238
BRITISH ANNELIDS.
both the foregoing species have their male pore on segment fifteen,
it is found on the thirteenth in Allurus, and thus they may be readily
distinguished. A brief tabular arrangement may present the matter
in clearer light, and help to pave the way for a rather more detailed
account of the different genera :—
Tabular View of British Lumbrici.
Let us imagine the naturalist going out with a collecting tin
lightly filled with damp moss, and securing a dozen specimens of
worms from different localities. He wants to know first of all what
genera he has procured, and takes them out one by one for examina-
tion. With his pocket lens he first examines the head and finds the
first ring cut right through by the lip. This points to Lumbricus.
He next counts the segments from the head to the girdle, and finds
upwards of twenty-two. It cannot, therefore, be Allurus. It is a
dark red or ruddy brown colour, and will therefore not be Allolobo-
phora, unless it is an exception, and then the shape of the mortise
and tenon is decisive.
Putting this aside as a species of Lumbricus, he takes up another.
It is a small worm but mature, or possessed of a girdle, and has a
happy method of progressing tail foremost ; while the tail, instead of
being flat round or oval, is sharp-angled, or square. The mortise
and tenon is imperfect, so it may be either Allurus or Allolobophora
but the male pore is on the thirteenth and the girdle on the twenty-
second segment, so it must be Allurus. Now since we have at pre-