DIMORPHA VERSICOLORA. 237 



Rott., "Naturf.," viii., p. 102 (1776); Hb., "Eur. Schmett.," figs. 1, 2 (arc. 1800); 

 "Tent.," p. 1 (1806). Versicolor, Linn., "Faun. Suec," ed. 2, p. 294 (1761) ; 

 Scheven, " Naturf.," xiv., p. 66, pi. iii., figs. 1 — 5 (1780) ; Schrk., " Faun. Boica," 

 ii., r, p, 245 (1801); 2, p. 150 (1802); Latr., "Hist. Nat.," xiv., p. 181 (1805); 

 Oken, "Lehrb. Zool.," i., p. 715 (1815) ; Sam., " Ent. Comp.," p. 247 (1819); 

 Meig., "Eur. Schmett.," ii., p. 153 (1830) ; Stephs., "List. Br. An. Br. Mus.," v., 

 p. 44 (1850); Wood, " Ind. Ent.," p. 21, fig. 38 (1839); Humph, and West., 

 " Brit. Moths," p. 79 (1841) ; Humph., " Gen. Brit. Moths," p. 20 (i860) ; Newm., 

 " Brit. Moths," p. 47 (1869) ; Buck., " Larvae, &c," iii., p. 60, pi. xxi., fig. 3 (1889); 

 Auriv., "Nord. Fjar.," p. 65 (1889) ; Kirby, " Cat.," p. 722 (1892) ; " Handbk," 

 iv., p. 67 (1897); Tutt, '-Brit. Moths," p. 47 (1896). Versicolorus, Haw, " Lep. 

 Brit.," i., p. 80 (1803). Visicolora, Leach, " Edin. Encycl.," ix., p. 132 (1815). 



Original description. — Phalaena Bombyx versicolora, elinguis, 

 alis reversis griseis; strigis nigro-albis, fronte thoracis albo. Gadd, 

 Satag., 82, Phal. alis lineis albis et nigris undatis. Roes., Ins., 

 app. 39, f. 3. Wilk., Pap., 45, t. 1, a. 1. Habitat in Europa 

 (Linne, Sys. Nat., xth ed., p. 499). To this description Linne 

 adds : " Speciosa, magna. Thorax antice albus linea nigra ter- 

 minatus. Ala? superioris angulus posticus maculis 3 albis ; in- 

 feriors macula diaphana ad apicem" (Sys. Nat., xiith ed., p. 817). 



Imago. — 49mm. — 87 -5mm. in expanse. $. Collar whitish, 

 thorax orange-brown mixed with grey scales, abdomen orange- 

 brown. Anterior wings deep orange-brown with two brown-black 

 transverse lines, the basal one curved, edged internally (nearest 

 base) with whitish, or whitish-ochreous, the outer one deeply angulated 

 below its centre, edged externally with whitish ; a pale subterminal 

 line, made of large arches, including the pale portions of the 

 nervures towards the outer margin, and ending in three silvery- 

 white spots (often united) near the apex; basal tuft greyish-white; 

 the discal area, sometimes suffused with grey, contains a dark 

 <-shaped discal spot with point towards base. Posterior wings 

 orange or orange-brown, with a single, median, transverse black 

 line (continuation of the angulated one on forewing), an ill-defined 

 discal spot, a transverse series of dark spots, the outer edge of 

 which is continuous with the subterminal of forevvings, and ends 

 at apex in two silvery-white or ochreous spots. $ . Paler; the 

 anterior wings with the pale areas much enlarged, the <-shaped 

 mark often obsolete; the posterior wings white instead of orange- 

 brown. Fringes practically obsolete in both sexes. 



Sexual dimorphism. — The male is smaller, darker in colour, 

 much more active than the female, which is paler, less brown, 

 with a much larger and heavier abdomen. The three apical spots 

 remain white in the 6* s, whilst all the other pale forewing markings that 

 are whitish in the 2 s tend in varying degrees to become reduced in 

 size or entirely suffused with pale brown in the $ s. (This is not 

 invariably the case, as in some $ s the pure white is maintained 

 and its effect heightened by the deeper and richer, normal, male 

 ground colour). The hindwings exhibit still greater differences, 

 those of the $ s only showing two white (or ochreous) spots 

 at the apical angle, and even these are sometimes strongly suf- 

 fused by the yellow-brown which, in this sex, usually replaces the 

 white areas of the 2 hindwing. The pale markings of the 

 hindwings of the $ s are so enlarged (perhaps it would be more 

 correct to say the brown markings are so reduced) that one might 

 call the ground colour white, whilst that of the forewings is pale 



