SUCTORIA. FLEAS. COLEOPTERA. 31 



ORDER OF SUCTO'RIA. 



5. Suctorial insects, like the preceding, are ap'terous, but they 

 do not undergo metamorphosis. The body is very much com- 

 pressed (jig. 22), and the hind legs are adapted to leaping. The 

 mouth is extended in the form of a trunk or beak, which contains 

 three bristle-like lancets, and performs the functions of a sucker. 

 They undergo complete metamorphosis, and in the larva state, 

 are in form of little worms without feet ; in the imago or perfect 

 state, they live on quadrupeds or birds. 



This order comprises but a single genus, that of the Fleas. 



6. The common flea Pulex irritans (j#g'.22) lives upon dogs, 

 cats, and men, whose blood it sucks. The chigre Pulex pene- 

 trans very common in the warm parts of America, is armed 

 with a beak as long as its body. The female carries her eggs 

 in a sack under the abdomen, and by its rapid 



growth, this part in a short time acquires the 

 size of a small pea, while the animal itself is 

 scarcely as large as a common flea. It in- 

 sinuates itself beneath the skin, and into the 

 flesh, particularly about the feet and toes, F - r>2_ 

 where it deposits its eggs, and sometimes 

 causes great pain and ill-conditioned sores. The only remedy 

 is to remove the sack of eggs with a needle, and fill the hole 

 with strong mercurial ointment. This will be found effectual. 

 It also attacks monkeys, dogs, &c. 



ORDER OF COLEOFTERA. 



7. The order of Coleop'tera (from the Greek, koleos, a case, 

 and pteron, wing) comprises insects which have a mouth armed 

 with jaws, and four wings, differing from each other in texture. 

 The first pair are horny elytra (from the Greek, elittron, a 

 sheath), which are not suitable for flight, but constitute a covering 

 or shield for the second pair, which are membranous, and when 

 in a state of repose, folded transversely. 



8. The tegumentary envelope of these insects is almost always 

 remarkably hard, and sometimes forms a solid, and almost crus- 

 taceous cuirass. The mouth is formed for the mastication of 

 food, and is armed with a pair of mandibles, a pair of maxillee, 

 bearing palpi, and a labium or lower lip, also bearing palpi (fig. 

 4). The wings possess peculiarities of structure which it is im 

 portant to noie : the first pair are of the same consistence as other 



5. How is the order Sucto'ria characterized ? 



6. What are chigres ? 



7. What are the characters of the order Coleop'tera? 



8. What are the characters of the mouth of Coleop'tera ? What is the 

 nature of the wings ? How is the abdomen attached to the thorax ? 



