﻿Like Velia and Gerris, it is at present impossible to determine 

 whether the apterous specimens constitute a distinct species: 

 that they are not pupas I am convinced, because I have found 

 them in that state when they are smaller with rudimentary 

 elytra; and as I now possess males and females of both, it is 

 evident that the winj^s do not indicate a sexual distinction. 

 These insects must therefore either be distinct species, or else 

 they sometimes have and sometimes have not wings : this may 

 well be a very difficult question, for if we were to find a well- 

 known species of bird in its adult state at times with and at 

 others without winsfs, no doubt it would very much embarrass 

 the ornitholoifist. Entomology, however, presents so many 

 anomaiies, that it will not be judicious to consider such as a 

 parallel case. I confess that 1 am inclined to believe the Hy- 

 drometrae are two distinct species ; at the same time I freely 

 admit that there are so many instances of Hemipterous in- 

 sects being found somelinics winged and at others apterous 

 or semiapterous in their perfect state, that such variations may 

 only arise from temjierature or casualties wilii which we are 

 unaccjuainted, unless indeed it be a pseudimago state, as I have 

 already promulgated at folio 681. 



1. stagnorum I Ann. — Curt. B. E. apterous figure (5". 

 Velvety brownish-black : elytra narrow and shorter than 



the thorax, sometimes with a longitudinal testaceous line at 

 the base of the head and a double one on the thorax ; mar- 

 gins sometimes ochreous : base of first two joints of antenna? 

 and legs, excepting the extremities of the joints, ochreous. 



2. alatus Curt. Brit. Ent. winged specimen ?. 



Velvety brownish-black : elytra ample, brown, variegated 

 with ochre; wings semitransparent brown, nervures dark: 

 hinder portion of thorax and abdomen often testaceous, centre 

 of the latter shining : antennae and legs ochreous and fuscous 

 as in H. stagnorum. 



For a fine winged pair I am indebted to the Hon. C. A. 

 Harris, who took 4 males and females the middle of August, 

 with an abundance of apterous specimens and several pupa3 

 on a branch of the Stour, which runs through the grounds of 

 the Earl of INIalmesbury at Heron Court. Mr. Dale has 

 taken them at Rydal water, Cumberland, the end of August, 

 and Mr. Marshall at Hornsey. Mr. W. Clifton found both 

 winged antl apterous specimens on pulling up grass in the 

 middle of a swainjiy field in June, on Barnes Conunon, in great 

 abundance; also at Wandsworth, at the roots of trees on re- 

 moving the grass; and I may add that I have taken them 

 winged in June in the New Forest, but I have generally ob- 

 served H. stagnorum on the sides of rivers and rutming 

 brooks in April and May, but I found the larvit and imago 

 untler stones on the shores of Loch Fad in August. 



The jiiant is Scrophularia aqunlico, W'atei" l'"igwt)rt. 



