The earthworms of England belong entirely to the three genera Lumbricus, Allolobophora and Allurus, which are further subdivided by some systematists; and these genera form the prevalent earthworm fauna of the Palaearctic region and are also very numerous in the Nearctic region.
Linnaeus recognized only one species of earthworm and named it Lumbricus terrestris.
During the winter earwigs lie dormant; but in the early months of the year females with their eggs may be found in the soil, frequently in deserted earthworm burrows.
In Benhamia caecifera and at least one other earthworm there are numerous caeca, one pair to each segment.
The humble earthworm also plays a vital role in Chris ' Chelsea garden.