THE CLASSIFICATION OF ANIMALS 115 



axid many others constitute the great order of perching birds 

 (including all the singing birds) called the Passeres. 



Class and branch. — But it is evident that all of these 

 orders, together with the other bird orders, ought to . be 

 combined into a great group, which shall include all the 

 birds, as distinguished from all other animals, as the fishes, 

 insects, etc. Such a group of related orders is called a class. 

 The class of birds is named Aves. There is a class of fashes, 

 Pisces, and one of frogs and salamanders, Batrachia, one 

 of snakes and lizards called Reptilia, and one of the quad- 

 rupeds which give milk to their young called Mammalia. 

 Each of these classes is composed of several orders, each of 

 which includes several families and so on down. But these 

 five classes of Pisces, Batrachia, Reptilia, Aves and Mammals 

 agree in being composed of animals which have a backbone 

 or a backbone-like structure, while there are many other 

 animals which do not have a backbone, such as the insects, 

 the starfishes, etc. Hence these five backboned classes may 

 be brought together into a higher group called a branch 

 or phylum. They compose the branch of backboned ani- 

 mals, the branch Vertebrata (now usually looked on as a 

 sub-branch of the great branch Chordata); all the animals 

 like the star-fishes, sea-urchins and sea-lilies which have the 

 parts of their bodies arranged in a radiate manner compose 

 the branch Echinodermata; all the animals hke the insects 

 and spiders and centipedes and crabs and crayfishes, which 

 have the body composed of a series of segments or rings and 

 have legs or appendages each composed of a series of joints 

 or segments, make up the branch Arthropoda. And so might 

 be enumerated all the great branches or principal groups 

 into which the animal kingdom -is divided. 



TABLE OF BRANCHES AND CLASSES OF ANIMALS 



As the animals referred to in this book are not taken up 

 in a rigorous systematic or classificatory order, but are 



