Masoncus

Masoncus is a genus of North American dwarf spiders that was first described by Ralph Vary Chamberlin in 1949.

Species
it contains four species, found in Canada and the United States:
 * Masoncus arienus Chamberlin, 1949 (type) – USA,
 * Masoncus conspectus (Gertsch & Davis, 1936) – USA
 * Masoncus dux Chamberlin, 1949 – Canada
 * Masoncus pogonophilus Cushing, 1995 – USA. Known myrmecophilic association with Pogonomyrmex badius, this spider lives in the nest and feeds on springtails.