Previously only two bryozoan species, Berenicea maloniana and Heteropora tipperi, have been documented in the Jurassic rocks of North America; Jurassic bryozoans were known primarily from British, French, and German species. Five additional species, three of them new, are described herein from the Mid-Jurassic Twin Creek Limestone in western Wyoming. Most common is an erect delicate branching cyclostome, Entalophora stokesi n. sp., which occurs in oolites near Kemmerer, accompanied by rare encrusting sheetlike cyclostomes, Berenicea duofluvina n. sp., another delicate branching form (Entalophora? sp. indet.), and threadlike boring ctenostomes, Ropalonaria arachne (Fischer, 1866), previously known only in Europe. Erect sheet-or cuplike cyclostomes, Diastopora cutleri n. sp., are found in micrite near Jackson. Equivalent-age calcarenites (Carmel Formation) at Buckhorn Draw in south-central Utah yielded a few additional specimens of Entalophora stokesi n. sp.--Modified journal abstract.