478 HISTORY OF ENTOMOLOGY. 



I have before sufficiently noticed these Classes, or 

 Orders as Mr. MacLeay terms them, of the Sub-king- 

 dom Annulosa : I shall here therefore only throw out 

 a few remarks on their composition. With regard to 

 their circular distribution in the Crustacea, Mr. MacLeay 

 thinks the series runs from the Branchiopods or Mono- 

 culus L. to the Decapods or Cancer L. ; and so on, till by 

 means perhaps of the genus Bopyrus, which Fabricius re- 

 gards as a MonoculiiS) it returns to the Branchiopods 

 again. This circle, through Porcellio, a kind of wood- 

 louse, &c., which has only a pair of antennas and at first 

 but six legs, is connected with the Ametabola Class, 

 which beginning with Glomeris goes by the other Chilo- 

 gnatlia (lulus L.), having also six legs at first, and certain 

 Vermes to the Anoplura, and terminates in the Chilopoda 

 (Scolopendra L.) their cognate tribe a . From the Ameta- 

 bola Mr. MacLeay proceeds to the Mandibulata, between 

 which two groups he has discovered no osculant one, but 

 he takes the Anoplura of the former as the transit to the 

 Coleoptera in the latter ; from whence passing to the Or- 

 thoptera, &c., he finally returns by the Hymenoptera. 

 Between the Mandibulata likewise and Haustellata he 

 finds no osculant class : but as the affinity between the 

 Trichoptera and Lepidoptera is evident, proceeding by 

 the Homoptera he returns to the Lepidoptera by certain 

 Diptera, as Psychoda, &c. From the Aptera Lam. or 

 Pulex L. he passes by the osculant class Nycteribida to 

 the Arachnida ; and beginning with the Acaridea, he 

 goes to the Scorpionidea, and so to the Aranidea or spi- 

 ders, which he connects with the Decapod Crustacea ; 



* See VOL. III. p. xJo . and above, p. 394 . 



