THE GENUS XANTHIA. 27 



its approximation in colour is due to a common habit at the same time 

 of the year, and that this is needed for protection, and is no sign of 

 actual close affinity. I have no information about X. aurago, but, 

 although I am much less struck with the imago differences than I was 

 with citrago, I should not be surprised that its early stages showed 

 some considerable differences from the other three members of the 

 genus. 



Hoporina croceago. — This is of course never included in the genus 

 Xanthia, although generally classified very nearly to it. It is a very 

 beautiful species, and in a manner striking, with its thoracic crest set up 

 prominently, and Avith its white-ringed legs and white-spotted costa. 

 There are no very striking points about the markings, and the colour is 

 particularly invariable in fresh specimens. There are, however, two 

 named varieties. In one of these the ground colour is dark reddish, 

 instead of the normal bright orange colour ^^ fidrago, Hb., and Mr, 

 Nicholson refers to specimens from North Wales, being of a dull brick- 

 red colour. This is probably due to a thick sprinkling of dark fuscous 

 scales, as our ordinary British specimens are frequently sprinkled with 

 such, although never in specimens I have bred or received has this 

 been sufficient to suffuse the whole wing area so as to make a striking 

 variety. There is also a pale yellow variety in Southern Europe, wliicli 

 was named Corsica by Mabille, who writes of it as " whitish-yellow," 

 while, at the same time, he notices the general constancy of the sjDCcies 

 on the Continent. Staudinger writes of it : — " Pallidior, straminea." 

 After hybernation the colour is much faded, and the dark markings 

 stand out prominently. Specimens in very bad condition, too, have a 

 suj^erficial appearance of being melanic. One other minor form of 

 variation is noticeable, that is, the tendency in some specimens to form 

 a distinct central fascia, or, at any rate, a stronger mark than the ordi- 

 nary line. In some it assumes a > - shape, in others, a Y- shape, the 

 former being due to the central line starting from the inner margin, 

 running towards the apex, and then suddenly turning back to the costa, 

 between the stigmata, the latter to its bifurcation in the centre of the 

 wing, the second branch being continued towards the apex. The white 

 hind wings have occasionally a delicate rosy tint, such as one sometimes 

 sees on the fore wings of Cusjndia trklens, Noctua glareosa and a few 

 other sjDecies. 



Croceago hybernates and comes to the sallows in early spring. 

 Although faded in colour, it is remarkable how well the moth keeps 

 its fringes throughout its hybernation, and how well it still simulates 

 the dead oak leaves. The moths copulate in the early spring after hy- 

 bernation, and the moth lays its eggs singly on the dead oak leaves 

 which are still clinging to the tree. Dr. Chapman obtains a consider- 

 able number of eggs from moths in confinement, by enclosing them in 

 a glass jar with dead oak leaves and twigs. Even then, the habit of 

 laying singly is generally carried out, although under such restrictions, 

 it is not surprising that one finds frequently three or four eggs in a 

 batch. The larva hatches as the oak-buds begin to swell and prepare 

 to burst into leaf, and the young larvae rest along the veins of the 

 leaves. It feeds up readily, even in our London gardens, and I have 

 more than once successfully reared the species on some pigmy oaks in 

 my own garden. The larva is full-fed in May, and goes down at once 

 into the ground and forms a cocoon, but it remains in this a very consider- 



