The genus Butlerius Goodey, 1929 includes about 10 species and can be found in Europe, North- & South-America and Asia. All species are carnivorous in behaviour and and can be found inhabiting soil, in compost, mosses and decaying plant roots.
They have relatively long labial setae and a large mouth cavity with a large dorsal tooth and two smaller subventral teeth. Females have two ovaries. Both sexes have a long filiform tail. The genus and type species (B. butleri) were named after the English writer Samuel Butler (1835-1902).
More pictures of Butlerius:
(Click on the pictures for an enlargement, ©Wageningen University & Research, Laboratory of Nematology/Pictures: Hanny van Megen)