hnoion forms of South African Butterflies. 237 



the brilliant silvery-blue gloss from the base outward 

 is greatly extended, so as to reduce the orange ground- 

 colour in the hind-wiug to a more or less imperfect hind- 

 marginal macular border, and (in conjunction with a very 

 broad blackening of the apical area) wholly obliterating it 

 in the fore-wing. These three examples were taken at 

 long intervals; the first as far back as the year 1815 at 

 Genadendal, Cape Colony, by William Burchell, the second 

 and third not till 1865 and 1868 respectively, but both on 

 Table Mountain. I never met with a similar example 

 during my own long collecting experience in South 

 Africa, although (as noted fully in my " South-African 

 Butterflies," vol. ii) I had found considerable variation 

 in the direction of the examples in question, and had 

 received from Kaffraria specimens in which the silvery- 

 blue suffusion was not very much less extended.* I was 

 thus naturally led to regard the three specimens above 

 mentioned as individual extreme aberrations of a variable 

 species ; but Mr. Feltham's discovery during the summer 

 of 1899-1900 of a considerable number of this brilliant 

 variation in a very restricted area on the summit of the 

 Muizenberg mountain in the Cape Peninsula — see his 

 most interesting account in Proc. Ent. Soc. Lond., Nov, 

 7th, 1900, pp. xix-xxi — has put an entirely different aspect 

 on the case. Mr. Feltham took at various dates from 22nd 

 October to 4th March, 44 <^ <^ and 11 $ $ ; he describes 

 considerable variation among the $ $ — especially as regards 

 the spots of orange which sometimes occur in the broad 

 black apical and hind-marginal space in the fore-wing, and 

 the extent of the orange hind-marginal border in the 

 hind-wing — and notes that the ^ $ were " distinguishable 

 from those of typical Thysbe by their smaller size, broader 

 black hind-marginal baud and larger spots above." I fully 

 agree with his conclusion that the facts he mentions " seem 

 to justify us in regarding this mountain form as a distinct 

 dark variety rather than an accidental sport." 



The two $ $ and a ^ exhibited at the Entomological 

 Society at the Meeting mentioned were presented by Mr. 

 Feltham to the British Museum, and I am permitted to 

 give the accompanying figures of the $ and of the ^ which 

 exhibit some remains of the typical orange ground-colour 



* Three similar but larger S S were taken by Mr. C. N. Barker 

 near Port Elizabeth, Cape Colony, in the year 1895, and were pre- 

 sented to nie with the rest of his fine collection in 1898. 



