PLATE XXVIII. 
No. 1.—The Silver-studded Blue Butterfly (Polyom- No. 5.—The Chrysalis of the Silver-studded Blue 
matus Egon). Butterfly. 
No. 2.—The Female of the Silver-studded Blue No. 6.—The Brown Argus Butterfly (Polyommatus 
Butterfly. Agestis). 
No. 3.—The Silver-studded Blue Butterfly, showing No. 7.—The Female of the Brown Argus Butterfly. 
the Under side. No. 8.—The Brown Argus Butterfly, showing the 
No. 4,—The Caterpillar of the Silver-studded Blue Under side. 
Butterfly. 
THE insects represented in this Plate will complete the illustration of the genus Polyommatus, 
which has occupied the three preceding ones. 
Polyommatus Afgon (the Silver-studded Blue Butterfly, Nos. 1 to 5). This pretty species is 
at once distinguished by the metallic spots which form part of the markings of the under side 
of the hind wings, and also by the dark blackish border to the blue on the upper surface of the 
wings of the male. The female (No. 2) is rather larger than the male, and of a warm coppery 
brown, all four wings having a bordering of small orange marks of a somewhat triangular form. 
The under side of the wings, which is very nearly alike in both sexes, is shown at No. 3. The 
Caterpillar (No. 4) feeds upon Broom, Saintfoin, and several species of Trifolium. The Chrysalis 
(No. 5) is at first of a bright green colour, but as the shell hardens it becomes brown. The 
perfect insect is found on marshy commons or damp fields in July. It is very rarely found in 
the North of England, but in the Southern counties it is not uncommon, especially in certain 
localities which appear suitable to its habits, particularly in the vicinity of Sarum in Wiltshire, 
in some places in Nottinghamshire, and Coleshill Heath, Worcestershire. It is found, though 
rather sparingly, in the metropolitan counties. 
There are several rather remarkable varieties of this pretty species. One is a brown variety 
of the male—the upper surface of both pairs of wings being of a pale tawny colour. Another 
variety, formerly considered a separate species under the name of P. Alcippe, has the wings very 
narrow, and the pale blue is bordered by a much darker and more distinct band at the edges. 
A third variety has the two rows of dots on the under surface running into each other, and 
forming a series of dark stripes which give it a very distinct appearance. This species was 
named P. maritima, as having been found in the salt marshes near Holt, in Norfolk. There 
are several other varieties of this pretty species, but of a less remarkable kind. 
Polyommatus Agestis (the Brown Argus Butterfly, Nos. 6 to 8). This very distinct species 
has all the characteristics of the “Blues” except the blue colour of the upper surface of the 
wings in the males, both sexes of P. Agestis being of the same dark brown hue as the females of 
most of the other species. The male (No. 6) is of a darker and brighter brown than the female. 
The female (No. 7) is sometimes rather larger than the male, and has the borders of orange 
