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surface strongly reticulated, especially on thorax resem- 
bling scales. 
Anterior wings very long and narrow, provided with 
very strong fringe, which at longest is longer than wing 
at broadest. Subcosta short, almost half as long as mar- 
ginal vein, which is hardly one third of the wing-length. 
Radius short, stigma insignificant. Surface of wing pro- 
vided with short hairs, which have a tendency to regu- 
larity, 3 or 4 regular rows are seen. Basal portion of 
wing to stigma smoky, as well as along costal margin; 
the wings being as a whole somewhat opaque. Posterior 
wings lineshaped without hairs on surface. Fringe at 
posterior margin long, at anterior margin short. Both 
pair of wings with reticulated surface. Legs similar to 
Brachista thickly furnished with long strong hairs and also 
similar to Brachista provided with very large claws. 
Wingless and subapterous female as a whole darker, 
almost black on the dark parts. Sense-organs on antenne 
more strongly developed. 
Male apterous: much lighter than females. Antenne 
appear to be much more strongly provided with sense- 
organs than in the winged females. Penis short, light at 
apex. Entire surface being strongly reticulated as in the 
females. 
Each segment of abdomen of all forms as well as 
ovipositor provided with scanty but strong hairs. 
Doubt has been expressed by several authors as to 
how far the winged females are able to fly. The only 
occasion on which I have found Prestwichia aquatica 
was 27/, 1905 at Donse. I swept the specimen from an 
Umbelliferous plant that grew on the banks of Donse 
Dam. The locality was such that the specimen must ab- 
solutely have flown to have reached this plant which 
stood away from the water. 
This species, which lives in water, in which it swims 
by help of its legs has been found and bred often in 
