COMMUNICATIONS 
TO THE 
MONTHLY MEETING 
OF THE 
YORKSHIRE PHILOSOPHICAL SOCIETY, 
1886 . 
NOTES ON THE HYDRABEPHAGA FOUND 
NEAR YORK. 
The neighbourhood of York is singularly rich in Hydra- 
dephaga. Even yet it abounds in suitable localities, such as 
bogs, ponds, undrained commons, and sluggish streams. 
Every year, however, these places diminish in number and 
extent. It is therefore very desirable that this Society should 
possess a record of the most remarkable species, with a few 
notes upon their habitats, their time of appearance, and their 
comparative rarity. 
Hydroporits Scalesiamis Steph. is confined in England (so far 
as present knowledge goes) to a single moss-grown pond in 
Askham Bog, where it may be taken in moderate abundance 
in April. A pair of this insect was taken in Norfolk somewhere 
about 1825, but it was never heard of again in England till 
rediscovered at Askham Bog by Archdeacon Hey some 
forty years ago. This is one of many signs of affinity between 
Askham Bog and the Fen country. This species has a wide 
foreign distribution, occurring in Northern France, Germany, 
and Sweden. 
Hydroporus oblongus, Steph. occurs in company Avith H. 
Scalesiamis, and only in that pond, so far as my experience 
goes. It appears as early as the middle of March, but is 
always scarce, and does not appear, I believe, after May. 
