CHEMISTRY OF INSECT COLOURS. 37 



fig. 11, from Java. The synonymy of our two British species, 

 as carefully worked out by Herr Snellen, I give in full : — 



Hypenodss costcsstrigalis. 



Cledeohia costastrigalis, Staph., III. iv. p. 20, 1834 ; Wood, 

 Ind. Cat. fig. 772, 1849 ; de Graaf., Bouwst. iii. p. 57, 1862. 



Hypenodes costcestrigalis, Guen., Delt. & Pyr. p. 42, 1854 ; 

 Staint. Man. ii. p. 129, 1859; Siiell., Vlind. p. 494, 1867. 



Hypena tcenialis, H.-S., Panzer, Deutch. Ins. 166, 1, 1839. 



Cledeohia acuminalis, H.-S. ii. p. 442, fig. 619 (pars.), 1845. 



Hypenodes tcsiiialis. 



Pyr alls tcsnialis, Hiib., Pyr. fig. 151, 1796. 



Cramhus albistrigatis, Haw., Lep. Brit. p. 368, 1810. 



Cledeohia alhistrigatm, Staph., 111. iv. p. 20, 1834 ; Wood, 

 Ind. Cat. fig. 771, 1839. 



Hypenodes alhistrigalis, Guen., Delt. & Pyr. p. 42, 1854 ; 

 Staint. Man. ii. p. 128, 1859 ; Hein., Schm. D. i. p. 620, 1859 ; 

 Snell., Tijd. v. Ent. xxx. p. 219, 1887. 



Hypena acuminalis, H.-S., Panzer, Deutsch. Ins. 163, 2, 1839. 



Cledeohia acuminalis, H.-S. ii. p. 442, fig. 619 (pars.), 1845; 

 Wocka, Bresl. Zeits. Ent. pi. 5, fig. 16, 1850. 



(To be continued). 



CONTRIBUTIONS to thr CHEMISTRY of INSECT COLOURS. 



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



Continued from p. 15. 



V. — The Chemical Aspect. F. (continued). 



Passing now to the simply yellow species, we have some 

 very interesting considerations forced upon us. First of all, 

 as to the genus Euchloe : in E. cardamines we see an ex- 

 ceedingly soluble orange pigment. Now there is an extra- 

 British species, E. eupheno, in which the ground colour is 

 yellow, whilst the tips are red : this is a species on which I have 

 not experimented, and its behaviour can therefore only be 

 surmised. The red would, of course, be instantly changed to 

 the ground yellow, but the real interest centres in the question, 

 what next ? The analogy of nearly every red species points to 

 the answer that the yellow (both that already existing and that 

 produced by the transformation of red) would remain unaffected : 

 but, on the other hand, the exceptional behaviour of Delias 

 reminds us that it is not impossible that the total yellow might 

 dissolve away entirely ; whilst the relationship of eupheno to 

 cardamines, with its highly soluble pigment, lends some support 

 to this possibility. We can, then, — failing actual experience, — - 

 only reserve our decision. 



