New nassellarian radiolarians are described from the Insular and Intermontane belts of the Canadian Cordillera in British Columbia. Two new genera (Atalanta n.gen. and Nitrader n.gen.) and three new species (Atalanta emmela n.gen., n.sp., Atalanta epaphrodita n.gen., n.sp., and Nitrader montegufonensis n.gen., n.sp.) were found in Lower Jurassic carbonate concretions of the Sandilands Formation of the Queen Charlotte Islands and in a chert pebble extracted from a Cretaceous conglomerate of the Intermontane Belt possibly correlative with the Spences Bridge Group. The discovery of new taxa within two distinct belts of the Canadian Cordillera stresses their biostratigraphic significance.