BRITISH ANNELIDS.
111
I am making notes on these variations as opportunity permits,
because of their important bearing on many points of interest in this
connection. The body is cylindrical, tapering in front, and
flattened behind. No one seems ever to have called attention to
this fact in its relation to those worms which dwell in the soil but
come forth to feed. The flattened tail is peculiar to these species,
and is of immense importance as a means of securing attachment
to the burrow, and resisting the efforts of enemies to drag the
creature from its hole. An expert will be able almost instantly to
tell the habits of any given specimen submitted to him simply by
the shape of the tail. The disposition of the setae is another
matter with a similar bearing.
The colour of the Long Worm is somewhat similar to that of the
earthworm when found in gardens or rich soil; but I have found it
in some places almost white (var. lactea), while in pastures it is a
dark sienna brown, almost amounting to black on the anterior
portion. The segments number 150 to 200 in a full grown speci-
men. The setae are disposed, as in Lumbricus, in four pairs, the
individuals of which are nearly close together. The under side of
segments 9, 10, 11, where the principal organs are situated, is tumid
and pale, while on the 15th segment the male pore is easily seen
situated on pale papillae. The prostomium cuts the first ring only
partially, but the grooves are very characteristic, as they closely
resemble two arrow heads >< placed opposite each other. The first
dorsal pore is found between segments 12 and 13. Ude was one of
the first to draw attention to this point, and it will be seen by our
diagnosis of the groups that there is almost always a direct relation-
ship between the various members of each group in this respect.
The girdle of the Long Worm usually extends from the 28th to
the 35th segment, three of which (32, 33, 34) bear the tubercula
pubertatis. I have met with some puzzling exceptions, which may
eventually be made the basis of a new system of classification, but
at present they must be kept out of sight.
(To be continued.)