Volume 10, Plate XXXII / Entomology (Insects)

Large Blue, Alcon Blue & Chalk-Hill Blue Butterflies

Polyommatus Arion, P. Alcon & P. Corydon

1. Large Blue Butterfly. Considerably larger than the other blues, sometimes an inch and a half across, it is pale violet-blue with a broad dusky border, the male bearing a group of black spots on the fore wings, the female on all. Beneath it is ash-coloured with bands of eyes and lunules; extremely rare in Britain, it has been taken on Dover Cliffs and near Bath.
2. Alcon Blue Butterfly. The male is violet-blue with a rather wide brown border and a dark crescent on the fore wings, the female dusky brown tinged with blue toward the body. Beneath, both are greyish with white-bordered crescents and rows of black and triangular spots; found only once in this country, its figure was necessarily taken from a foreign specimen, and its British claim remains doubtful.
3. Chalk-Hill Blue Butterfly. One of the larger blues, spanning seventeen or eighteen lines, the male is light silvery blue with a black hind band, the female brown with a pale central spot. Beneath, the hind wings bear two curved bands of eyes and orange-crowned marginal spots; restricted yet locally profuse, it haunts chalky districts and was named from hills between Dartford and Darenth Wood.