98 SOAR : WATER MITES OF EPPING FOREST.
for members of any other. They are found in fresh water only;
for, although there are some marine mites which superficially
appear to be closely related to this group, they are quite distinct
and are known under the family name of Halicaridae.
The water-mites are easily divided into groups. Some
have the eyes close together: others have the eyes wide apart.
Some are simply crawlers: others are powerful swimmers.
Then there are hard skins and soft skins. It is easy, therefore,
to split these little creatures into genera, with such marked
characters in their external structure.
Altogether, we have represented in the Forest twenty
genera, including 52 species—about one-fifth of the whole
recorded for the Britannic area.
SUB-ORDER—HYDRACARINA.
Family 1—LIMNOCHARIDAE.
Genus 1—LIMNOCHARES, LATR.
L. aquatica, Latr.
A bright scarlet crawling mite, with eyes on a small
chitinous plate on the median line of the dorsal surface.
Not common in the Forest. Snaresbrook, 1899.
Family 2—EYLAIDAE.
Genus 2—EYLAIS, LATR.
E. georgei, Soar.
A bright red mite, soft skinned. Eyes close together
on a small chitinous plate. A strong powerful swimmer,
but without swimming hairs on the fourth pair of legs.
Wake Ponds, 1899.
E. rimosa, Pier.
Much like E. georgei. except in the eye plate. Wake
Ponds, 1902.
Family 3—HYDRYPHANTIDAE.
Sub-Fam.—HYDRYPHANTINAE.
Genus 3:—HYDRYPHANTES, KOCH.
H. ruber, de Geer.
Common; found in several places in the Forest.
H. dispar, Schaub.
Not so common as ruber. It was found at Loughton and
Chingford, 1900-06.