388 



ARTICULATA: \VOKMS. 



FIG. 523. 



Kotifers Magnified. 

 1 and 2, Brachionus, 3, Stephanoceros. 



They are aquatic animals, minute in sizej mainly 

 microscopic, varying from only one sixteentli of a line 

 to a line in length. They are radiate in general appear- 

 ance, although not radiate in their interior structure. 

 Their organs of locomotion are delicate appendages or 

 cilia arranged around the summit or head. 



PRINCIPAL TOPICS CONSIDERED IN CHAPTER III., SECTION I. 



The Articulata as a Branch. Their external appearance, hard part?, limbs, bilat- 

 eral symmetry, etc. Alimentary canal. Dorsal vessel or heart. Nervous 



eystem. Classification of the Articulata. 



SECTION II. 



SUB-SECTION I. 



The Insecta as a Class. Importance of Entomology. Insecta defined. 



Number of species. Size. Classification of the Insecta. 



SUB-SECTION II. 



The Insects proper. Parts of the body, legs, and wing8. Real nature of 



the wings. Ovipositor. Digestive system. Circulatory system. Respira- 

 tory system. Nervous system. Sight. Hearing. Transformations of In- 

 sects. Larva, Pupa, and Imago. Cocoon. Partial transformation. 



