Diglotta mersa (Haliday) of the Diglottini, a western Palaearctic species, is reported for the first time from the Atlantic coast of North America (Canada, New Brunswick, Dipper Harbour). It was found in fine gravel under small (10-15 cm diameter) rocks in the intertidal zone, approximately 2 m below the mean high tide mark. A description, and images of the external body, median lobe of aedeagus, spermatheca and terminal segments are provided. New distributional and bionomic data for Halobrecta flavipes Thomson, a coastal species of the Athetini Casey, are presented.