Palpi simple; femur, patella, and tibia without any process and without projecting angles; maxillary lobe provided at the base with two strong, conical teeth.

Maxillary lobe of the second pair of feet very long, nearly straight from the base, not attenuated, directed mesad nearly horizontally, and united on the ventro-meson to the lobe from the opposite side without forming a sensible angle; the two together lightly arched on the cephalic border, and forming an even curve.

Sternal piece large, slightly contracted between the fourth pair of coxae, gradually enlarging and obtusely truncate cephalad.

An as yet undescribed species of Leiobunum was first found in the Netherlands in October 2004, although reports date back to at least 2002.

This species has a strong tendency to group together, most of the time protected from wind and direct sunlight, and stay in one place for weeks.