ARICIA MEDON. 237 



basal spot appears in each forewing. He observes that in the north 

 there is generally a brown tint in the ground colour of the undersides, 

 the pearly grey being almost confined to the south. The general 

 variation in size is not great, though occasionally both large and small 

 specimens are found. The usual range is from 22mm. to 30mm., but 

 Briggs records specimens from Folkestone of only 15mm. in expanse ; 

 these, however, are probably measured from tip to tip of the forewings, 

 which would give an expanse of about 18mm. if measured from the 

 centre of the thorax to the tip of each wing, which would still be very 

 small. On the other hand ? s up to 32mm. are far from rare. 



The examples of Northern Europe do not, as a rule, display more 

 than a slight amount of orange, and the allous form is by no means 

 unusual ; the orange is generally in separate lunules on the hindwings, 

 and separate spots on the forewings when it occurs on these ; it is not, 

 however, deficient in brilliancy. A specimen is noted by Sparre 

 Schneider from Christiania with the black discoidal spot of the 

 forewing surrounded by white. There is great variation in size. The 

 prevailing form in Germany is that of central England, with more 

 orange-red than Hiibner's illustration which he calls agestis, but less 

 than Bergstrassers astrarche in the $ , though the 2 , the sex he 

 illustrates, is generally of a form corresponding with his figure. In 

 the Brit. Mas. coll. is a specimen of ab. albiannulata from Berlin. 

 The form without orange spots is also to be found in North Germany, 

 and is, in fact, Hufnagel's type. 



In Switzerland the variation is not so extensive as would naturally 

 be expected, considering the different altitudes at which the species is to 

 be found. The first brood, even in the plains, rarely shows any orange- 

 red on the forewing in the $ , being typically of the semi-allous form, and 

 sometimes of the allous form, entirely without spots, which is, however, 

 less scarce in the mountains. The second brood in the Rhone Valley 

 often approaches var. aestiva, especially in the colouring of the 

 underside, but the orange of the upperside spotting is not very vivid, 

 much less so than in many British specimens. The upperside ground- 

 colour is, in the mountains, and in the first brood in the plains, 

 generally speaking, very dark, and the specimens being mostly small, 

 are of the alpina form. The underside ground-colour is generally grey, 

 but often of a somewhat darker shade than is usual in England ; it is 

 very rarely that the $ s show the slightest tinge of brown, except, as 

 stated above, in the second brood of the hot Rhone Valley. The 

 mountain specimens, for instance those taken in July on the Albula 

 Pass, are practically indistinguishable from the June specimens from 

 Bex or Vernayaz, though the average of the former may be slightly 

 smaller. Specimens taken in July, at 4,000 to 5,000ft., often show 

 more orange spotting, and a brown tinge in the ground-colour of the 

 underside in the $ s. 



In the more mountainous parts of France there is not more orange- 

 red than in the last-mentioned Swiss examples, but Oberthiir observes 

 that in the plains the wings are adorned on the upperside with a 

 strongly accentuated border of interneural spots of a vivid orange-red 

 (his var. gallica) ; on the underside the ground-colour varies from 

 whitish grey to brown. The marginal black spots on the hindwing 

 often show' on the upperside. 



