Lithobius tenebrosus Meinert, 1872

Lithobius is a difficult genus and at least 17 species are known from Britain and Ireland.

Lithobius tenebrosus is one of five 'smaller species' with 2 + 2 forcipular teeth that have backward projections on tergites 9, 11 and 13 that can be confused with the common L. melanops. It differs (among other subtle characters) in having a a single claw on the last leg (L. melanops has an ‘accessory claw’).

More information to allow accurate identification is given in the published identification keys by Tony Barber (2008 & 2009).