See 
AND THEIR TRANSFORMATIONS. 11] 
DESCRIPTION OF PLATE XXXV. 
Insects.—Fig. 1. Polyommatus Eros. 2. Showing the under side. 
9 Fig. 3. Polyommatus Dorylas. 4. The female. 5. Showing the under side. 
Prants.—Figs. 6 and 7, Hippocrepis comosa (the horse-shoe Vetch.) 
T have not met with any British specimens of either of these species, those marked Dorylas in many collections being merely varieties of 
Adonis ; and I have seen small varieties of Argus marked Eros, It seems doubtful whether the true species has ever been found in this country ; 
I therefore give the figures of Hitbner to enable collectors to compare specimens, which they may suppose to be either of these species. H,.N.H. 

SPECIES 10.—POLYOMMATUS EROS. THE PALE BLUE BUTTERFLY. 
Plate xxxv. fig. 1—2. 
Synonymes.—Lycena Eros, Ochsenheimer, 4, p. 26. Argus Eros, Boisduval, Icones Hist, Lep. pl. 14, fig. 4—6. 
Polyommatus Eros, Jermyn, Steph. Ill. Haust. 1, p. 93. Wood, Papilio Tithonus, Hiibner, Pap. pl. 108, fig. 555, 556, ¢. 
Ind. Ent. t. 3, fig. 70, 3, 9. Haworth in Ent. Trans. 1. 334. 
The expansion of the wings of this doubtful British species is rather less than an inch and a quarter. The 
upper surface of the wings in the males is of a pale azurine blue, with a silvery or greenish tinge, which is not 
found in the allied species, P. Dorylas. The fringe is white, and separated from the ground colour of the wings 
by a black border, which is broader than in Dorylas, and which extends slightly upwards along the tips of the 
veins, especially in the under wings, which thus assume the appearance of having the margin spotted with black. 
The under side of the wings has considerable resemblance with Alexis in the ground colour and arrangement 
of the ocelli and markings; the ground colour being brownish grey, with the base saturated with greenish blue. 
The fringe is separated from the ground colour by a slender black edge, preceded by marginal lunules of pale 
yellowish orange, within each of which is a black arch, and on the opposite side a small black spot. These 
fulvous markings are more indistinct on the upper wings ; their black anterior part is, on the contrary, more 
strongly marked. Between the mark at the extremity of the discoidal cell of the fore wings (which is nearly the 
same as in Alexis) and the fulvous lunules, is a range of ocellated spots ; the discoidal spot is preceded by an 
ocellated spot (Boisduval figures two such basal spots) in the fore wings, and in the hind wings by a row of four 
(or three) similar ocelli, placed upon the greenish part of the base, as in Alexis. The under side of the breast 
and legs are of a greenish grey, and that of the abdomen white ; the thorax and the under side of the abdomen 
are blue. 
The female differs from the male almost in the same manner as in Alexis ; some specimens being entirely 
brown, and others saturated with blue from the base to beyond the middle ; some again have only some blue 
‘ ; . . : > wi is rather black 
atoms at the base, and along the inner edge of the fore wings. The ground colour of the wings is rather 
than brown, with a central black lunule. The extremity of the hind wings is ordinarily marked with a row of 
lunules, fulvous within, black in the middle, and edged externally with white. The under side scarcely differs 
from that of the male, except that the fulvous spots are rather brighter coloured. 
= aC . 8 
On the Continent this is a rare species, being found on the Alps of Valois, Tyrol, and France ; Mount Cenis 
and the environs of Digne and of Gap have been recorded as its localities. It is therefore doubtful whether 
a i x < Beek Le nate : r 7 
Messrs. Haworth and Stephens, who have introduced this species into the English catalogues, may not have 
mistaken some pale variety of Alexis for it. From that species it is at once known by the peculiar pale upper 
surface of the wings of the male, with a dark border ; and from the female, by the much darker upper surface. 
Q2 
