172 BRITISH ANNELIDS.
peculiarity about this worm which renders it very easy of identifica-
tion. When placed on its back it will be seen that the under surface
of the girdle forms an oval, or tends to a circular shape. Eisen first
observed and figured this very accurately, in his account of the
worms of Scandinavia.
Mr. Allen has sent me specimens from Plaistow, and Mr. Day
from one or two localities around Epping Forest.
3. Allolobophora turgida, Eisen. The Turgid Worm has
been a crux for the student of earthworms, but thanks to the industry
of a few patient workers, who prefer accuracy to fame, we have at
last been able to see it satisfactorily differentiated from all the other
species with which it was formerly confused, and can give it a definite
character. It is larger than the last and of a duller hue, being
usually of a greyish colour behind, with an orange girdle and flesh-
coloured head. The girdle extends over segments 28 to 34, and if
a specimen which is passing into the adult stage is carefully exam-
ined, the puberty pores will be found to occupy two alternate
segments—31, 33. In the Green Worm the same segments are
occupied, but there are three pairs, extending to the 35th, while there
is a marked difference in their shape and appearance. If a perfectly
adult Turgid Worm is examined the pores will be found so swollen
as to appear to cover the intervening segment, when it will be diffi-
cult for anyone but an adept to distinguish it from the next species.
While the dorsal pores of the two foregoing are between segments
4 and 5, and are easily identified, in the Turgid Worm they begin
between 10 and 11, and are found with difficulty. This is one
feature which marks off the members of the group, and it is accom-
panied by another. The Green and Mucous Worms deposit a solid
substance with their mucus; this and the next do not.
I have to record the Turgid Worm for Epping Forest, Purfleet,
Rainham, Plaistow, Barking, Woolwich, and elsewhere; the consign-
ments in each case reaching me through Mr. Allen and Mr. Day.
4. Allolobophora trapezoidea, Duges. Eisen did splendid
service by his careful diagnosis of worms twenty years ago, but it has
been, left for Rosa in Italy, and myself in this country, to complete
the unravelling of the tangled skein into which previous writers had
brought the whole subject of earthworm diagnosis. In former years
several species were lumped together under the title of the Common
Worm (Lumbricus communis, Hoffmeister). Now we have entirely
discarded this vague and misleading epithet, and given to each