Mrs. Loudon's Entertaining Naturalist / Being popular descriptions, tales, and anecdotes of more than Five Hundred Animals.

by Mrs. Loudon

Divisions	Classes	No. of Orders
I. Vertebrata. Four Classes. Twenty-seven Orders.	1. Mammalia	Nine.
	2. Aves	Six.
	3. Reptilia	Four.
	4. Pisces	Eight.
II. Mollusca. Six Classes. Fifteen Orders.	1. Cephalopoda	One.
	2. Pteropoda	One.
	3. Gasteropoda	Nine.
	4. Acephala	Two.
	5. Brachiopoda	One.
	6. Cirrhopoda	One.
III. Articulata. Four Classes. Twenty-four Orders.	1. Annelides	Three.
	2. Crustacea	Seven.
	3. Arachnida	Two.
	4. Insecta	Twelve.
IV. Radiata. Five Classes. Eleven Orders.	1. Echinodermata	Two.
	2. Entozoa	Two.
	3. Acalephæ	Two.
	4. Polypi	Three.
	5. Infusoria	Two.

THE VERTEBRATED ANIMALS

Have a backbone divided into vertebræ or joints, whence they take their name. They have also separate senses for hearing, seeing, tasting, smelling, and feeling; a distinct head, with a mouth opening by two horizontal jaws; a muscular heart, and red blood. The four classes of Vertebrata and their orders are as follow:—

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:—

Section I.—Unguiculated Animals, or Mammalia having Nails or Claws.

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.