Size: 4.3-4.8mm
Basic colour: Dark brown, elytra almost black, irredescent. Segment 2-4 of antennae slightly darkened.
Pronotoum: Dark reddish brown. with sides strongly rounded, with sharp, slightly protruding tooth and hind angles; hind margin straight.
Leg colour: Light brown.
Confusion species: Trechus obtusus
, Confusion species: Trechus quadristriatus

Size: 5.3-6.5mm
Basic colour: Dark reddish brown, elytra each with a pale apical spot, and sometimes also a paler area near shoulder.
Pronotoum: Rounded laterally with hind angles marked by a small tooth.
Leg colour: Appendages pale brown.
Confusion species: Trechus obtusus

Known from Yorkshire, Devon and near Dublin.