254 [April, 



(therein di&eriug horn rhynchosporella), hut have a powdery appearance ; a blotch 

 of this character lies on the inner margin near the base, and another on the middle 

 of the inner margin ; above this latter is a short black dash in the fold ; beyond the 

 black dash the powdery scales form an obscure angulated fascia (very different from 

 the more definite mark in rhynchosporella, which may be compared to a prostrate V), 

 beyond this are more powdery scales towards the costa, and others along the hind 

 margin ; cilia pale grey, intersected by a dark grey line, in, or before, which at the 

 apex is a minute black dot (more perceptible than any thing analogous which we 

 find in rhy nchosporella) . 



In rhynchosporella, the costa to beyond the middle is more decidedly and 

 broadly dark than in scirpi ; yet there is no denying the fact, that though the 

 insects look different, it is by no means easy to define them by sharp characters. 



This insect was first sent to me by Mr. Barrett in 1S75, he having 

 met with it in a salt-marsh near Pembroke, where he collected it again 

 more freely in 1876 ; it seemed to frequent there a short species of 

 rush. Mr. W. H. B. Fletcher has now bred it freely from larvae 

 collected in the leaves of Scirpus onaritimus near Worthing, and 

 by the help of his bred specimens, I have been able to sketch out the 

 characters above given, Mr. Fletcher having also kindly given me 

 his ideas as to the points of distinction between the two species. 



Mountsfield, Lewisham, S.E. : 

 March \Uh, 1887. 



On the life-history of JElachisia scirpi. — While staying in the New Forest in 

 June, 1883, the Rev. C. D. Digby told me that in the previous summer he took in 

 the Yarmouth Marshes specimens of an Elachista, which he thought might be of an 

 undescribed species. Accordingly, about the middle of the month, we went together 

 to the Isle of Wight. In the evening we found the insect flying in swarms at 

 intervals between 5.30 and dusk. So abundant was it, that although towards the 

 end of the flight I only boxed good specimens, I set one hundred, all males, the 

 next morning before breakfast. In April, 1884, I searched among the herbage for 

 the larvae. At the south end of the Marsh there was growing on a little mud bank, 

 so that one could place the leaves between one's eyes and the sun, what I then took 

 for a fine-leaved grass, but now believe to have been Jiincus Gerardi. In some of 

 these leaves were small Elachista larvse, from which i-csulted a few E. cygnipennella, 

 and a dwarfed male of E. scirpi. Neither Mr. Digby nor I was able to make much 

 more of this clue until May, 1886, when, while collecting larvae of Bactra in a ditch 

 near Worthing, I found some Elachista larvae in the leaves of Scirpus maritimus, 

 which proved to be those of our old Yarmouth friend. The mines are short and 

 broad, and usually placed in the upper half of the leaves. The larva bores upwards 

 or downwards, depositing its " frass " in long dark masses in the middle of the mine, 

 and at the end of it opposite to that at which it feeds. The empty part of the mine 

 is pale greenish-white, and very conspicuous. 



The following description of the larva was taken on May 25th : — Length, f-in. ; 

 tapering posteriorly ; head pale yellow, dark brown about the mouth ; body pale 



