153 



and the Ceratoeampiadce, and in the foUoAving order you will 

 observe how one group represents another opposite to it. 



BOMBYCES. PSEUDO-BOMBYCES. 



5 Attacidae e. g., Attacus, etc. = Ceratocampa, etc. 6 Ceratocanii3iad«. 

 4 BombyciadfE e. g., Mogasoma = Zeuzera, etc. 7 Zeuzeriada?. 

 3 Liparida3 e. g., Orgyia = Psyche, etc. 8 Psychiadte. 

 2 Arctiadfe e. g., Spilosoma = Clostera, etc. 9 NotodontiadjB. 

 1 Litbosiadffi = 



In the following order you Avjll see hoAv these lead from the 

 Sphinges. 



Sphinges verai j ^ Ceratocampiad^. 5 Attaclds, ] f 



7 Zeuzeriada; 8 Psychiadas, I 9 Notodon- 



SphingesadscitffiP^f^*^'^'^"^ ^ Liparida3, 



[ 1 Lithosiadag 4 Bombycladaj 



Or thus: 



r 7 8 



16 5 



P ^ 



12 3 



tiadte 



Acronyc- 



ta, etc. 



Pliisia, 



etc. 



7 8 

 6 9 



Or thus: 5 



1 4 



2 3 



Here the Ceratocampians represent the Sphingians, and the 

 Zeuzerians the ^Egerians ; while the Arctians and Lithosians 

 seem naturally to follow the Agaristians and Callimorphians. 

 Between the Zeuzerians and Arctians there is no affinity ; but 

 there are analogous forms in each, as might be expected from 

 their situation ; e. g., Zeuzera cesculi and Arctia serihonia. So, 

 too, there is no affinity between the PsycUadce and the Lipa- 

 ridce ; but their forms are analogous, e. g., wingless and slug- 

 gish females in each, etc. Moreover, the antennai of Psi/che 

 graminella and the venation of the wings are wonderfully like 

 those of Orgyia. 



It would be impossible for me, within the compass of a single 

 letter, to repeat the various considerations which have confirmed 

 me in this arrangement. Taking the families in a linear series, 

 I have begun in my report with the Lithosians, as intimately 



