294 BRITISH LEPIDOPTERA. 



aber an den Enclen etwas verdickt. Die Franzen der Vorderfliigel, 

 sowie die Hinterfliigel sind licht gelblichgrau. Auf der Unterseite sind 

 die Vorderfliigel fein schuppig, gelbgrau mit rothlichgelbem oder 

 violettem Schimmer, die Franzen und Hinterfliigel wie auf der 

 Oberseifce. . . . Alsich Anfang August nach der Eaupe suchte, kam ich 

 leider zu spat, da ich an den Birkenblattern nur bereits verlassene 

 Minen antraf. Diese Minen, die ich mit grosser Wahrscheinlich- 

 keit als hierher gehorig betrachte, sind von bedeutender Lange, 

 beginnen auf der Oberseite des Blattes liber dem unten festgeleimten 

 Ei in einer feinen Linie, die gewohnlich, dem Laufe einer Rippe folgend, 

 sich rasch verbreitert und mit einem grossen, unregelmassig ovalen, 

 hellgriinen, exkrementlosen Fleck endet. Im Anfang ist die Mine 

 vollstandig mit Excrementen erfiillt, weiterhin bilden dieselben in der 

 Mitte des Ganges eine schmale braune Linie. Aehnliche Minen 

 bemerkte ich auch auf Birkengestrauch in der Nahe von Fogstuen 

 auf dem Dovre, aber auch diese waren verlassen (Wocke, " Reise nach 

 Finmarken," Stett. Knt. Zeit., 1862, pp. 251-253). 



Imago. — Head reddish. Anterior wings 6-7 mm. ; yellowish-grey, 

 shiny, with a reddish tinge ; apex slightly violet ; an oblique, rather 

 broad, yellowish-white, transverse fascia, beyond the middle : cilia 

 pale yellowish-grey, darker at base. Posterior wings and cilia pale 

 yellowish-grey. 



Comparison of N. lapponica with N. sorbi. — N. lapponica is 

 closely allied to N. sorbi, but has the fascia less oblique, more yellow, 

 and generally broader (Threlfall). 



Egg-laying. — The eggs are laid on the upper side of a leaf (Wocke). 



Mine. — The larva makes a long gallery in a birch leaf, and is 

 markedly angular (never contorted), going off sharply from one point 

 to another. The commencement of the mine is straight, and very fine. 

 In the first portion of the mine (corresponding to the first two skins of 

 the larva), the frass is of the typical concretionary character and com- 

 pletely fills the mine ; in the second part it is coiled, but rather 

 obscurely, owing to a tendency that the pellets still have to run 

 together ; in the third portion the frass, which has hitherto filled the 

 mine, is suddenly collected into the centre, leaving a wide margin on 

 each side, and, at the same time, the colour, which up to this point 

 has been green, changes to black (Wood). 



Larva. — The larva is yellow in colour, the cephalic ganglia brown 

 and distinct, the head black. No trace of the ventral cord is discover- 

 able whilst the larva remains in situ, but it becomes visible when the 

 larva is removed from its mine, and is faint brown in colour. The 

 larva mines with the back up and shows distinctly the brown cephalic 

 ganglia (Wood). Threlfall notes the larva as "greenish-yellow" in 

 colour. 



Comparison of the mines and larvae of N. lapponica and N. confu- 

 sella. — The mines of both are long galleries of moderate width, whose 

 usual course is to follow a rib for some distance, and then to turn off 

 at a tangent till another is reached, which, in its turn, is pursued ; 

 but whether the ribs be taken as a guide or not, the mine is never con- 

 torted, and this holds good even with their very commencement, 

 which, beginning in a delicate and hairlike manner, stretches straight 

 away at once from the site of the egg. So far, and in a general view, 

 the mines are precisely alike, but in the two portions which answer to 



