AND THEIR TR.WSFORMATIONS. .q- 



SPECIES 6.— POLYOiMAJATUS COIIYDON. THE CHALK-HILL HLUE BUTTERFLY. 



I'lati: xxxiii. fig. 4— a. 



SvNoNYMEs — Ilesperia Cori/don, Fabiiciiis ; Iliibiier, Pap. pi. .")9, 

 28(i — 8. Lewin's Pap. pi. 36, figs. 1, 2, 3. Donovan, Brit. Insecls, 

 pi. 231, f. 1, male. Esper. Scliuictt. t. 33, fig. 4. 



Polyommalus Corijdon,'L3.lm\\c ; Stephens; Jcrniyn ; Curtis; 



ings, 



are 



Wood, InJ. E.,1. pi. J,fi,-. 65. Don MM, B.it. Hutt. pi. 32, fi-. 3. 

 Aijriuiles Cori/don, Hiibncr(Verz. bek. Schmett.) 

 Papilio Tiphijs, Esper. Pap. pl. -21, cont. 1 , fig. 4. (Female.) 

 Papilio Caliellii/s, Jiiniyn, 2d l';dit. p. 10'.) (variety). 



This species varies in tlie expansion of its wings from an incli ami a tliir.l to inoro than an iucli :ui(l a li;ilf. 



The male has the upper surface of the wings of a very light silvery blue, with the outor margin and veins dusky ; 



close to the outer margin is a row of black spots, which are almost suffused with dark margin of the fore w 



but are more distinct in the liind pair, two at the anal angle being smaller and close together ; these spots 



more or less annulated with silvery white. Tiie fore wings in this .sex arc of a greyish white on the under sidi 



with five rows of spots, four towards the base in pairs, one larger, and one smaller in e;icli ; then a transverse 



nearly straight row of four spots, of which the inner one is doubled, succeeded by a curved row of four spots 



towards the costa, then two submarginal rows of dots, the inner ones being the largest, forming an interrupted 



bar, and the outer ones rounded and suhocollated ; the tips of the veins, and of the cilia; opposite to the veins are 



marked with dark spots ; the disc of the hind wings is of a pale-greyish brown hue, the base strono-ly saturated 



with greenish blue, each marked with about t^venty blackish ocellated spots, an almost blind white spot at the 



extremity of the discoid.al cell, the space beyond the two middle spots iu the outer curved scries is also white. 



Seven or eight of tlie terminal spots are ocellated, each being preceded by an angular black mark, and a 



small patch of orange colour; the extreme edge of tlie wing is also blackish, and the fringe is white. 



The female differs from the male in having the upper surface of the wings of a brown colour, with a small 



paler spot in the middle of each, that in the fore wings having a black pupil; moreover, there is a submaroinal 



row of ocelli having the pupil black, surrounded by a whitish iris, the upper part iu the hind wings being orange ; 



these ocelli are also sometimes preceded by a row of almost obsolete pale lunules ; in some specimens, however, the 



appearance of these ocellated spots is almost lost ; on the underside the ground colour of all the wings is 



considerably darker than in the m.ales, and the ocelli are much more distinct ; they are, however, similar in their 



number and situation to those of the male, but the fringe is more strongly marked alternately with brown. 



There are a number of varieties in our cabinets resulting from the greater or loss distinctness of the ocelli, 



and the greater suffusion of brown over the wings of the male. One of those varieties having the wings " above, 



brown with a bine disc, and a whitish discoidal dot with a black pupil ; beneath, the posterior wings have a 



discoidal, white, cinctured crescent, with a waved band of seven undulated spots towards tiio hinder margin," 



constitutes the Polyommatus Catethys, of the second edition of Miss Jermyn's Butterfly Collector's Vade mecum. 



The caterpillar is green, with yellow dorsal and lateral lines. It is stated to feed upon the wild thyme. The 



perfect insect appears in .July. It is local in respect to the districts in which it is found, especially frequenting 



chalky places. In such places it is, however, very abundant. From Dover, along the southern coast near 



Shoreham, Newport, in the Isle of Wight, and ne.ar Darenth Wood in Kent, various parts also of Suffolk, 



Oxfordshire, Cambridgeshire, are recorded as its localities. It is also " ver)' abumlant on the iiills above 



Prestbury, near Cheltenham, and near Winchester. A single specimen was also taken a few years ago near 



Knowle, Warwickshire," as we are informed by the Rev. W. T. Bree. 



