206 FOURTH REPORT — 1834. 



pterUy (gen. Blatta, Linn.) ; Omoptera, (gen. Cicada, Thrips, 

 Aphis, &c., Linn.) ; Trichoptera, Kirb. (gen. Phryganea, Linn.) ; 

 and Gmaloptera, (gen. Hippohosca, Linn.) ; amounting in all 

 to sixteen. Latreille's name of Suctoria is changed to that of 

 Apt era. 



Mr.MacLeay in his HorcB Entoni. (1821) has proposed Bom- 

 hoptera, Megalopteru, and Rhaphioptera as three new oscu- 

 lant orders in his class Mandihulata, including the genera Sirex, 

 Linn., Sialis, Latr., and Boreas, Latr., respectively. The first he 

 considers as connecting the Hymenojitera and Trichoptera; 

 the second, this last and Neuroptera ; the third, this last and 

 Orthoptera. He regards Dermaptera and Strepsiptera like- 

 wise as osculant orders, the former connecting Orthoptera and 

 Coleoptera, the latter this last and Hymenoptera. 



Blainville* divides the Insects (forming with him his class 

 Hexapuda) into thi'ee subclasses, Tetraptera, Diptera, and 

 Aptera. The first of these contains as subordinate groups the 

 orders Coleoptera, Orthoptera, Hemiptera, Lepidoptera, Neu- 

 roptera, and Hymenoptera. 



In 1823, Dumeril published his Considerations G ene rales sur 

 la Classe des Insectes. His work, however, which is of an ele- 

 mentary nature, oifers nothing new on the subject of classifica- 

 tion. His orders, eight in number, are the same as those of 

 Linnaeus, with the addition of Orthoptera. M. Dumeril advo- 

 cates very strongly the dichotomous, or, as he terms it, the ana- 

 lytical method of arrangement, which he had adopted in his 

 former works. 



In the Fain. Nat. (1825) Latreille adopts as a primary divi- 

 sion of this class the two sections of Aptera and Alata. The 

 former comprises the orders Thysanura, Parasita, and Siphon- 

 aptera (name substituted for that of Suctoria) ; the latter, the 

 remaining orders of the Regne Animal. 



In 1826 appeared the fourth volume of the Introduction to En- 

 tomology, in which Mr. Kirby proposes to adopt twelve orders. 

 Seven oi" these are the same as those of Linnaeus ; the remaining 

 five are Strepsiptera, Dermaptera, Orthoptera, Trichoptera, 

 and Aphaniptera (Siphonaptera, Latr.). 



In the second edition of the Regne Ani7nal,Li-dtre\\\e' s ari'ange- 

 ment is the same as in the first. But in his last work, the Cours 

 d' Entomologie (1831), he has again taken that of the Families 

 Naturelles, excepting that he has adopted one additional order, 

 the Dermaptera of Leach. 



(2.) Our knowledge of the structure of Insects, both external 

 and internal, has been greatly advanced of late years by the re- 



• Principes, ^-c, tab. 7. 



