POLYOMMATUS ICARUS. 193 



wards, i.e., in about half the length of time as observed in England. 

 Wolfe first recorded {Tutt's British Butterflies, p. 443) the habit 

 that P. icarus occasionally has of laying its eggs upon objects adjacent 

 to the foodplant, as well as on the latter itself, and Harrison remarks 

 (Ent. Piec, xvii., p. 24) on the great variety of plants on which the 

 eggs were found in nature during August, 1904, in Fife; the greater 

 number, he says, are laid upon Lotus corniculatus and Trifolium 

 pratense, but six were found laid on Plantago lanceolata, four or five on 

 Achillea millefolium, and one on Pimpinella saarifraga, not suggesting, 

 of course, that all these were necessarily foodplants. 



Ovum. — The egg of P. icarus varies in size, the diameter from 

 0'48mra. to about 0-54mm., and the height from 023mm. to 025mm. 

 The sides are not very upright, but rounded so as to make the flat top 

 rather under 0*4 mm. across. The flat top does not give the same 

 impression of being a very separate and specially levelled area that 

 the eggs of Agriades cor id on and A. thetis do, which I have expressed 

 by saying they looked as if treated by a steam-roller. Quite why this 

 is, is not very evident, the pillars or knobs at the angles of the mesh- 

 work are wanting on top, but do not begin at the margin quite as in 

 A. coridon: perhaps the chief reason is the large size and irregularity 

 of the cells of the network ; the egg of A. thetis, which I describe as 

 having the cells somewhat irregular, has them, however, quite orderly 

 in comparison, and the cells are 0-04mm. across, whilst, in P. icarus, a 

 smaller egg, they are about 0*045mm., but vary much. They are 

 triangular, quadrangular, and pentagonal with very varying shapes. 

 The micropylar area is about O7omm. across. There are about six 

 cells in this width, but they are rather irregular in form and position, 

 and the central cells do not form at all a regular rosette. The knobs 

 on the tops of the columns of the white coating are well raised but 

 not large ; the cells are, as usual, formed by white ribs hanging in 

 catenary curves from knob to knob, and, though a little more regular 

 on the sides than on the top, present various forms nearly as frequently 

 as the more typical triangles arranged hexagonally (Chapman). Of 

 the ordinary echinoid appearance of most Lycaenid eggs ; about 

 •5mm. in diameter ; delicate green in colour, covered with small white 

 elevations, which are joined by slender, shiny, white curved ribs. The 

 outline is that of a flattened disc, rounded towards the base, and 

 slightly hollowed in the centre of the upper surface. The curved area 

 of the base of the egg is covered with similar, but smaller and finer, 

 reticulation ; the upper surface of the egg slopes very gradually to the 

 micropyle, the reticulation being almost identical with that of the 

 sides ; the central micropylar depression, almost smooth in appearance, 

 and composed of much smaller cells, is very conspicuous, and greenish 

 in colour (Tutt, June 6th, 1893). Circular in outline, rather flat, 

 just -5mm. in width, less than half that measurement in height ; the 

 shell dull, covered on the sides and just over the edge of the upper 

 surface with raised reticulation, having projecting knobs at the knots ; 

 this reticulation becomes finer and less prominent on the upper sur- 

 face, which has a central depressed spot ; this spot is green, while the 

 general ground colour is greenish-white, and the reticulation glistening 

 white (Hellins). The egg is figured by Clark [Ent. Pcec, xii., pi. xi., 

 fig. 6 (fig. 4 by error)] . 



Habits of Larva. — The young larva makes its escape from the egg 



