( l-^'^ ) 
VI. On the Hydroptilida^, a Family of the Ti-iclioptera. 
By the Rev. A. E. Eaton, M.A. 
[Read 3rd February, 1873.] 
Trichoptera in general, but more es}3ecially tlie Hydropti- 
lid(E, are an annoyance to the Lepidopterist. If he Kves 
near a river they are a constant source of disappointment to 
him Avhenever, on a summer evening, he inspects the ento- 
mological miscellany Avhich accumulates upon his table- 
cloth beneath the gaslight. Down falls a scorched and 
crippled " Micro — " ; he has the trouble of looking at it ; 
but his first glance detects the scabrous clothing of the 
anterior wings of a Micro-Trichopteron, whose hair looks 
as if it had been brushed the wrong way, in lieu of the 
scales of a Micro-Le]Hdopteron ; and his only consolation 
is that he may leave the pinning of that kind of things to 
the Trichopterists. 
A great similarity of ornamentation prevails amongst 
congeneric species of the HydroptilidcB ; and the density 
of their hair prevents structures of dried specimens from 
being made out with certainty, besides concealing the 
neuration of the wings completely. Consequently most 
entomologists have been deterred from the study of this 
family of insects, and little is known about them. Up to 
the present time only two genera have been defined, and 
fourteen or fifteen species. Of these one species is fossil, 
seven or eight are European, and the rest are from Ma- 
deira, North America, Ceylon and New Zealand. In 
addition to these I have been able to determine four 
genera and six species, of which species five are British. 
Mr. M'Lachlan most kindly sent all of his specimens 
o^ HydroptilidcB to me, Avith ]5ermission to subject them 
to most ruthless treatment. This has enabled me to effect 
some reductions in synonymy, and to verify some points 
in their geographical distribution. I have also examined 
Stephens' and Wollaston's collections in the British 
Museum. 
TRANS. EXT. SOC. 1873. — PAET II. (mAY.) 
