Length 7 to 9 mm. There are 15 British species of Agonum, mainly associated with damp habitats and all with rounded pronotum hind angles. Agonum emarginatum is all black, with just its tibiae and tarsi sometimes dark brown.

• toothed mentum (plate on the underside of head before the mouth appendages) = Agonum genus
• 7.5-9mm
• all black (non-metallic)
• very rounded pronotum
• 3rd antennal segment not pubescent, all segments black
• pronotal foveae smooth (depressions at the base of the pronotum)

It is found in damp habitats, usually in marshes or near freshwater.

Mainly spring and summer.

Widespread and abundant in Britain.

Common in Leicestershire and Rutland. There were a total of 65 VC55 records for this species up to March 2015.