SOAR : WATER MITES OF EPPING FOREST. 99
Genus 4—THYAS, KOCH.
T. venusta, Koch.
A red mite, without swimming hairs. Cuckoo-pits, 1898. 
T. thoracata, Pier,
This has a number of chitinous plates distributed over
the dorsal surface. Loughton. 1910.
Sub-Family—DIPLODONTINAE.
Genus 5—DIPLODONTUS, DUGES.
D. despiciens, Mull.
Quite a common red mite, found in all parts of the Forest.
Family 4—HYDRACHNIDAE.
Sub-Family—HYDRARACHNINAE.
Genus 6—HYDRARACHNIA, MULL.
H. globosa, de Geer.
Another red mite; not very common. Snaresbrook
and Wake Ponds, 1897.
H. geographica, Mull.
This is the largest of all the water mites known in the
Britannic area. The gravid female sometimes is as
much as 8 mm. long. It is black and red in colour.
It has been found in the Forest several times. Snares-
brook, 1895.
H. scutata, Pier.
Snaresbrook, 1910.
H. schneideri, Koen.
Snaresbrook, 1896.
Family 5—HYGROBA TIDAE.
Sub-Fam.—HYGROBATINAE.
Genus 7—HYGROBATES, KOCH.
H. longipalpis, Herm.
The type species of this genus. East London Water-
works, 1908.
Sub-Fam.-SPERCHONINAE.
Genus 8.—SPERCHON, KRAM.
S. squamosus, Kram.
Very rare. Oak Hill 1899.
Sub-Fam.—LEBERTIINAE.
Genus 9.—LEBERTIA, NEUM.
L. porosa. Sig, Thar.
East London Waterworks, 1908.