A new sac-shaped hexactinellid collected from western Canada bearing long lateral prostal spicules was first thought to be a typical Rossellinae. Subsequent examination of its spiculation proved it to have distinctive strobiloplumicomes, typical of the subfamily Lanuginellinae. Other spicules showed it to be a member of the monospecific genus Doconesthes, known previously only from the North Atlantic Ocean. The new species described here as Doconesthes dustinchiversi is only the second known species of the genus and the first to be found in the Pacific Ocean.