VARIATION. 



11 



^^ ARI AT 10 N. 



Ox THK DISTRIBUTION OF THE VARIOUS FORMS OF OpORABIA DILUTATA. 



The following Table on the various forms of this species may prove 

 useful to those who are at work on the distribution of local forms : — 



I should be glad of lists from all parts of the country. — .J. W. Tutt. 



The pale form of (K ililutata used to be largely in excess of the 

 other forms at Eedhill some 20 years ago. Here the insect is not 

 common, and its place seems to be taken by the more silky triangular- 

 winged fn<f»w//m/7rt.— Sydney Webb, Dover. March, 1896. 



Variation of Xanthia fulvago.— I was much interested to note, 

 though only a " beginner," the account of the variation occurring in 

 Xanthia fulvago, Linn. Perhaps the following notes on the same 

 subject may prove of interest. In going through my series of 23 

 specimens, all captured at Wylam-on-Tyne, I find the following 

 forms : — (1) Light ground colour with central spot dark = fiairsccns, 

 Esp. Of this form, which is usually fairly plentiful, I have seven 

 specimens. It is, however, more abundant in some years than in 

 others. Some have the faintest possible traces of the usual bands. 

 (2) Light, with distinct red markings — J'tdrac/o, Linn. I have 

 only five of this form, but it is usually fairly well represented among 

 both captured and bred specimens. (3| Pale, with dark purplish 

 markings = ab. niij'iisa {cerai/o, Newm.). The majority of specimens 

 I meet with are of this form, which may be taken as the commonest 

 in this district. (4) Orange-yellow with red markings = ab. aurantia, 

 Tutt. Two specimens only. Besides the above, I have one bred 

 specimen, far below the average size, in which the bands show a 

 tendency to suffusion over the median area of the wings. I have a 

 second specimen, also bred, scarcely one inch in alar expansion.— 

 C. H. Crass, 12, Eastbourne Grove, South Shields. 



In 1894 I bred my present series of X. fidvai/d, which consists of 

 34 specimens. All are of the pale yellow coloration, and are dis- 

 tributed among the various forms as follows : — 



(1) Pale yellow with purple band and markings — 10 specimens. 



(2) Pale yellow with red markings — 7 specimens. 

 (8) Pale yellow with faint markings — 13 specimens. 

 (4) Pale yellow with central spot only — 4 specimens. 



In 1890 I collected a large quantity of sallow catkins, and from these 



