Demonax cambrensis sp. nov. resembles the east Pacific Demonax medius (Bush), but is thinner though just as long and has less than 15 axial cells in a radiole cross section. Demonax torulis sp. nov. resembles Demonax japonicus (Moore) in having thoracic tori so small that they do not indent the ventral shields, but differs in having broad-hooded inferior thoracic setae. Both benefit by enrichment of the sediment with sewage sludge.