E. A. Harper Gray 321 
Subsequent enquiries showed that since 1914 at least twenty loads of 
night-soil had been brought to an allotment within twenty yards of the one 
where the leech was found. This appears to have some significance as to its 
occurrence, when one considers Harding’s reference to examples being found 
in sewage channels near Manchester, though one would have expected to 
find Trocheta subviridis in the allotment treated with night-soil, rather than 
in one situated about twenty yards away. Harding, however, describes the 
species as amphibious, “frequently leaving the water in order to pursue its 
prey in moist situations upon land,” so that, owing to the waterlogged condi¬ 
tion of the allotments during winter, there would be an opportunity of moving 
from the well sunk in the clay, or from water in the allotment containing the 
night-soil. 
It may be that the species is not so rare as the few records of its occurrence 
would lead one to suppose, for, as Harding points out, its superficial resem¬ 
blance to an earthworm might lead to its being overlooked, and it is well to 
add a record of its occurrence so far north in England. 
Trocheta subviridis is interesting economically in being carnivorous, its 
food consisting of earthworms, and it is credited with eating insect larvae 1 . 
1 Loc. cit. Harding, p. 186. 
