KEPTICtfLA LAPPONICA. 295 



the first three skins of the larvae, and which, from their apparent 

 insignificance are apt to be overlooked, most excellent and easily 

 appreciable characters may be gathered. In the case of N. lapponica, 

 the frass completely fills these two portions of the mine, while it is 

 coiled in the second of them, its colour in both is green, thereby 

 offering a striking contrast to the third or main portion of the mine, 

 in which the frass is black, and collected into a narrow thread. On 

 the other hand, the frass in X. confmella is black throughout, there is 

 no coiling in the middle portion, and a free margin borders its track 

 in all three portions, so that the character of the mine is uniform 



from beginning to end The larva of jV. lapponica is yellow, 



with the cephalic ganglia brown and distinct, yet at the same time less 

 conspicuous than the head ; that of N. confusetta is greenish- white, 

 the head very pale brown, the cephalic ganglia dark and distinct, and 

 markedly more conspicuous than the head. The larva of N. lapponica 

 feeds in June, that of X. confmella a little later, in July (Wood). 



COCOON. The cocoons examined (5) average about 2-4 mm. in 

 length and 1-5 mm. in width. They are oval in outline with one 

 end rather broader than its nadir, in fact, it belongs to that shaped 

 cocoon which we have elsewhere designated as almond-shaped. The 

 cocoon, however, is comparatively thick, being considerably domed 

 from rim to apex. It is of a deep reddish- or purplish-brown colour, 

 the silk matted into blackish threads on the surface, and holding 

 pieces of earth and sand, the loose fibres round the rim being united 

 into projecting cables, as it were, by which the cocoon has been attached. 

 The rim is not at all well developed, but is conspicuous from being 

 orange instead of purplish-brown in colour. The empty pupa-case 

 is transparent, shaded somewhat with pale grey, and projects from 

 beneath the rim. [Described July 12th, 1896, under a two-thirds 

 lens, from cocoons sent by Dr. Wood.] The cocoon varies from dark 

 brown to almost black, and is usually placed under the soil (Wood). 



FOOD-PLANT. Betula alba. 



TIME OF APPEARANCE. The species is undoubtedly partially double- 

 brooded, the second brood of imagines being a very small one. Atmore 

 says that it is very early on the wing, imagines having been obtained 

 as early as April 16th, and Wocke obtained imagines at Bossekop 

 (lat. 69 30' N.) from May 28th-June 14th, 1861, flying about Betula 

 alba. Sang notes imagines on June 2nd, 1879, and August 23rd, 

 1873, at High Force ; Shuttleworth records imagines amongst 

 birch, at Witherslack, on May 13th, 1882, whilst Bower found 

 imagines on June 2nd and 3rd, 1891, at Teesdale, and Evans, June 

 6th, 1895, at Boghall, and June 20th, 1895, at Midcalder. Wood 

 records that the larva feeds in June, although occasionally a few 

 mines may be picked up late in autumn ; but Bower found larvae at 

 Teesdale, from August 17th-23rd, 1892, and Threlfall bred the 

 imagines from May 20th-25th, from larvae found between October 1st- 

 20th, 1878, at Grange ; he also notes larvae as early as July 15th, 

 1878, at Witherslack. 



LOCALITIES. DURHAM: High Force (Sang), Teesdale (Bower). EDINBURGH: 

 Boghall (Evans). HEREFORD : Tarrington (Wood). LANCASHIRE : Grange, 

 ? Preston (Threlfall). MIDLOTHIAN: Midcalder (Evans). NORFOLK : King's Lynn, 

 common (Atmore). SUSSEX: Brighton (Vine), Abbott's Wood (Fletcher). 

 WESTMORLAND: Windermere (Hodgkinson), Witherslack (Shuttleworth). YORK- 

 SHIRE : Scarborough (Wilkinson teste Shuttleworth). 



