NATURAL HISTORY OF BRITISH FRESH-WATER LEECHES. 79
" B. Body brown, the brown pigment being disposed in the
form of minute longitudinal and transverse striae ; the six dorsal
rows of dots more or less dispersed into irregular blotches.
" C. Body olive brown or brown, the pigment not striated,
the longitudinal dark brown lines less distinct ; without spots in
regular rows ; the anterior pair of eyes sometimes absent."
Habits.—This species is very sluggish and rolls itself up like
a wood louse when touched. It is of common occurrence in
ponds and streams on water plants and under stones and twigs.
It is parasitic upon water snails—Limncsa, and Planorbis. Hard-
ing says that it also attacks larvae of Chironomus ("Bloodworms").
The eggs are laid during April and May, about 50 being produced.
The eggs are carried by the parent on the under side of the
body, and are hatched in about 10 days. The young attach
themselves to the body of the mother, but frequently leave
her to make little excursions on their own account.
Distribution. — Britain:—Common everywhere. R. Stort ;
Walthamstow Reservoirs ; nr. Clacton (per Mr. Picton); Higham's
Park ; ponds, Epping Forest; R. Roding, near Abridge (speci-
mens from this locality are nearly all var. B.) ; New Barnet;
R. Chess; Totteridge; Bletchingley, Surrey; Staines (R.
Colne, var. B.) ; Seven Arches, Leeds (H. W.) ; Carlisle (Friend,
17) ; R. Porter, Yorks (Evans, 15); near Norwich (Brightwell,
9) ; R. Whiteadder, Berwicks (Johnston, 32) ; Scilly Isles (W.
Blair).
Ireland :—Dingle and Ventry, Co. Kerry; Tempo, Co. Fer-
managh ; Clonbrock, Co. Galway; Cashel, Co. Tipperary ;
Lough Neagh and Coleraine; Holywood and Belfast, Down-
patrick (Scharff, 39).
Foreign :—Germany (Johannson, 30) ; S. Norway (Jensen,
29) ; Italy, Spain, Hungary, France, Sweden, Denmark, Saxony,
Bohemia, Russia, Siberia, America (Blanchard, 5).
Helobdella stagnalis L. (=Clepsine bioculata). Plate
VI., Fig. 6.
Description.—Body flat, lanceolate, nearly transparent and of
a greyish or greenish colour, with fine black spots. Length from 8-12 mm.
long and 2-4 mm. across. One pair of eyes. A characteristic feature
is a brown, chitinous plate situated in the middle line on the dorsal surface
between rings 12 and. 13. This plate often has a colony of Epistylis
upon it, and is the remains of a byssus-gland which serves to attach
the young to the body of the parent before the suckers are developed.
Habits.—This species is very active and is common in ponds.