LÉPIDOPTÉROLOGIE COMPAREE 34I 



Ithysia graecaria, var. istriana, Staudinger. 



This form is much whiter than the type and the markings are 

 gênerai ly weaker although variable in this respect. 



The females. 



Zonaria female needs no description. Its yellow bands sepa- 

 rate it readily although, I possess a totally black female (ab. 

 nigrà) from Russia. The females of the other three species, at 

 first sight so much alike, are easy to separate after a little prac- 

 tice. In ail, the bodies are generally black, more or less closely 

 covered with white hairs. The rudimentary wings are white 

 above, and darker below and they too are provided with white 

 hairs. 



Alpina is the easiest to recognise, for sometimes the fur is 

 yellowish and in ail cases the msect is more closely covered with 

 pale hairs. The great point of différence however, is that the 

 face and collar are v/hite whilst they are black in the others. 



At first sight, the séparation of the other two seems a difhcult 

 problem, but examination soon clears away the trouble. The most 

 obvious point of différence is, that the thorax of italica is much 

 broader than that of grœcaria and like the rest of the body, is 

 covered with fewer and shorter white hairs. The wings too, are 

 less hairy, and, whilst in both species they arc white above, in 

 italica they are jet black beneath; in grœcaria the undersides are 

 obviously paler being marked with a few white scales. The tips 

 of the wings in italica are more pointed. The antennae in grœ- 

 caria are slender and the joints are well marked, but in italica they 

 are thicker and the joints are masked by scales. The most satis- 

 factory points of différence are seen in the legs. Compared with 

 those of grœcaria, italica possesses enormously stout and strong 

 legs and the différence is nowhere more definitcly seen than in 



