270 [October, 



1879-80, p. 131; P. parvulus, id., Ent. Nachr., viii, p. 211 ; id., in 

 Eostock's Netzfliigler Deutscblands, Anhang, p. 188. 



Allied to P. phceopterus, Steph., but about one-fourth smaller, and the wings 

 much paler. The entire body is dark brown, with black ejes and ocelli. Wings 

 pale hyaline-grey, with darker neuration. 



Forma microptera, $ . With rudimentary wings, scarcely one-half the length 

 of the abdomen in the living insect, and with abbreviated reticulation. 



About two dozen examples were taken on the outskirts o£ Lynd- 

 hurst, New Porest (August 31st and September 1st, 1890), on a paling. 

 All stages were abundant on the green "mould" which covered the 

 sides of the split branches of which the paling was composed. Over- 

 hanging this paling was a growth of mixed shrubs, and above the 

 spot (a few feet only) where the insects occurred was a yew {Taxus), 

 but I did not succeed in obtaining any of them from it, and I have 

 no doubt they fed on the "mould."* 



Kolbe knew of only a single specimen from Westphalia, and at 

 first placed it as a variety of his alhoguttatus {nee Dalm. ; = suhpupil- 

 Zai^«s, McLach.), afterwards, in Ent. Nachr., he considered it a distinct 

 species, and in his appendix to Rostock's work it is made to follow 

 plicBopterus, and end the genus. 



That my insect is specificially different from p)^<^op)terus there can 

 be no doubt, according to its small size and very pale smoky-grey 

 wings, which are much paler (and the insect much smaller) than the 

 occasional pale forms of the (^ of plicEopterus. 



Naturally, it is slightly risky to identify a species with one 

 described from a single specimen only in so obscure a group, but my 

 insect quite accords with Kolbe's description, and I have a long series 

 which certainly maintain its distinction from phceopterus, to which it 

 is no doubt allied, rather than to suhpupillatus. 



I think I have both sexes of the fully-winged form ; that with 

 aborted wings is certainly ? . 



In Ent. Nachr. (/. c), and in Rostock's Netzfliigler (J. c), Kolbe 

 calls attention to a microscopic difference in what he terms the " cell 

 formation " of the membrane of the wings, which is more open in 

 parvulus than in the allied species. I have placed the wings under a 

 1-inch objective, with A-eyepiece. Under this comparatively low 

 power, I find the membrane in plicsopterus and subpupillatus very 

 densely studded with what appear as minute dark points ; in the 

 insect I consider as parvulus, these dark points are much less dense ; 

 the so-called "points " I take to be the "cells " as defined by Kolbe. 



Lewisham, London : 



September Sth, 1890. 



* This so-called " mould " is in reality a microscopic Alga. 



