A new boring ctenostome bryozoan without calcareous skeleton, Orbignyopora opulenta sp. nov. (Vesiculariida, Eurystomata), is described from deposits of the Middle Callovian of the Moscow Region. A pioneering microct examination of a colony of this species reveals its diagnostic features hidden in the shell substratum: shape, size, and distinctive features in the budding of zooids and stolons, and also tubular pro cesses (tubulets) developed on the frontal surface of autozooids. The diagnosis of the genus Orbignyopora is added by dimorphism of autozooids (Azooids and Bzooids) and spindly kenozooids.