252 BRITISH LEPIDOPTERA. 



medium nitida alba ; capillis fuscis. Exp. al. 2 lin. Head fuscous. 

 Antennae fuscous, basal joint whitish. Anterior Avings shining 

 fuscous, with a faint violet tinge beyond the middle ; beyond 

 the middle is a nearly straight, shining whitish fascia ; cilia fuscous. 

 Posterior wings pale grey, with pale grey cilia. Appears in May and 

 August. The larva mines the leaves of the sorrel in autumn, and in 

 July ; the mine is very peculiar ; it makes a series of concentric circles 

 till, as though the centrifugal force at length became too great, it flies 

 off at a tangent into an irregular tortuous gallery. It has only 

 hitherto been met with by Mr. Shield, near Dublin, in some sorrel 

 plants growing among furze bushes, consequently in sheltered 

 situations. Mr. Shield has only succeeded in rearing a single specimen, 

 which .... he has placed in my collection. As it is extremely 

 hazardous to describe Nepticulae from single specimens, the above 

 description of the perfect insect must be looked upon as an approxi- 

 mation only ; from the habit of the larva, no doubt can attach to its 

 being a distinct species (Insecta Britannica, p. 303). In 1855, Stainton 

 writes : " Being better acquainted with the species, I give an improved 

 description." This reads as follows : " Head fuscous, sometimes with 

 a few ochreous hairs. Antennas dark fuscous, basal joint whitish. 

 Anterior wings rather dull bronzy-fuscous bsyond the middle, with a 

 dull violet fascia, followed by a rather curved silvery-white fascia, 

 which is slightly concave towards the base ; the apex of the wing and 

 cilia are dull violet-fuscous. Posterior wings pale grey, with pale grey 

 cilia " (Ent. Ann., 1855, 1st Ed., p. 55). 



Imago. — Head fuscous. Anterior wings 3-4 mm. (the smallest 

 British moth) ; dull bronzy-fuscous, with a dull violet fascia beyond the 

 middle, followed by a nearly straight silvery-white fascia, cilia fuscous. 

 Posterior wings and cilia pale grey. 



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

 acetosella. 



Mink. — The larva, as soon as it hatches, passes from the under to 

 the upper side of the leaf, on which the egg was laid, mining a minute 

 ring around the point of entrance. It then makes a gallery, consist- 

 ing of a series of circles, each successive one being made larger. The 

 three inner circles become bright red in colour, and in this part of the 

 mine it is difficult to trace the thread of excrement. The outer rings 

 (usually three or four) are whitish, and in these a central line of black 

 excrement is clearly discernible. The larva then changes the circular 

 plan of the gallery, mining irregularly about the leaf, which it finally 

 quits for pupation. Sang says that the mines are difficult to find, 

 and (especially when small) very difficult to distinguish from the 

 ordinary spots and discolorations, always present on the leaves. 



Larva. — The full-fed larva is 2 lines in length ; pale amber-yellow 

 in colour, shining and transparent ; the dorsal vessel greenish ; the 

 head pale amber, faintly tinged with brown, and with two darker 

 lines receding from the mouth ; anal segment pale greenish (Stainton). 



Cocoon. — The cocoons examined (a dozen or more) measure from 

 about 1-25 to 1-75 mm. in length, and -6 to -75 mm. in width. Each is a 

 rough oval in outline, rather wider at one end than at its nadir. There is 

 an ill-developed ring surrounding the cocoon medially, but nowhere 

 developing into a marked flange. It is very thin, and collapses 

 readily, composed of white silk, that turns yellowish with age. The 



