremity of the breast, lead in some genera to sacs which occupy the place of lungs; in other gencra there exist true trachea, which are distributed to every part of the body.

ORDER I.-PULMONARIA.

Furnished with pulmonary sacs, and six or eight eyes; they have a pair of mandibles, two maxillæ, two feelers, and one lip.

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Pediculus. Pulex.

ORDER II-THYSANURA. Lepismæ.
ORDER III.-PARASITA.
ORDER IV.-SUCTORIA.
ORDER V.-COLEOPTERA.
ORDER VI.-ORTHOPTERA.
ORDER VII.-HEMIPTERA.
ORDER VIII.-NEUROPTERA.
ORDER IX.-HYMENOPTERA.
ORDER X.-LEPIDOPTERA:
ORDER XI.-RHIPIPTERA.
ORDER XII.-DIPTERA.

As the subjects pertaining to this class have been treated at considerable length, in the article ENTOMOLOGY, the ingenuity of the reader it is trusted by drawing supplies of matter thence will com

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Tania.

ORDER II.-PARENCHYMATA.

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Carallina.

Gorgonia.
Isis.
Corallum.

Madrepora.

Alcyonum.
Spongia.

CLASS V.-INFUSORIA.

We have thus given a cursory outline of the leading divisions and sub-divisions of the animal kingdom, unfolded the general principles of classification, and would gladly have dealt out our illustration with a more liberal hand had not our limits withheld us; but it is hoped that the student of this department of science will, from a perusal of this article, derive some important hints towards the method of integrating the gleanings of his daily experience, and of acquiring the habit of generalising from the principles or facts of natural history which jointly constitute the logic of zoology.

ZOONIC ACID.

'Berthollet,' says Dr. Thomson, has obtained a peculiar acid by distilling animal and vegetable substances, to which he has given the name of zoonic acid.-Ann. de Chim. xxvi. 86. He procured it by distilling the gluten of wheat, the yeast of beer, bones, and woollen rags; and concludes, therefore, that it may be produced by the distillation of all animal substances. To obtain this acid pure, he mixed lime with the distilled liquid, after having separated the oil, which it always contains (for the product of the distillation of animal substances is chiefly oil and carbonate of ammonia). He boiled this mixture till the carbonate of ammonia was exhaled: he then filtered it, added a little more lime, and boiled it again till the smell had gone off entirely. The liquor, which now contained only zoonite of lime, he filtered again, and then added a little water, impregnated with carbonic acid, in order to precipitate any lime which might happen to be dissolved in the liquid without being combined with the zoonic acid. After concentrating the zoonate of lime, he mixed it with phosphoric acid, and distilled it in a retort. At a heat nearly equal to that of boiling water, the zoonic acid passes over in a state of purity. The zoonic acid has an odor like that of meat when frying, and it is actually formed during that process. It has an austere taste. It gives a red color to paper tinged with turnsol. With alkalies and earths it produces salts which do not appear capable of crystallising. It forms a white precipitate in the solutions of acetite of lead and nitrate of mercury. Part of the

zoonic acid seems to be destroyed by the action of heat during the distillation of the zoonate of lime with phosphoric acid; for the liquor, which is in ebullition, becomes brown, and grows black at the end of the operation. Hence Berthollet concludes that the zoonic acid becomes carbon. The zoonate of silver, when kept, becomes gradually brown: hence he concludes that the acid contains hydrogen. Nothing more is at present known concerning this acid. Trommsdorf supposes it the same with the sebacic acid; but this has not been proved, nor even rendered probable.'-Syst. of Chem. vol. ii. p. 162, 163. Thenard indeed has demonstrated that this supposed new acid of Berthollet's is only a combination of acetic acid with animal matter.

ZOONOMIA (from wov, an animal, and vous, a law; q. d. the laws of animated nature), the title of an ingenious and admired work of learning and fancy, by Dr. Darwin.

ZOOPHYTE, in natural history. See ZOOLOGY. ZOOTOMY, of wov, animal, and reμy, I cut, the art or act of dissecting animals, or living creatures. It is therefore the same with anatomy, or rather comparative anatomy. See ANATOMY.

ZOPARITUS, in ancient geography, a town of Asia, in Melitene, on this side of the Euphrates.Ptolemy.

ZOPH, a town of Syria, twenty-five miles S. S. E. of Jerusalem: also a district on the north part of the government of Diarbekir.

ZOPHAR, the Naamathite, one of Job's three uncharitable friends. See ELIHU, and Joв.

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