Introduction. xi 



V. HYMENOPTEROUS. Having four membranous and semi-trans- 

 parent wings, veined like network ; and the tail armed with a 

 sting, as the wasp and bee. 



VI. DIPTEROUS. Having only two wings, as the common house-flies. 

 VII. APTEROUS. Having no wings, as the spiders. 



ORDERS OF VERMES, OR WORMS. 



The sixth and last Linnsean class consisted of Worms, or Vermes. 

 These are slow of motion, and have soft and fleshy bodies. Some ot 

 them have hard internal parts, and others have crustaceous coverings. 

 In some of the species, eyes and ears are very perceptible, whilst 

 others appear to enjoy only the senses of taste and touch. Many have 

 no distinct head, and most of them are destitute of feet. They are, in 

 general, so tenacious of life, that parts which have been destroyed will 

 be reproduced. These animals are principally distinguished from 

 those of the other classes by having tentacula, or feelers, and are 

 divided by Linnaeus into five Orders : 



I. INTESTINA. Are simple and naked, without limbs 5 some of them 

 live within other animals, as the ascarides and tape-worms; 

 others in water, as the leeches ; and a few in the earth, as the 

 earth-worm. 



II. MOLLUSCA. Are simple animals, without shells, and furnished 

 with limbs, as the cuttle-fish, medusa, star-fish, and sea-urchin. 



III. TESTACEA. Are animals similar to the last, but covered with 



shells, as oysters, cockles, snails, and limpets. 



IV. LITHOPHYTA. Are composite Polyps, dwelling in cells in a cal- 



careous base which they produce, as corals and madrepores. 



V. ZOOPHYTA. Are usually composite animals, but do not reside in 

 stony cells. The coral, sponge, and polyps are instances of this 

 order, which also includes the Infusorial Animalcules. 



MODERN SYSTEM. 



It will be found by reading the following sketch of the Modern System 

 that the greatest change has taken place in the latter two classes. 

 The others remain nearly the same in efiect, though their distinctions 

 are different, and the classes are not arranged in the same order. 



According to Cuvier, all animals are arranged in four great divi- 

 sions, which are subdivided into classes and orders, as follows : 



Divisions Classes No. of Orders 



T xr \ 1. Mammalia Nine. 



I VERTEBRATA. 2 Ayeg six> 



Four Classes. Iwenty- 3. Repti i ia .... Four, 



seven Orders. 4 pi es Ei nt . 



