CHEMISTRY OF INSECT COLOURS. SOt 



urtictB, Satyrus megcBra, 8. mcera, Epinepliile ianira, Chrysophanus phlceas, 

 Polyommatus alexis, Melitaa phcebus, M. cinxia, Pyryus sao. 



Lepidoptera-Heterocera. — Ahrostola triplasia. 



DiPTERA. — Anthrax (sp. incert.), Tipida (sp. iucert.). 



Hemiptera. — Lygmus militarls, Pyrrhocoris cegyptius. 



HoMOPXERA. — Triecphora sanguinolenta. 



Hymenoptera. — Polistes galUcus, Xylocopa viotacea, Melecta punctata, 

 Osmia cenea, Polynerus (sp. incert.), Allantus (sp. incert.), A. dispar. 



Neuroptera. — Libellula depressa, Limnephilus griseus?. 



Gibraltar. 



Coleoptera. — Nacerdes melanura, Heliotaurus ruficollis, Cetonia 

 squalida, C. hirtella. 



Lepidoptera-Heterocera. — Zygmna sp. — ? 



Hymenoptera. — Anthidium (sp. incert.), Polistes gallicus, Odynerus 

 quadratus, Apis meUiJica. 



Diptera. — Idia sp. — ?, Syrphus halteatus. 



Hemiptera. — LygcBUs militaris. 



Malaga. 



Lepidoptera-Rhopalocera. — Satyrus meone, Colias edusa. 

 Diptera. — Eristalis tenax. 



CONTRIBUTIONS to the CHEMISTRY of INSECT COLOURS. 



By F. H. Perry Coste, F.C.S., F.L.S. 



(Concluded from p. 192.) 



After this exceedingly brief reference to a few cases of 

 variation tliat illustrate my argument, I will venture to indulge in 

 a little prediction. We are often told that the power of pre- 

 diction is the test of a theory's correctness, and I am bold enough 

 to predict with considerable confidence that the following varieties 

 will somewhere or at some time be found naturally occurring. 

 Indeed, it is highly probable that many of them have long since 

 been found and chronicled, but if so I am ignorant of the fact. 

 It will be understood that these unknown varieties are predicted 

 on the strength of the evidence now amassed as to the nature and 

 constitution of the pigmental colours, and are in no sense, of 

 course, intended to be exhaustive of the subject. I merely take 

 typical species, and predict variations which one may expect to 

 occur similarly in other species with similar colouring. I shall 

 take as a guide the tabulation given last year,* and will notice 

 first retrogressive varieties, taking the colours seriatim : — 



Yellow and Orange. 

 E. cardamines (male). — Pale or colourless varieties. 

 G. rhamni. — Pale varieties ; colourless less likely. 



• Entom. xxiii. 24S— 252. 



