small; in some, sharp; in others, obtuse; in some, very numerous; and in others, very few. Sometimes they are placed in the jaws; sometimes, in the palate or tongue; or, even at the entrance of the stomach. The eyes are, in general, large, and very much flattened, or far less convex than in quadrupeds and birds; this structure being better calculated for giving them an easy passage through the water. In return, the central part of the eye, or what is called the crystalline humour, is of a round or globular shape, in order to give the animal the necessary power of vision, and to compensate for the comparative flatness of the cornea.

3. The organ of smelling, in fishes, is large; and the animals have the power of contracting or dilating it at pleasure. This sense is supposed to be extremely acute. The organ of hearing differs, in some particulars, from that in other animals, and is modified according to the nature of the fish. They are entirely destitute of voice. The particular kind of sound, which some tribes are observed to produce, on being first taken out of the water, is entirely owing to the sudden expulsion of air from their internal cavities. The greater number of fishes are oviparous, producing soft eggs, usually known by the name of spawn. There have been 200,000 ova or eggs found in a carp; in aperch, weighing one pound two cunces, 69,216; in a carp of eighteen inches, 342, 144; and in a sturgeon of one hundred and sixty pounds, there was the enormous number of 1,467,500. The age of fish is determinable by the number of concentric circles of the vertebræ or joints of the back-bone. In the Linnæan arrangement of fishes, the under or belly-fins, are termed ventral, and are considered analogous to the feet in quadrupeds; and it is from the presence or absence of these fins, that the divisions are instituted.

ORDER I. APODES, or footless fishes, are entirely destitute of ventral fins. The genera are. 1. Muræna, eelkind. 2. Gymnotus, electric eel. 3. Anarrhichas, seawolf. 4. Xiphias, sword-fish. 5. Ammodites, launce. 6. Ophidium. 7. Stromateus. 8. Trichiurus.

ORDER II. JUGULARES, or jugular fishes, have the ventral, or belly-fius, placed more forward than the pectoral or breast fins. The genera are: 1. Gadus, haddock,

1

cod, whiting, ling. 2. Uranoscopus, star-gazet. 3. Blennius, blenny. 4. Callionymus, dragonet., 5. Trachinus,

weever.

ORDER III. THORACICI, or thoracic fishes, have the ventral fins situated immediately below the pectoral ones. The genera are: 1. Gymnetrus, comet-fish. 2. Echeneis, sucking-fish. 3. Coryphana, dorado. 4. Zeus, dory. 5. Pleuronectes, flounder, plaice, dab, holibut, sole, turbot. 6. Chaetodon. 7. Spurus. 8. Perca, perch. 9. Scomber, mackarel, bonito, tunny. 10. Mullus, mullet. 11. Acanthurus, thorn-tail. 12. Holocentrus. 13. Sciana. 14. Trigla, gurnards,

ORDER IV. ABDOMINALES, or abdominal fishes, have the ventral fins placed below the pectoral ones, and chiefly inhabit fresh water. The genera are: 1. Cobitis, loach. 2. Silurus. 3. Exocoetus, flying fish. 4. Salmo, salmon, trout, smelt, char, grayling. 5. Esox, pike. 6. Clupea, herring, sprat, shad. 7. Cyprinus, carp, tench, gold-fish, minnow.

CARTILAGINOUS FISHES, improperly admitted into the amphibia by Linnæus, differ from the rest of the fish tribe, in having a cartilaginous or sinewy, instead of a bony skeleton, and in being destitute of ribs. They are divided into two orders, chondropterygii, and branchiostegi.

ORDER I. CHONDROPTERYGII, or such as have no gill

The genera are: 1. Petromyzon, lamprey. 2. Gastrobranchus. 3. Raia, skate, torpedo, stingray. 4. Squalus, shark, saw-fish. 5. Lophius, sea-devil, frog-fish. 6. Balistes, file-fish. 7. Chimera.

QRDER II. BRANCHIOSTEGI, or having a gill-cover. The genera are: 1. Accipenser, sturgeon, beluga. 2. Ostracion, trunk-fish. 3. Tetrodon. 4. Diodon, porcupinefish. 5. Cyclopterus, lump-sucker. 6. Centriscus. 7. Syngnathus, pipe-fish. 8. Pegasus.

CLASS IV.-Amphibia.

1. This class includes all animals who live with equal facility on land or in water, and some others which do not exactly conform to this description. The amphibia from the structure of their organs, and the power they possess of suspending respiration at pleasure, can support a change of element uninjured, and endure a very long ab

stinence. The lungs, differ widely in appearance, from those of other animals. Many of the amphibia are possessed of a high degree of productive power, and will be fur nished with new feet, tails, &c. when by any accident, those parts have been destroyed. Their bodies are sometimes defended by a hard, horny shield or covering; sometimes by a coriaceous, or leathery integument; sometimes by scales, and sometimes have no particular coating. The amphibia, in general, are extremely tenacious of life, and will continue to move and exert many of the animal functions, even when deprived of the head itself. By far the greater part are oviparous, some excluding eggs, covered with a hard or calcareous shell, like those of birds; others, such as are covered only with a tough skin, resembling parchment; and in many, they are perfectly gelatinous, without any kind of external covering, as in the spawn of a common frog. The amphibia are divided into REPTILIA, containing the amphibia pedata, or footed amphibia; and the serpentes, or footless amphibia. In the REPTILIA, there are four genera: 1. Testudo, tortoise, turtle. 2. Rana, frog,* toad. 3. Draco, dragon, or flying lizard. 4. Lacerta, lizards, crocodile, chamæleon, newt, salamander, iguana.

2. The SERPENTES, or serpents, are generally distinguishable from the rest of the amphibia by their total want of feet. One of the most singular properties of the serpent tribe, is that of casting their skin from time to time. When this takes place, so complete is the spoil or coat-skin, that even the external coat of the eyes themselves, makes a part of it. Among the poisonous serpents, the fangs or poisonous teeth are always of a tubular structure, and furnished with a small hole or slit, near the tip, -they are rooted into a particular bone, so jointed to the remainder of the jaw on each side, as to permit the fangs or poisoning teeth to be raised or depressed at the pleasure of the animal. Above the root of each is a glandular reservoir of poison, which, in the act of biting, is pressed into the tube of the tooth, and discharged into the wound

When this animal is in the tadpole state, before it has lost its tail, the circulation of the arterious and venous blood, may be distinctly seen, by a good microscope.

through the hole near the tip. The genera are: 1. Crotalus, rattlesnake. 2. Boa, immense serpents of India and 1 Africa. 3. Coluber, viper. 4. Anguis, blind-worm. 5.. Amphisbæna. 6. Cæcilia. 7. Acrochordus. 8. Hydrus. = 9. Langaya. 10. Siren..

1. The skeleton or bony frame of the animal is, in general, of a lighter nature than in quadrupeds, and is calculated for the power of flight: the spine is immovable, but the neck lengthened and flexible: the breastbone very large, with a prominent keel down the middle, and formed for the attachment of very strong muscles. The bones of the wings are similar to those of the fore legs in quadrupeds, but the termination is in three joints or fingers only, of which the exterior one is very short. What are commonly called the legs, are analogous to the hind legs in quadrupeds, and they terminate in general, in four toes, three of which are commonly directed forwards, and one backwards; but in some birds there are only two toes, in some, only three. All the bones in birds are much lighter, or with a larger cavity, than in quadrupeds. 2. The feathers with which birds are covered, resemble in their nature the hair of quadrupeds, being composed of a similar substance appearing in a different form. Beneath or under the common feathers or general plumage, the skin in birds, is immediately covered with a much finer or softer feathery substance, called down. throat after passing down to a certain distance, dilates itself into a large membranaceous bag, answering to the stomach in quadrupeds: it is called the crop, and its great use is to soften the food taken into it, in order to prepare it for passing into another strong receptacle, called the gizzard. This, which may be considered as a more powerful stomach, consists of two very strong muscles, lined and covered with a strong, tendinous coat, and furrowed on the inside. In this receptacle, the food is cơmpletely ground, and reduced to a pulp. The lungs of

The

* In the birds of prey or accipitres, this is wanting, the stomach being allied to that of quadrupeds.

birds differ from those of quadrupeds in not being loose or free in the breast, but fixed to the bones, all the way down:-they consist of a pair of large spongy bodies, covered with a membrane, which is pierced in several places, and communicates with several large vesicles or air-bags, dispersed about the cavities of the body.

3. The eyes of birds are more or less convex in the different tribes; and in general, it may be observed that the sense of sight is more acute in birds, than in most other animals. Birds have no outward ear, but the internal one is formed on the same general plan as in quadrupeds. Birds are oviparous animals, always producing eggs, from which the young are afterwards excluded. The first appearance of the young, as an organized body, begins to be visible in six hours after the egg has been placed in a proper degree of heat, under the parent animal, The chick, or young bird, when arrived at its full size, and ready for hatching is, by nature, provided with a small and hard protuberance at the tip of the bill, by which it is enabled the more readily to break the shell, and which falls off some hours after its hatching. Birds are divided by Linnæus into six orders-accipitres, pica, passeres, gullinæ, grallæ, and anseres.

ORDER 1. ACCIPITRES, are birds of prey, and feed entirely on animal food. The bill is more or less curved, strong, and often covered round the base by a naked membrane, called a cere; and on each side, towards the tip, is a projection forming a kind of tooth, and serving to tear the prey. The wings are large and strong, and the whole body, stout and muscular; the legs strong and short, the claws much curved, and sharp-pointed. The genera are: 1. Vultur, vultures. 2. Falco, falcon, eagle, hawk, kite. 3. Strix, ow!. 4. Lanius, shrike or butcher-bird.

ORDER II. PICE or PIES. The bill is commonly of a slightly compressed and convex form. They build their nests, or deposit their eggs in trees, and their food is prin cipally of a vegetable nature, though some genera feed on insects. The genera are: 1. Buceros, rhinoceros-bird. 2. Ramphastos, toucan. 3. Psittacus, parrot-kind. 4. Picus, wood-pecker. 5. Paradisea, birds of paradise.