I. Primates.—Having the upper front teeth, generally four in number, wedge-shaped, and parallel; and two teats situated on the breast, as the apes and monkeys.

II. Bruta.—Having no front teeth in either jaw; and the feet armed with strong hoof-like nails, as the elephant.

III. Feræ.—Having in general six front teeth in each jaw; a single canine tooth on each side in both jaws; and the grinders with conic projections, as the dogs and cats.

IV. Glires.—Having in each jaw two long projecting front teeth, which stand close together; and no canine teeth in either jaw, as the rats and mice.

V. Pecora.—Having no front teeth in the upper jaw; six or eight in the lower jaw, situated at a considerable distance from the grinders; and the feet with hoofs, as cattle and sheep.

VI. Belluæ.—Having blunt wedge-shaped front teeth in both jaws; and the feet with hoofs, as horses.

VII. Cetacea.—Having spiracles or breathing-holes on the head; fins instead of fore feet; and a tail flattened horizontally, instead of hind feet. This order consists of the narvals, whales, cachalots, and dolphins.

I. Rapacious Birds (Accipitres).—Having the upper mandible hooked, and an angular projection on each side near the point, as the eagles, hawks, and owls.

II. Pies (Picæ).—Having their bills sharp at the edge, somewhat compressed at the sides, and convex on the top, as the crow.

III. Passerine Birds (Passeres).—Having the bill conical and pointed, and the nostrils oval, open, and naked, as the sparrow and linnet.

IV. Gallinaceous Birds (Gallinæ).—Having the upper mandible arched, and covering the lower one at the edge, and the nostrils arched over with a cartilaginous membrane, as the common poultry.

V. Waders (Grallæ).—Having a roundish bill, a fleshy tongue, and the legs naked above the knees, as the herons, plovers, and snipes.

VI. Swimmers (Anseres).—Having their bills broad at the top, and covered with a soft skin, and the feet webbed, as ducks and geese.

I. Reptiles.—Having four legs, and walking with a crawling pace, as the tortoises, toads, and lizards.

II. Serpents.—Having no legs, but crawling on the body.

III. Nantes.—Living in the water, furnished with fins, and breathing by means of gills. These are true Fishes, principally of the group termed Chondropterygii, or Cartilaginous Fishes, by Cuvier.

I. Apodal.—Having no ventral fins, as the eel.

II. Jugular.—Having the ventral fins situated in front of the pectoral fins, as the cod, haddock, and whiting.

III. Thoracic.—Having the ventral fins situated directly under the pectoral fins, as the perch and mackerel.

IV. Abdominal.—Having the ventral fins on the lower part of the body below the pectoral fins, as the salmon, herring, and carp.

I. Coleopterous.—Having elytra, or crustaceous cases covering the wings; and which, when closed, meet in a straight line along the middle of the back, as the cockchafer.

II. Hemipterous.—Having four wings, the upper ones partly crustaceous, and partly membranous; not divided straight down the middle of the back, but crossed, or incumbent on each other, as the cockroach.

III. Lepidopterous.—Having four wings covered with fine scales almost like powder, as the butterflies and moths.

IV. Neuropterous.—Having four membranous and semi-transparent wings, veined like network; and the tail without a sting, as the dragon-fly and ephemera.

V. Hymenopterous.—Having four membranous and semi-transparent wings, veined like network; and the tail armed with a sting, as the wasp and bee.

VI. Dipterous.—Having only two wings, as the common house-flies.

VII. Apterous.—Having no wings, as the spiders.

I. Intestina.—Are simple and naked, without limbs; some of them live within other animals, as the ascarides and tape-worms; others in water, as the leeches; and a few in the earth, as the earth-worm.

II. Mollusca.—Are simple animals, without shells, and furnished with limbs, as the cuttle-fish, medusa, star-fish, and sea-urchin.

III. Testacea.—Are animals similar to the last, but covered with shells, as oysters, cockles, snails, and limpets.

IV. Lithophyta.—Are composite Polyps, dwelling in cells in a calcareous base which they produce, as corals and madrepores.

V. Zoophyta.—Are usually composite animals, but do not reside in stony cells. The coral, sponge, and polyps are instances of this order, which also includes the Infusorial Animalcules.

I. The Mammalia are all furnished with mammæ, or teats, through which they give milk to their young, which they bring forth alive. They have warm blood, which all circulates from the heart through the lungs, and returns to the heart before it passes through the body. Their skins are naked, or covered with wool or hair, and their mouths are generally furnished with teeth. There are eleven orders, which are thus distinguished:—

I. Bimana, or two-handed. This order contains only the human species.

II. Quadrumana, or four-handed. This order contains the apes, baboons, and monkeys, and the lemurs.

III. Cheiroptera, the bat family.

IV. Carnivora, or beasts of prey. This order is divided into the following three tribes:—

1. The Insectivora, consisting of those animals which live upon insects, as the hedgehog, the shrew, and the mole.

2. The Carnivora proper, consisting chiefly of the cat family, including lions, tigers, and their allies; the bear family, including the badger, the coati-mondi, the racoon, &c.; the dog family, including the wolf and the fox; the weasel family; the civet-cats; and the hyæna.

3. The Amphibia, consisting of the seals, and other allied animals.

V. Marsupialia, including the opossums and the kangaroos.

VI. Monothrema, containing the Echidna and Ornithorhynchus of Australia.

VII. Rodentia, or gnawing animals. The principal of these are the squirrel family, mice and rats, hares and rabbits, the beaver, the porcupine, and the guinea-pig.

VIII. Edentata, or toothless animals, that is, without front teeth. The principal of these are the sloths, the armadillos, and the ant-eaters.

IX. Pachydermata, or thick-skinned animals. The principal of these are the elephant, the hippopotamus, the rhinoceros; the horse family, including the ass, the mule, the zebra, and the quagga; the wild boar family, and the tapir.

X. Ruminantia, or ruminating animals, the principal of which are the camel family, the deer family, the giraffe, the antelope family, the goat family, the sheep family, and the ox family.

XI. Cetacea, or sea mammalia, the principal of which are the whale family, the dolphin family, the manati, the porpoise family, and the narwhal, or sea-unicorn.

1. Raptores, or birds of prey. These birds are distinguished by a very strong and sharp bill more or less curved, but always hooked at the extremity of the upper mandible, which is covered at the base with a kind of skin called the cere. The nostrils are usually open. The legs are very strong, the feet are large, and the toes, which are four in number, are armed with very strong, sharp, curved claws. The principal raptorial birds are the vultures, including the condor; the falcon family, including the eagles, hawks, kites, and buzzards; and the owls.

2. Insessores, or perching birds. These birds have all feet formed for perching, the hind toe springing from the same place as the other toes, which gives them great power of grasping. Their legs are of moderate length, and their claws not sharply curved. This order includes the thrushes, nightingales, and all the finest songsters of our groves, with the robin-redbreast, the sparrow, and other birds seen about dwellings, the swallows, the larks, the crow family, the kingfishers, the birds of paradise, and the humming birds.

3. Scansores, or climbers. These birds have two toes before and two behind. This construction gives them such great power of climbing, that they can ascend the perpendicular trunk of a tree. The principal birds in this order are the parrots, the cuckoos, and the woodpeckers.

4. Rasores, or gallinaceous birds. These birds have the head small in proportion to the body. The bill is generally short, with the upper mandible somewhat curved. The nostrils have usually a protecting fleshy membrane. The tarsus, or lower part of the leg, is long and bare, and there are four toes, those in front being united by a slight membrane, while that behind is generally higher up the leg, and smaller than the others. This order comprises most of the birds used as food, and includes the peacock, the turkey, the common cock and hen, the partridge, the pheasant, and the pigeon family.

5. Grallatores, or Waders. These birds are characterised by their long and slender legs, and by the thighs being more or less bare. There are three anterior toes, more or less united at the base by a membrane, or rudimentary web. The hind toe is wanting in some members of the order. This order contains the ostrich family, the bustards and plovers; the cranes, herons, and storks; and the snipes and woodcocks.

6. Palmipedes, or web-footed birds. These birds have the legs and feet short, and placed behind, with their fore toes united by a thick and strong membrane. The neck is much longer than the legs, and their bodies are covered with a dense layer of down beneath the outer plumage, which is close, and imbued with an oily fluid that repels the water. The principal birds in this order are the grebes, the auks and penguins, the petrels, the pelican and cormorant and the swans, ducks, and geese.

THE REPTILIA,

Or Reptiles, have neither hair, wool, nor feathers, and their bodies are either naked, or covered with scales. Some lay eggs, and some bring forth their young alive. Some have gills, and others lungs, but the latter have only a portion of the blood passing through them; and thus the blood of reptiles is cold, as it is respiration which gives the blood heat. The senses of reptiles are dull, and their movements are either slow or laborious. The following are the four orders into which this class is divided:—

THE PISCES,

Or Fishes, are defined by Cuvier to be vertebrated animals with red blood, breathing through the medium of water by means of their branchiæ or gills. To this definition may be added, that fishes have no neck, and that the body generally tapers from the head to the tail; that most of the species are furnished with air-bladders which enable them to swim; and that their bodies are generally covered with scales. The heart has only one auricle, and the blood is cold. The gills require to be kept moist to enable the fish to breathe, and as soon as they become dry, the fish dies. Thus fishes with large gill openings die almost as soon as they are taken out of the water; while those with very small openings, like the eel, live a long time. Fishes have no feet, but are furnished with fins. The scientific knowledge of Fishes is called Ichthyology. Fishes are first divided into two great series, viz. the Bony Fishes, and the Cartilaginous Fishes, and these are again subdivided into nine orders, as follows:—

Osseous or Bony Fishes.

Chondropterygii, or Cartilaginous Fishes.

Of the bony fishes the Acanthopterygii, or fishes with hard spiny fins, are divided into fifteen families, the principal of which are the perch family, the mailed cheek fishes, including the gurnards, the flying fish of the Mediterranean, and the sticklebacks, or jack banticles; the mackerel family, including the tunny, bonito, and sword-fish; the pilot-fish, the dolphin of the Mediterranean, so celebrated for the beauty of its dying tints, and the John Dory. Among the Malacopterygii abdominales, or soft-finned fishes, that have their ventral fins suspended from the abdomen, the most interesting are the carp family, the pike family, the flying-fish of the ocean, the salmon family, and the herring family, including the sprat, pilchard, and anchovy.

The Malacopterygii sub-brachiati are soft-finned fishes, with the ventral fins beneath the pectorals; the principal of which are the cod family, including the haddock, whiting, and ling; the flat-fish family, including soles, turbots, plaice, and flounders; and the suckers or lump-fish.

The Malacopterygii apodes are confined to the eel family.

The Lophobranchii include the pipe fish, and other fishes of similar form.

The Plectognathi comprise the very singular forms of the balloon-fish, the sun-fish, and other similar fishes.

The Chondropterygii, or Cartilaginous fishes, are divided into three orders, viz. the Sturiones, or sturgeon family; the Selachi, or sharks and rays, including the torpedo; and the Cyclostomi, or lamprey family. The last two orders were included by Cuvier in a single one.

THE MOLLUSCOUS ANIMALS

Have no bones except their shells. Their sense of feeling appears to be very acute, but the organs for the other senses are either wanting or very imperfect. The blood is cold and white, and the heart often consists of only one ventricle; a few of them have imperfect lungs, but the greater number breathe through gills. They have all the power of remaining a long time in a state of rest, and their movements are either slow or violently laborious. Some of them appear incapable of locomotion. They produce their young from eggs, but some lay their eggs on a part of their own body, where the young are hatched. The following are Cuvier’s six classes:—

THE ARTICULATED ANIMALS

Have no back-bone. The covering of the body is sometimes hard and sometimes soft, but it is always divided into segments by a number of transverse incisions. The limbs, when the body is provided with any, are jointed; and they can be separated from the body without any serious injury being sustained by the animal, new limbs being shortly after formed to replace them. The senses of tasting and seeing are more perfect than those of the Mollusca, though that of feeling seems much less acute. In other respects the four classes differ considerably from each other.

[The Entozoa, or Intestinal Worms, placed by Cuvier and others among the Radiata, are now arranged amongst the lowest forms of articulated animals, as are also those animalcules known as Rotifera.]

III. The Arachnida are defined by Lamarck to be oviparous animals, provided with six or more articulated legs, not subject to metamorphosis, and never acquiring any new kinds of organs. It is now known, however, that some mites undergo a sort of metamorphosis, having only six legs when first hatched, and passing through a quiet pupa stage before acquiring their perfect form. Their respiration is either by means of air-sacks, which serve for lungs, or of a kind of tube with circular openings for the admission of air. There is a rudimentary heart and circulation in most of the species. There are two orders; those with lungs, and those without.

Order I. Pulmonariæ. The Arachnides comprised in this division have air-sacks, which serve for lungs, a heart with distinct vessels, and from six to eight simple eyes. There are two distinct families: viz. Araneides, comprising all the spiders and spinners; and Pedipalpi, comprising the tarantula and scorpions.

Order II. Tracheariæ. These Arachnides are distinguished by their respiratory organs, which consist of radiated or branched tracheæ, receiving air by two circular openings. Their eyes vary from two to four. The principal animals belonging to this division are the long-legged spiders (Phalangium), and the mites (Acarus), including the gardener’s pest, the little red spider (Acarus telarius), the cheese mite (Acarus Siro), and the harvest bug (Acarus or Leptus autumnalis).

IV. The Insecta form the fourth and last class of articulated animals, and they derive their name from the Latin word insectum, which signifies “cut into,” in allusion to the distinct divisions of head, thorax, and abdomen in the true insects: and in contradistinction to the Annelides, the bodies of which present no such divisions. The true insects are defined as animals without vertebræ, possessing six feet, with a distinct head furnished with antennæ, and breathing through stigmatic openings, which lead to interior tracheæ. The Myriapoda have, however, more feet. The following are the twelve orders into which this class is divided.

1. Coleoptera (from two Greek words signifying sheathed wings). These are the beetles, which are all furnished with membranous wings, with which they fly, and which are protected by horny upper wings, or wing-cases, called elytra. They are all masticators, and are all provided with mandibles or projecting jaws, and maxillæ.

2. Orthoptera, or straight-winged insects. This order comprises the crickets, grasshoppers, locusts, and similar insects. They have their upper wings of the consistence of parchment, and have mandibles and maxillæ.

3. Hemiptera, or half-winged insects, have frequently half the upper wing membranous, like the under ones, while the other half is leathery. To this division belong the bugs, the water-scorpions, the cicadæ or froghoppers, and the aphides. These insects have neither mandibles nor maxillæ, but in their place have a sheath and sucker.

4. Neuroptera, or nerved-winged insects, such as the dragon-flies, have both pairs of wings membranous, naked, and finely reticulated. The mouth is adapted for mastication, and furnished with mandibles and maxillæ.

5. Hymenoptera, membranous winged insects, such as bees, wasps, ichneumon flies, &c. All the four wings are membranous, but they have fewer nervures, and are not reticulated like those of the preceding order. The mouth is furnished with mandibles and maxillæ, and the abdomen is terminated either by an ovipositor or a sting.

6. Lepidoptera, or scaly-winged insects. These are the butterflies and moths, which are characterised by the farinaceous or scaly aspect of their wings, and the tubular or thread-like extension of the parts of the mouth.

7. Strepsiptera or Rhipiptera, with twisted wings. These creatures resemble the ichneumon, in laying their eggs in the bodies of other insects, though they generally attack wasps and bees. The principal genera are Xenos and Stylops. They are generally considered to be closely allied to the Beetles.

8. Diptera, or two-winged insects, including the flies. The mouth is furnished with a proboscis, and there are two small wings called halteres placed behind the true wings, which act as balancers.

9. Suctoria, or sucking insects, such as the flea, which have no wings, but are furnished with an apparatus for sucking blood.