466 ° HISTORY OF ENPOMOLOGY. 
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 Monoculus, it returns to the Branchiopods 
again. This circle, through Porcellio Latr., a kind of 
woodlouse, &c., which has only a pair of antennze and at 
first but six legs, is connected with the Ametabola Class, 
which beginning with Glomeris goes by the other Chzlo- 
gnatha (Iulus L.), having also six legs at first, and certain 
Vermes to the Anoplura, and terminates in the Chilopoda 
(Scolopendra L.) their cognate tribe?. 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.hepasses by the osculant class Nycteribida to the 
Arachnida; and beginning with the Acaridea, he goes to 
the Scorpiontdea, and so to the Aranidea or spiders, 
which he connects with the Decapod Crustacea ;—thus 
* See Vor. ITI. p. 25—. and above, p. 385—. 
