THE CLASSIFICATION OF ANIMALS 73 



prehensive than families, but the principle on which they 

 are constituted is exactly the same as that already 

 explained. Thus a number of related families are grouped 

 together to form an order. All the fowl-like birds, in- 

 cluding the families of pheasants, turkeys, grouse and 

 quail, all obviously related, constitute the order of gal- 

 linaceous birds called Gallince. The families of vultures, 

 hawks and owls constitute the order of birds of prey, 

 the Raptores, and the families of the thrushes, wrens, 

 warblers, sparrows, black-birds, and many others con- 

 stitute 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 fishes, Pisces, and one of frogs and salaman- 

 ders, Batrachia, one of snakes and lizards called Reptilia, 

 and one of the quadrupeds 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 struc- 

 ture, 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 animals, the 

 branch Vertebrata; all the animals like the starfishes, 

 sea-urchins and sea-lilies which have the parts of their 

 body arranged in a radiate manner compose the branch 

 Echinodermata; all the animals like the insects and 



