258 BRITISH LEPIDOPTEEA. 



with darker antennae (?), sutures and mouth-parts. The legs are con- 

 spicuous and larger than is usual in the genus." 



COMPAEISON OP THE MINE OF N. ULMIVORA WITH THOSE OF N. mar- 

 ginicolella and N. viscERELLA. — The occupied mine can be at once 

 told from that of N. marginicolella, since the larva of the latter is 

 yellow, that of N. idmivora green, but it is less easily told from that 

 of N. viscerello, which also has a green larva. The mine of the 

 latter, however, is so closely wound that scarcely any uneaten leaf- 

 substance is left between the curves, and the mine obtains a blister- 

 like appearance. N. viscerella, too, lays its egg on the upperside of 

 a leaf, whilst that of N. idmivora is laid on the underside, and 

 although the mine of the latter is frequently strongly twisted, yet the 

 curves are never so close as to leave no leaf-substance between them 

 (Nolcken). 



Cocoon. — The cocoons average 2*1 mm. in length and 1-3 mm. in 

 width. The basal surface is quite flattened, the upper surface domed, 

 springing almost directly from the edge (as there is scarcely a trace of 

 a defined basal rim) , round which, however, bunches of silken fibres 

 stretch out at almost regular intervals, and have undoubtedly served 

 to keep the cocoon in position ; in outline the cocoon is almost a perfect 

 oval. It is red-brown in colour, with a somewhat smooth surface, 

 but rather plentifully surrounded by ochreous or whitish flossy silk 

 fibres, which are especially abundant on the upper surface. [Described 

 June 14th, 1898, under a two-thirds lens, from cocoons sent by Dr. Wood.] 



Food-plant. — Ulmus campestris. 



Time of appearance. — The species is probably double-brooded, but 

 is later in appearing than N. marginicolella, and, probably, N. visce- 

 rella. McLachlan bred it in June, 1861, from larvae found the pre- 

 ceding autumn, at West Wickham. Sang notes it on June 7th, 

 1868, at Darlington, and Tompkins as taken on palings near Clap- 

 ham Common, on August 30th, 1860. Sang found larvae on October 

 17th, 1871, August 13th, and September 16th, 1873, September 14th, 

 1874, at Darlington, and September 24th, 1874, at West Wickham. 

 It is very uncertain in its appearance, some years appearing in great 

 abundance. This happened at Cambridge in the autumn of 1882. 

 Stainton records the capture of larvae, three being " nude on a fence," 

 on October 2nd, 1860, between Norwood Station and West Wickham 

 Wood. Threlfall bred imagines in May, from larvae obtained 

 September 30th, 1876, at Witherslack. Nolcken found mines on 

 September 19th, 1865, almost all unoccupied, at Umbaid, nr. Pichten- 

 dahl, and again from August 7th-llth, 1866, when only five out of 

 eleven were occupied ; on September 3rd, 1871, more were occupied, 

 but still so many were empty that it seemed probable from the early 

 maturity of the autumn larvae that there is only one brood in the year. 



Localities. — Cambridge : Cambridge, uncertain, sometimes abundant 

 (Warren). Dorset: Bloxworth (Cambridge). Durham: Darlington (Sang). 

 Hereford: Tarrington (Wood). Kent: West Wickham (McLachlan). Lanca- 

 shire : Dutton (Hodgkinson), Grange (Threlfall). Norfolk : K. Lynn, in elm 

 hedges, periodic in appearance (Atmore). Surrey: Clapham Common (Tompkins). 

 Sussex : Bramber, in elm hedges, local ("Fletcher). Westmorland : Witherslack 

 (Threlfall). 



Distribution. — Belgium : nr. Brussels (Fologne). France : St. 

 Martin Lantosque (Milliere). Germany : Frankfort-on-the-Main 

 (Frey), Berlin, Hamburg, Brunswick, Breslau, (Sorhagen), Silesia 



