103 



may look on the chief features exhibited, whether as presenting an 

 attempt by Z. achillece to reach a form Uke Z. pilose/Ice, supposing 

 the latter to be the more highly developed form which has arisen 

 from an older spotted insect, or on the contrary as an attempt in 

 Z. achilkcB to revert to an ancestral condition more nearly repre- 

 sented now by Z. pilosellce, if the latter be the older form — it really 

 matters little. The line of evolution in either direction is as 

 interesting one way as the other, and the variation of Z. achillecR 

 shows positively either that it is attempting to reach Z. pilosellcB, 

 or, having once been like Z. pilosellce, is attempting to throw off the 

 old shackles and become a five-spot, occasionally, however, reverting 

 to its older form. 



We see, then, that the spots of this Burnet moth are not uniformly 

 separate and distinct, but have a tendency in many specimens to 

 extend themselves so as to unite in pairs, the two upper and outer 

 with each other, the two lower with each other. Occasionally they 

 succeed in doing this more or less, and then it is difficult to ?ay 

 where Z. achillece. leaves off and Z. pilosellce commences. Some of 

 the forms exhibited show this tendency markedly. I think, then, 

 that our study of the general variation of Z. achillece forces one 

 conviction very strongly upon us, and that is that it is nearly related 

 to Z. pilosellce. Taking the characters altogether, this relationship 

 seems to be very close indeed. 



According to Staudinger, Esper's type of this species has a very 

 considerable range. He gives in his "Catalog:" "Central and South- 

 eastern Europe, Northern Italy, Helvetia, Bithynia, Pontus, Armenia, 

 Syria, Siberia." I am not altogether certain that my specimens are 

 of the type form, for Staudinger gives Hiibner's bellis as the form 

 inhabiting the "southern Alpine valleys," and describes it as "major 

 obscurior." 



As may be seen, the male specimens which I exhibit are of a 

 rather dark green tint, not unlike our Scotch Z. exulans and those 

 from the Val Grauson. Perhaps then there is a brighter form which 

 I do not possess. These specimens from Courmayeur, whether they 

 be the type or var. bellis, belong undoubtedly to a very specialised 

 race, with no colour aberration worth speaking about. I exhibit 

 specimens of this species received at various times from Con- 

 tinental collectors. These came from the Jura Mountains and 

 Hungary. 



Hiibner describes a form named vicioe, which Staudinger diagnoses 

 as "maculis minoribus, macula externa rotundata." This, according 

 to Staudinger, is an aberration and not a local race. There is, as 

 may be seen, considerable variation in the size of the spots and the 

 rotundity of the outer spot, but there seems to be every intermediate 

 grade in the specimens I exhibit. Lastly, Menetries describes a 

 yellow variety from the south-east of Armenia under the name of 

 bitorquata, and diagnosed by Staudinger as "alls anticis fiavi- 

 cantibus." I have seen specimens bearing this name n the British 



