2J00 BRITISH LEPIDOPTERA. 



N. flodactella and to N. salieis, but the fascia is broader, perfectly 

 straight, and not so yellowish ; the anterior wings are also rather 

 more elongate, and the basal portion is of an uniform dull grey. In 

 the Nat. Hist, of the Tincina, vol. i., p. 108, in the description of 

 N. floslactella, the present species is thus alluded to: " A probable 

 third species in this section diners by the anterior wings being longer, 

 and the pale fascia more nearly perpendicular." It is satisfactory to 

 find that a species thus dimly indicated by the imago obtains such 

 decided corroboration by the discovery of the larva (Stainton, Ent. 

 Annual, 1861, p. 91). 



Imago. — Head ochreous. Anterior wings 6-7 mm. ; basal area 

 dull grey ; a broad, straight, pale yellowish, transverse fascia beyond 

 the middle ; apical area greyish-fuscous. Posterior wings and cilia 

 grey. 



Egg-laying. — The egg is laid on the underside of a leaf of Pyrus 

 aucuparia, sometimes near, at other times well away from a rib. 



Mine. — The mine blisters very much the upper side of the leaf, 

 and is thus conspicuous, although it is practically invisible on the 

 undersurface. It forms at first a very slender gallery about half an 

 inch in length, with but few windings, the rather pale frass occupying 

 most of the mine, although there is a slender margin on either side. 

 The mine then forms a large blotch from 10-15 mm. in length, and 

 from 8-12 mm. in width, in which the frass appears in some cases to 

 show the path of the larva, in other cases to be widely scattered, 

 probably due to the larva crossing and recrossing its earlier paths 

 when in the mine. The blotch often absorbs the first or gallery part 

 of the mine, and in some cases two and three larvae finish up by 

 forming a common blotch, in one case four larvae have blotched the 

 whole of one side of a leaflet. A single leaflet may contain as many 

 as seven mines. Nolcken notes that the first part of the mine con- 

 sists of a very slender gallery extended in gentle curves, the frass-line 

 forming at first a rather strong, often interrupted, thread, which soon 

 becomes granular, and broader, but never wholly fills the mine, 

 appearing very faint, though edged by pale borders. The second 

 portion of the mine suddenly widens into a large, brownish blotch, 

 varying in shape, the outline, however, always consisting of sections 

 of a circle convex exteriorly. The exit is on the upper side of the 

 leaf. Sorhagen describes it as "fine at first, following the margin of 

 the leaf, then, broadening, it ends in a large round blotch with the 

 frass in the centre." 



Larva. — The full-fed larva is from 4-5 mm. long. The body is of 

 a pale greenish colour, almost transparent, rather more distinctly 

 coloured on the dorsum than the venter. The head is pale brown, 

 retractile within the prothorax, which is much smaller than the meso- 

 and meta-thorax. The thoracic segments glassy or watery-looking, 

 scarcely tinged with green. The prolegs specially well developed on 

 abdominal segments 1-5. The scattered hairs transparent, glass-like. 

 There is a distinct medio-dorsal series of purplish linear spots beneath 

 the skin of the pro-, meso- and meta-thorax. A medio-ventral series of 

 seven narrow diamond-shaped spots run the length of the first seven 

 abdominal segments, the spots themselves placed at the front part of 

 each segment, and each successive pair joined by their back and front 

 parts respectively by a slender purplish medio-ventral line, which 



