SYSTEMATIC INDEX. 



ORDER VI. DIPTEROUS INSECTS. 



These have only two wings. 



18. Fly tribe. Have a proboscis and sucker, the sucker with- 

 out a sheath, and furnished with two bristles page 293 



Flesh-fly 293 | Cheese-fly ib. 



19. Gnat tribe. Have a projecting sucker, which is flexile, 

 single valved, and encloses five bristles 294 



Common Gnat ib. 



ORDER VII. APTEROUS INSECTS. 



These have no wings. 



20. Louse tribe. Have six legs, and the mouth armed with a 

 sucker, capable of being pushed out and drawn back .... 294 



Common Louse ib. 



21. Flea tribe. Have siz legs, formed for leaping 295 



Common Flea ib. 



22. Spider tribe. Have eight eyes, eight legs, and the feelers 

 knobbed at the extremity 2! 



House Spider 296 j Tarantula ib. 



23. Scorpion tribe. Have eight eyes, eight legs, and the feelers 

 armed with claws 297 



Common Scorpion ib.\ 



24. Crab tribe. Have two eyes, and ten legs, the first pair 

 with claws 297' 



Common or Black-clawed Crab ib. 



Lobster 298 



CLASS VI. WORMS. 



This is the lowest class of animated being. They are 

 slow of motion, of soft substance, and able to reproduce 

 parts of their bodies that have been destroyed. Many of 

 them are without any distinct head, and the greater part 

 of them are destitute of feet. 



They are divided into five orders. 



