318 BRITISH LEPIDOPTERA. 



(1881) ; Snellen, " De Vlinders," p. 999 (1882) ; Peyer., " Cat. Lep. Als.," 2nd Ed., 

 ii., p. 165 (1882); Sorhagen, " Die Kleinschmett. Brandbg.," p. 308 (1886) ; Meyr.. 

 Handbook." etc., p. 723 (1895J. Salidcorella, Dbdy., "Cat.," p. 36 (1866); 

 Porritt, "List. Yorks. Lepidop.," p. 171 (1886). 



ORIGINAL DESCRIPTION. Ntpticitla salicia, n. sp. Alls anticis f uscis, 

 dilute lufceo parum irroratis, postice saturatioribus et violaceo-tinctis, 

 maculis duabus dilute luteis pone medium, fasciam obsoletam obliquam 

 formantibus ; capillis ferrugineis. Exp. al. 2*-3 lin. Head and face 

 reddish-yellow. Palpi whitish. Antennae fuscous, basal joint whitish. 

 Anterior wings fuscous, slightly irrorated with pale luteous, posteriorly 

 darker, and with a faint violet tinge ; beyond the middle are two ill- 

 defined, pale luteous spots, forming an indistinct oblique fascia ; the 

 costal spot is anterior to the dorsal spot ; cilia pale luteous. Posterior 

 wings pale grey, with pale grey cilia. Appears in May and August. 

 The yellowish larva makes small tortuous mines, resembling blotches, 

 in the leaves of sallows, in autumn and in July (Stainton, Insecta 

 Britannica, p. 302). 



IMAGO. Head reddish-yellow. Anterior wings 5-6 mm. ; fuscous 

 with a yellowish tinge ; apical portion darker, tinged with violet ; an 

 oblique, pale yellowish fascia (sometimes divided into two opposite 

 spots) beyond the centre ; cilia pale yellowish. Posterior wings and 

 cilia pale grey. 



COMPARISON OF N. SALICIS WITH ITS ALLIES. JV. salicis belongs 

 to that section of the genus in which the anterior wings bear a 

 single powdery pale fascia. It resembles, in this, N. -flodactdla, but 

 the fascia is rather nearer the base, is more obliquely placed, and more 

 slender. The apex of the wing is also darker, and the basal half is 

 less coarsely scaled, and therefore seems smoother, and it never appears 

 yellowish ; besides, the legs are grey in this species, whereas in X. 

 jlnslactclla they are pale ochreous (Stainton). 



EGG-LAYING. The egg is deposited on the undersurface of the 

 rough leaves of Salh- cinerea and S. caprea, near a rib, and almost 

 concealed in the down that covers the underside of the leaf. 



MINE. The mine commences with a short visceriform track, soon 

 becomes more open, and ends in a complete blotch. The excrement 

 in the early part of the mine is reddish-brown, in the blotch 

 dark grey, forming a rather broad continuous streak (Stainton). 

 Wood observes that the larva feeds on almost every species of Sali.i', 

 and the mines vary according to the physical differences between the 

 leaves of the various plants. In the small crumpled leaf of <S. aitrita, 

 the mine is condensed into a vermiform gallery ; in the large leaf of 

 S. cajn-ca, the gallery, almost filled with frass, is either fairly straight 

 (following the line of a rib), or more or less contorted, or, on the other 

 hand, it may dilate towards its termination into a blotch ; in the 

 smooth-leaved S. alba and S. russelliana, it is invariably a blotch. (The 

 mine in .S'. alba may possibly be that of N. riiiiincticola). Nolcken notes 

 a great similarity between the mines of X. solids and ^V. myrtilleUa, 

 On " Wollweiden " the former makes only a small blotch of pale yellowish 

 colour, the windings raised somewhat above the surface of the leaf, on 

 other species of willow (so far as can be observed from dried leaves), 

 the skin is not raised, and the mine is more greenish in tint. These 

 differences are due to the dissimilar character of the leaves. The 

 mode of deposition of the frass appears just as in the preceding species 

 (N. myrtilleUa). Sometimes the mine forms a fine thread on the 



