94 BRITISH BUTTERFLIES. 



Collioure, a very small race occurs, and Elwes adds that these Collioure 

 specimens have a remarkably well-developed line of white spots on 

 the underside of the hindwings. The undersides of the wings are 

 occasionally brown instead of green ( = ab. brunnea, Tutt, Brit. Butts., 

 p. 196). This condition can be brought about artificially by exposure to 

 excessive moisture, and Barrett states that, when the insect newly emerges 

 from the chrysalis, it shows no trace of green on the underside, the latter 

 being golden-brown as is the colour of the upperside, the green develop- 

 ing as the wings expand. Hodgkinson notes a specimen taken at 

 Witherslack, May 11th, with the underside of the hindwings brown, as 

 in Strymon pruni. South describes an example taken by Dillon, at 

 Clonbrock, in early June, 1893, as having " the forewings rather 

 narrower than in typical specimens ; the upper surface of all the 

 wings fuliginous-brown, and the under surface entirely without 

 the usual green coloration ; the white macular line or band very 

 distinct and regular ; the sexual mark hardly paler than the ground 

 colour, and very obscure." Blachier describes (in litt.) a strange 

 aberration taken at Digne, on May 16th, 1906. The underside of the 

 forewings of an uniform blackish- or very dark olive-grey ; the inner 

 margin of the forewings of a paler shade. According to the degree of 

 the incidence of the light falling on it, the nervures of the forewings, 

 especially near the apex and outer margin, stand out in a shiny 

 emerald green tint. Two white points only on the hindwings, one on 

 the costa, the other lower, between nervures 2 and 3. The upperside 

 is very pale brown, slightly reddish, with the androconial spot dense, and 

 of a deep black tint. The following appear to be the only described forms : 



a. ah. pallida, u. ab. Riibi, Mill., "Ann. Soc. Ent. Fr.," p. 216 (1887).— A 

 remarkable example of this species, in perfect condition, was captured on April 5th, 

 1887, at Cannes, near the Hotel des Pins, by Madame M. Texier. It is of the same 

 form, size, and wing-outline as the type, but the wings above are of an uniform, 

 very warm, tawny-yellow, less so at the base and below the costa which is pointed 

 with grey. The fringe is quite white on all four wings. The whole of the body, 

 above, participates in the abnormal colour of the wings. These, below, would be of 

 a lively flesh-colour, were they not shot with pale watery-green, particularly at the 

 base. The fringes are, here, of a very undecided golden tint. On the hindwings 

 are three veiy small white dots, scarcely visible, situated towards the centre and in 

 line. The antennas are fringed with white and terminated with a lengthened club of a 

 dull purple ; the abdomen and the legs are greyish-white (Milliere). 



It is possible that this specimen should be put among our patho- 

 logical examples. From the description one suspects it to be an 

 individual in which the pallid patches usually confined to limited areas 

 of the wing, have spread over the whole wing-surfaces, producing an 

 uniform tint. 



/3. ab. caecus, Geoff., " Fourc. Ent. Paris.," ii., pp. 245 (1785). Immaculata, 

 Fuchs, "Jahrb. Nass. Ver. Naturk.," xliv., pp. 211 et seq. (1891); Riihl, " Pal. 

 Gross-Schmett.," pp. 196, 740 (1895) ; Tutt, " Brit. Butts.," pp. 196-7 (1896) ; 

 Wheeler, "Butts. Switz.," p. 46 (1903)/ — P. caecus. L' Argus verte, ou 1' Argus 

 aveugle. Long. 6 lig. Larg. 14 lig. P. alis rotundatis integerrimis, 

 subtus viridibus immaculatis (Geoffroy). — Hindwings beneath uniform green, 

 quite spotless ; two c? s from here, one inclining to a yellowish tint above. 

 The observation that this almost universally distributed species varies in 

 the number of white dots on the underside of the hindwings, is not new. Of 

 thirteen examples in my collection — one c? from Oberursel, eleven <? s and 5 s from 

 here (Nassau), and one ? from Bodo — I find only four, two <? s and two ? s, which 

 have a completely developed row of white dots beyond the middle of the hindwings. 

 In one ? (from Nassau) there are seven, the maximum number possible, viz., a dot 

 in each cell ; the seven dots vary in shape and size — the first, below the costa, is 



