Abstract
Agabus audeni Wallis, known only by the type from south-central British Columbia, is recorded from the eastern foothills of the Rocky Mountains just west of Calgary in southern Alberta. There are notes on its ecology and on its separation from other species, with a key to A. audeni and A. browni Leech. The Holarctic A. coxalis Sharp is discussed, and the Nearctic form referred for the first time to the subspecies ermaki (Zaitzev). Specific characters are illustrated.