474 BRITISH LEPIDOPTERA. 



" white-grey mixed with weak rust-yellow and with weaker markings," 

 represents another colour tint of this obsoletely-marked form. That 

 Glaser, in 1863, redescribed tremulae as "the small light aberration of 

 greenish-white ground colour and with weaker markings" (see 

 anted., iii., p. 471), points somewhat to the fact that, apart from 

 the mere tint of the ground colour, he probably intended to include 

 in his ab. tremulae all the pale obsoletely-marked aberrations of this 

 species kno'vn to him, although he does not say so. It appears to us 

 that the ab. tremulae, Bkh., ab. tremulae, Glas., and ab. subfiava, 

 Gillm., are separable elements of our more comprehensive ab. pallida. 



[Page 469.] Amorpha fiopuli ab. decorata, Schultz, "Berl. Ent. Zeits.," 

 xlvii., p. 288 (1902). — Maculis alarum arrticarum ferrugineis aeque ac in basi posticarum. 

 Auffalend dadurch, dass rostrote Flecken (von der Farbung des Hinterfliigel- 

 Wurzelfeldes) auf den Vorderfliigeln sich deutlich von der lichtgrauen Grundfarbung 

 abheben. Upperside : Forewings of a light ashy-grey (not red-grey) ground 

 colour, with a broad dark grey median area, which is shat ply marked off from the 

 paler basal area .... In the median area of both forewings along the 

 inner margin, and reaching to nervure 3 is a patch oi rust-red colour, like that of 

 the basal patch of the hindwings, which, towards the base and outer margin, 

 stands out in stronger relief than in the intermediate portion of the wings. Hind- 

 wings grey, with a broad rust-red blotch at the base, with a distinct dark wavy 

 line interrupted by the pale nervures. Thorax, abdomen and antennae grey. 

 From Hungary. The example mentioned by Treitschke (Die Schmett., x., 

 p. 141) as being found by Kollar, and which had a rust-red marking on one 

 forewing, appears to be an asymmetrical transition to the new aberration (Schultz). 



[Page 482.] Development of thk markings of the larva 

 of Amorpha populi. — First ins tar : The newly-emerged larvae are 

 6.5mm. in length, without markings, of a light greenish-white hue, 

 the large head and long caudal horn being of the same colour, 

 the posterior boundary of the segments appearing as a light shining 

 ring (pi. vi., fig. 55). The characteristic markings of the genus 

 appear on the following day without the occurrence of any moult ; 

 7 oblique white stripes arise from near the dorsal line, and extend 

 along the sides in a direction parallel to that of the horn. On the 

 front three segments they are represented only by three small white 

 spots (fig. 56) ; the larva likewise possesses a marking, of which 

 the adult species of the genus retain only a trace, viz., a well- 

 developed, pure white, subdorsal line, which is crossed by the six 

 anterior oblique stripes, and, uniting with the upper part of the 

 7th, extends to the caudal horn. The larva moults after five days. 

 Second instar : The larvae are now i'4cm. in length. Only unim- 

 portant changes of marking are connected therewith. The subdorsal 

 lines lose much in thickness and definition, and the first and last 

 of the oblique stripes become considerably broader than the inter- 

 mediate ones (fig. 57). The green ground colour, and also the 

 stripes, acquire a yellowish hue. On the other hand there occur 

 changes in form. The head, which was at first rounded, becomes 

 of the characteristic triangular shape, with the apex upwards, common 

 to all the species of the genus, and, at the same time, acquires two 

 white lines which unite above at the apex of the angle ; the 

 shagreening of the skin now also takes place, and the red spot at the 

 base of the horn is formed. There appears to be at this stage a 

 general tendency for the suffusion of red, the thoracic legs also 

 becoming of this colour. The second moult occurs after 6 or 8 days. 

 Third instar : The marking only changes to the extent of the sub- 



