nt 
* 
deans ined cae 
Mr. F. W. Edwards on British Iimnobiidae. 227 
(fig. 24) showing several small differences, particularly in the form 
of the ninth tergite and the basal lobes of the side pieces. The 
hypopygium of 7’. claripennis is shown for comparison in Pl. Il. 
fig. 23. 
A single male in the British Museum from Grantown, 
Elgin, 17 viii. 1911 (Lt.-Col. Yerbury). 
T. schummeli sp. n. This is the form which Verrall 
recorded as Z'. unicolor, but Schummel had two species 
under this name which he distinguished by the difference 
in venation. I propose the above name for Schummel’s 
unicolor var. b, the hypopygium of which is shown in 
Pl. II. fig. 21. The type is a male from Brodick, Arran; 
other specimens in the British Museum are from Sussex, 
Bucks, Carnarvon and Sutherland. 
T. unicolor Schum. ‘This species, as now restricted, 
seems to be rarer in Britain than 7’. schummeli ; I have seen 
only three specimens, all taken by Mr. C. A. Cheetham in 
Yorkshire. One of these is remarkable in having a cross- 
vein in the lower basal cell, as in the Scandinavian 7. 
variinervis Zett. Hypopygium, PI. II. fig. 22. 
TRICHOCERA. 
~The work of Keilin and de Meijere on the early stages has 
shown that this genus has no relation with the Limnobidae, 
but is, on the other hand, fairly closely related to Anisopus 
(Rhyphus) and it is now included in the Anisopodidae 
(Rhyphidae) as a separate sub-family. The adults differ 
from the Limnobiidae in the possession of ocelli; the shape 
of the scutum, which does not show the two rounded por- 
tions; the position of Cu,a, always close to the outer 
margin of the discal cell; and also—perhaps a more impor- 
tant point than appears at first sight—in the fact that the 
legs do not at all readily break off. No doubt when the 
comparative morphology of the head and hypopygium has 
been studied in greater detail, important distinctions will 
be found in these organs. While accepting the position 
now assigned to Trichocera by Alexander, it will be con- 
venient to deal with it in this paper. The British species 
at present known can be distinguished as follows :— 
1. Wing-veins conspicuously hairy; Ax ending a little beyond the 
anal angle of the wing; eyes bare; last joint of palpi very 
long, whiplike; ovipositor very short and fleshy 
Diazosma hirtipenne Siebke. 
