provided with an air bladder, by the dilatation or compression of which they can sink or rise in the water at will. That branch of Zoology which treats of fishes, their structure, form, habits, uses, &c., is termed Ichthyology, (Gr. icthys, a fish, logos, a discourse). This class is divided into five orders, as follows:

a. Acanthopterygii, (Gr. acantha, a thorn, pteryx, a little wing, or fin), thorny-finned fishes, including the Perch, Flying-fish, King-fisher, Mackerel, Sword-fish, Mullet and others.

b. Malacopterygii, (Gr. malăkos, soft, pteryx, a fin), soft-finned fishes, one of the great sections into which the osseous fishes are divided, comprising the Carp, Pike, Salmon, Trout, Cod, Haddock, Ling, &c.

The

c. Lophobranchii, (Gr. lophos, a crest, branchiae, gills), osseous fishes, that have their gills divided into small tufts. Pipe-fish and Pegasus are examples.

d. Plec'tognathi, (Gr. pleko, I connect, gnathos, a jaw), osseous fishes that have the jaw united by a bony juncture so that it is almost incapable of motion,-including the Sun-fish and Trunk-fish.

e. Chondroptery'gii, (Gr. chondros, a cartilage, pteryx, a fin), fish with cartilaginous and not bony skeletons, embracing the Sturgeon, Shark, Ray, and Lamprey. Sharks are the most formidable and ferocious of all fishes, and often attain an enormous size. There are numerous species, but the white shark is that most dreaded by sailors;-its length is from twenty-five to thirty feet.

STRUCTURE AND CLASSIFICATION OF ANIMALS, CONTINUED. INVERTEBRATED ANIMALS.

DIVISION II. MOLLUSCA.

THE Mollusca, or soft-bodied animals, popularly known as shell-fish, form the second division of the animal kingdom according to the system of Cuvier. Mollusks for the most part have shells forming a defence and covering for their boneless bodies, as the Snail, Oyster, Limpet, Whelk, &c., but some are destitute of this shield, as the Cuttle-fish, the common Garden Slug, &c. The doctrine or science of Shells,

and of the animals that inhabit them, is termed Conchology (Gr. conche, a shell, logos, a discourse.)

The Mollusca are divided into six classes, as follows:1st. Cephalopoda, (Gr. kephale, the head, pous, a foot), footheaded animals, so named from having their organs of motion ranged round their heads, as the Sepia or Cuttle-fish, and the Nautilus. The Cuttle-fish is remarkable for an ink-like secretion from its body, with which when in danger it can darken the water, and so make its escape as it were under a cloud. The Nautilus rides on the waters like a boat, and many suppose that the idea of navigation was borrowed from this singular animal. 2nd. Pterop'oda, (Gr. pteron, a wing), wing-footed animals, very small in size, but abounding in great numbers in the northern seas. The Clio, about an inch long, is the chief among them, and forms the principal food of the Greenland whale.

3rd. Gasterop'oda, (Gr. gaster, the belly), belly-footed animals, so called because they move upon their bellies, which are constructed so as to adhere to surfaces. The common Snail, Limpet and Whelk are specimens.

4th. Aceph'ala, (Gr. a, without, kephale, the head), headless animals, embracing most of the shell-fish used for food, as the Oyster, Muscle, Cockle, &c.

5th. Brachiopoda, (Gr. brachiōn, the arm), arm-footed animals, moving by means of processes resembling arms, and inhabiting bivalve shells. They are not a numerous race at present, but appear to have been so at a former period of the world's history, vast numbers of them being found in the secondary strata of rocks.

6th. Cirrip'eda, (L. cirrus, a lock of hair, pes, the foot), clasperfooted animals, as the Barnacle. These singular creatures attach themselves in enormous numbers to the bottoms of ships, the under side of floating timber, and even to the skins of marine animals.

DIVISION III.-ARTICULATA.

The third sub-kingdom consists of the articulated animals; so named on account of their peculiar structure, which consists of a head and successive members jointed together. It is divided into four classes, as follows:

1st. Annula'ta, (L. annulus, a ring), ring-bodied animals, including all the creatures of the Worm kind, excepting those which inhabit the bodies of other animals.

2nd. Crustacea, (L. crusta, a shell), the class of articulated animals which comprehends the Crab, Lobster, and others possessed of a similar covering.

3rd. Arachnides, (Gr. arachnēs, a spider), spider-kind,—including the House-Spider, the Scorpion, and the Mite. The spider is provided with long feet, but is destitute of wings, and does not undergo transformations like most of the other insects. It feeds on insects, which it catches in its wonderful web, and in patient perseverance it may well be held up as an example to man. 4th. Insec ́ta, (L. insectum, to cut into), small creatures, so denominated from the apparent division of their bodies into two or more portions. They have three principal parts, the head, the thorax, and the abdomen. They have in general six or more legs, besides wings and antennae or instruments of touch; and they nearly all go through certain great changes at different periods of their existence. For example, a caterpillar, after feeding upon leaves till it is fully grown, casts off its caterpillar skin, and presents itself in an entirely different form, in which it has neither the power of moving about nor of taking food; this is the second or chrysalis state. After resting a while, an inward struggle begins, -the chrysalis skin bursts, and from the rent there issues a butterfly, provided with wings to bear it away in search of the honeyed juice of flowers and other liquids that suffice for its nourishment. The science that treats of Insects, as to their structure, varieties, transformations, habits, and uses, is termed Entomology, (Gr. entomon, an insect, logos, a discourse.)

The class Insecta is divided into twelve orders, as follows:a. Myriop'oda, (Gr. myrias, ten thousand, pous, a foot), manyfooted, known from their long slender bodies and great number of feet along their sides.

b. Thysanou'ra, (Gr. thysanoi, fringes, oura, a tail), an order of insects that have the tail fringed with minute hairs, and inhabit old wood.

c. Parasita. (L. parasitus, a hanger on), insects which draw their support from the bodies of other animals to which they attach themselves, including the Louse.

d. Suctoʻria, sucking insects, of which the Flea is an example. These four orders bear the general name of Aptera, or wingless insects, (Gr. a, without, pteron, a wing).

e. Coleoptera, (Gr. koleos, a sheath, pteron, a wing), sheathwinged, to which order belong the Beetle, Death-watch, Cock-chafer and many others.

f. Orthoptera, (Gr. orthos, straight), straight-winged insects, of which the Grass-hopper and Locust are examples. Swarms of Locusts, particularly in Africa, so great as to darken the very sun, frequently fall upon the land and eat up every blade of vegetation. To use the expressive language of holy writ, "The land before them is as the garden of Eden, but behind them like a wilderness."-Joel ii. 3.

g. Hemiptera, (Gr. hemi, half), half-winged insects, including the Bug, Aphis and Fire-fly.

h. Neuroptera, (Gr. neuron, a nerve), nerve-winged insects, comprehending the Dragon-fly, May-fly, Ephemeron, and the Termite or White-ant.

i. Hymenoptera, (Gr. hymen, a skin), membrane-winged insects, including the Ant, Bee, and some others. The Bee and the Ant are insects of peculiar interest, on account of their social and industrious habits, having become proverbial for ingenuity and diligence. A hive of Bees usually consists of about a thousand males or drones, seventeen or eighteen thousand imperfectly developed females or workers, and one female, much larger than the rest, called the queen, being the only real mother in the hive. j. Lepidoptera, (Gr. lepis, a scale), scaly-winged insects;-the Moth and Butterfly are well-known examples. Many thousand kinds of Butterflies have been reckoned. They exceed all other insects in the beauty of their colours. In Brazil are some of great size- -one kind measuring nearly a foot between the extreme points of the wings.

k. Strepsip'tera, (Gr. streptos, twisted), twisted-winged insects, an order including the family of the Stylops.

1. Diptera, (Gr. dis, twice), two-winged insects, of which the Gnat and House-fly are familiar specimens.

DIVISION IV.-RADIATA.

The fourth division of the animal kingdom is the radiata, so called on account of their figures being generally branched or radiated, though, as this department of nature has not yet been

well investigated, it is probable that some more comprehensive designation will in time be given to it. This division comprehends five classes, as follows:

1st. Echinodermata, (Gr. echinos, a hedge-hog, derma, the skin), prickly-skinned animals, of which the Sea-urchin and Star-fish are familiar examples, being often found on the shore after the sea has receded.

2nd. Entozoa, (Gr. entos, within, zoon, an animal), a general name for those parasitical creatures that infest the intestines of larger animals and even the brain, the liver and other parts of the body. One, called from its shape the Tapeworm, sometimes reaches the length of a hundred feet. 3rd. Acalephae, (Gr. akatephe, a nettle), an order of rayed animals well-known by the name of Sea-nettles. They are of gelatinous structure, and remarkable for their stinging powers. The Medusa or Sea-jelly is an example. 4th. Pol'ypi, (Gr. polus, many, pous, a foot), sea-animals with many feet or roots. These animals are commonly known as corals; and an idea was formerly generally entertained that they were stony animals, whence the name Zoophytes, (Gr. zoon, an animal, phyton, a plant). Such is the enormous accumulation of stony envelopes formed by them in certain seas, that islands are produced, coasts extended and harbours blocked up by them. 5th. Infuso'ria, (L. In, fusum, to pour), animalcules, found abundantly in certain animal and vegetable infusions. When we place a drop of any decayed infusion of animal or vegetable matter under a powerful microscope, we discover in that drop various forms of living beings; some of a rounded and some of lengthened form, and some exhibiting ramifications shooting in all directions; but all apparently of a soft transparent gelatinous texture. They have an internal structure resembling that of the higher animals, exhibiting muscles, intestines, teeth, different kinds of glands, eyes, and nerves. Ehrenberg has described more than five hundred species of animalcules; he has found them in fog, in rain, and in snow.

ANIMALS AND THEIR COUNTRIES.

(Compiled).

Pre-pon'der-ance, n. (L. pondus), | Rhi-noc ́er-os, n. (Gr. rhin, keras), superiority of rank or influence. a huge wild beast of the East