216 BKITISH LEPIDOPTERA. 



Fliigelspitze, welche bei unserer Spezies niemals rein violetfc, sondern 

 vielmehr purpurgliinzend erscheint ; bisweilen fast rein purpurfarben. 

 Die Franzen grau, wie bei vorhergehender Spezies " (Frey, Die Tincen 

 und Pterophoren der Sckweiz, pp. 875-376). 



IMAGO. Head black. Anterior wings 4-5 mm. in expanse ; dull 

 bronzy in colour, with the apex of a rather dull purple hue, which 

 shades gradually into the greyish-purple cilia. Posterior wings and 

 cilia pale grey. 



COMPARISON OF N. TILLE WITH ITS ALLIES. X. tiliae belongs to 

 the unicolorous section of the genus, and from its black head, can only 

 be confounded with N. atricapitella, N. minusculella, X. lonicerantm, 

 and the black-headed specimens of A*, anomalella. From N. atricapi- 

 tella it may be most easily separated by its much smaller size, and by 

 the less glossy anterior wings. From N. minusculdla it may be dis- 

 tinguished by the anterior wings being broader and of a duller colour. 

 N. tiliae very closely resembles A T . lonicerantm, but the anterior wings 

 are scarcely so dull as in the last-named species. From N. aiwmalclla, 

 X. tiliae is best distinguished by the purple apex of the anterior wings 

 shading gradually paler into the cilia ; in X. anomalella the purple 

 apex is quite sharply defined against the grey cilia. Besides, X. ano- 

 malella has the wings more glossy, and generally with a faint indica- 

 tion of a pale fascia beyond the middle (Stainton). 



EGO-LAYING. The egg is laid on the undersurface of a leaf of the 

 lime tree, against a rib. 



MINE. The mine is contorted and slender, and does not occupy 

 at its commencement the whole thickness of the parenchyma ; the 

 excrement forms a slender, blackish line for a considerable distance, 

 and sometimes for the whole length of the mine, but not infrequently, 

 in the second half of the mine, it occupies nearly the whole width of 

 it, being deposited in a series of curves (much as in the mines of 

 X. viscerella). Sometimes the mine is entirely of the latter form, and 

 then it is generally much contorted. In some mines the excrement 

 retains its linear form throughout, so that one would almost feel 

 inclined to assume that we had here two distinct species, but some 

 mines are decidedly half of one form and half of the other (Stainton). 

 Previously these two forms of mine had been . noticed as probably 

 belonging to two different species of Xepticula (Ent. Ann., 1859, p. 163). 

 Hodgkinson reports as many as eight larvae in a single leaf, near 

 Stoneyhurst. Frey writes : " Die Mine hat ein ganz eigenthiimliches 

 Ansehen. Sie ist sehr stark gekriimmt, indem die Windungen unregel- 

 massig und ganz dicht an einander gedriingt verlaufen. Der Anfang 

 derselben ist sehr fein und von der zarten braunenKothlinieganz erfiillt. 

 Weiter abwiirts wird der Gang breiter und, indem dieKothlinieeinfach 

 bleibt, erscheinen die Bander jenes leer und weiss. Erst gegen das 

 untere Ende liegen die Kothmassen wie bei X. anomalella. Es 

 kommen zuweilen 8-4 Gange in einem grosseren Blatte vor " (Linn. 

 Ent., xi., p. 882). 



LARVA. Length 2 lines. Pale amber-yellow, with the dorsal 

 vessel rather dark green ; head pale brown, with two dark brown 

 lobes showing through the skin of the second segment (Stainton). 

 Frey writes : " Die blasser gelbe, gegen 2'" grosse Raupe minirt im 

 September und Anfang Oktober die Blatter von Lindenbiischen 

 (jTiYm i/rantli flora) in unseren Gebirgswiildern ; namentlich an etwas 



