8372 Insects. 



blackish. The anterior wings are elongate, narrower and not so 

 rounded as in N. betulicola, more of the same form as in N. glutinosae, 

 which the}' also resemble in their slight glossiness. The surface is 

 not so smooth ; indeed the individual scales may be distinctly perceived 

 with a lens ; their bases are olive-bronze ; their tips dark brown, with 

 quite a faint bluish tinge, and to the naked eye the surface appears of 

 a unicolorous olive-brown. The fascia does not appear to be quite 

 so posteriorly placed as in N. betulicola, and is vertical ; it is at the 

 same time rather narrow, of uniform width, inclining to yellowish, but 

 perceptibly less glossy. Beyond it the surface is darker, with a very 

 faint violet-blue tint, which also prevails at the base of the cilia, 

 whereas their tips are rather dark gray. The posterior wings and 

 their cilia are gray, slightly inclining to brownish. In the much 

 smaller female which I refer here the antennae are short, the anterior 

 wings a little more bronze-coloured, and the fascia is broader, hence 

 appears to be nearer the base. 



This species is further distinguished from N. glutinosae and N. mi- 

 crotheriella by the ground colour not being so blue, especially at the 

 tip of the wing, and by the paler, more brownish colour of the poste- 

 rior wings and their cilia. From the former it also differs by the 

 broader and more glossy fascia, from the latter by the longer antennae 

 of the male, by the rather duller fascia being throughout of uniform 

 width. N. luteella has the antennae and anterior wings shorter, the 

 tip of the latter of a bright violet-blue ; the fascia is nearer the base, 

 close beyond the middle, more inclining to luteous, and is ill defined, 

 especially towards the costa, and not metallic. N. turicella has the 

 ground colour of the anterior wings more of an olive-gray, with a dull 

 white, distinctly oblique fascia, edged with dark towards the base, and 

 posteriorly rather concave ; it has also paler cilia and shorter whitish 

 antennae. There are specimens of N. malella in which the anterior 

 wings are of the same colour as in N. distinguenda, but that species 

 is readily distinguished by the more brilliant fascia being placed 

 nearer the base, and by the distinct cilial line. 



I once bred both sexes from birch leaves at the same time, before 

 I was acquainted with N. betulicola and N. luteella, and at that time 

 had not examined the larva and mine sufficiently. Last autumn I 

 found a single larva in a birch leaf, which appeared to me distinct 

 from the larvae of the remaining birch Nepticulae, but hitherto [it has 

 not produced an imago. It may belong to N. distinguenda. This 

 larva was wax -yellow, the mine tortuous, quite filled up with dark 

 excrement. 



Brunswick. 



