^NS^ AND ^^^^ 



JOURNAL OF VARIATION. 



No. 3. Vol IV. March 15th, 1893. 



1'fiE QEpIlJ^ ^JljiUjilJI: 



With Note.s on Variation, Habcts and Affinities. 



By J. W. TUTT, F.E.S. 



{Continued from page 28.) 



Xaiithia cltrago. — This species aj^pears to have nothing in common 

 with flavago and fnlcago, which I look upon as the true types of tlie 

 genus Xanthia. I have previously mentioned the strange fact that the 

 terminal segment of the pupa in no wa^^ resembles either of the gToups 

 with which it is usually allied, that is, with those Orthosidce like Ghea, 

 or, on the other hand, with those Orthosidce which come near the 

 Hadenidce like T<.miocampa ; in fact, Dr. Chapman calls my attention to 

 its similarity in this respect to Cuspidia (Acronycta), although I do not 

 mean to suggest that it has any close affinity with Acronycta from this 

 isolated fact. At the same time there is no doubt from its general 

 characters, habit of the larva, pupal structure, different arrangement of 

 transverse lines, etc., in the imago, that the moth has no very great 

 affinities with those species with which it is at present gi'ouiied. 



Xanthia citrago is distinctly of two shades of coloui' — a pale orange, 

 almost yellow, and a rich orange approaching the colour of croceago, in 

 fact, one si:)ecimen kindly given to me l)y Mr. Holland quite equals 

 that species in intensity. This coloration is to a certain extent sexual, 

 for whilst a large number of the males and all the females are of the 

 paler tint, a small proportion of the males are of the darker orange 

 coloration ; not that there is any very distinct line of demarcation, but 

 the males are certainly dimorphic, or, at least, have a strong dimorfjhic 

 tendency, the females (at least, not in the large number of specimens I 

 have) certainly not exhibiting this difference in anything like so 

 marked a degree, or, in fact, at all. This dimoi'ijliic tendency in the 

 males is accentuated by the development in most of the richer coloured 

 specimens of a distinct, Avell-marked, dark fascia crossing the centre of 

 the wing between the stigmata, the fasciated appearance being due to 

 the widening of the normally fine central line by a shading of fuscous 

 scales on its outer edge and its union with the reniform, which in these 

 specimens also partakes of a fuscous hue. All my extreme, strongly- 

 marked specimens are, without exception, males. One specimen I have 

 before referred to is very striking, not only from the richness of 

 the ground colour, but from the fact that outwards from the elbowed 

 line it is so suffused with dark scales as to have the appearance of an 

 outer band, as is so common in X. aurago. This, perhaps, shows simply 



