Contributions towards an understanding of the Atomariinae (Coleoptera, Cryptophagidae) of Atlantic Canada

The Atomariinae (Coleoptera: Cryptophagidae) fauna of Atlantic Canada are surveyed. Ten species in the genus Atomaria are reported in the region, six of which, including Atomaria distincta Casey, Atomaria fuscata Schonherr, Atomaria lederi Johnson, Atomaria lewisi Reitter, Atomaria testacea Stephens, and Atomaria nigrirostris Stephens, are newly recorded in Canada. Atomaria lederi and A. lewisi are newly recorded in North America. Twenty-three new provincial records are reported. Atomaria curtula Casey, 1900  (syn. n.) is designated as a synonym of Atomaria lewisi Reitter; Atomaria ovalis Casey, 1900 (syn. n.) is designated as a synonym of Atomaria apicalis Erichson, 1846; and Atomaria saginata Casey, 1900 (syn. n.) is designated as a synonym of Atomaria fuscata Schonherr. A key to species is provided, as are species descriptions. Records of all species are given and their distribution in the region is plotted. The global distribution of all Holarctic and adventive species is briefly summarized, and the jurisdictions in North America where they have been reported are compiled. Habitat and bionomic information is also provided for all species, both from within the region, and from observations in European studies. The fauna is briefly discussed from a zoogeographic perspective; two species are Nearctic in origin, five may be Holarctic in distribution, and three others may be adventive Palaearctic species, although further evidence is required to confirm such preliminary assessments. Similarly, because of the paucity of information on this genus, further fieldwork is required to fully discern the distribution of these spe- cies in Atlantic Canada. Three are apparently saproxylic species characteristic of forested habitats; three are primarily grassland species; and the remaining four are eurytopic species found in a wide variety of forested and open habitats.