. Bulletin of the British Museum (Natural History), Geology. BRYOZOANS FROM UPPER CRETACEOUS OF ALBERTA, CANADA 21 quately resolved using an optical microscope and full descrip- tion demands the use of scanning electron microscopy. Only one other formally described cheilostome species is known to occur in the uppermost Cretaceous of the Western Interior province. This is Villicharixa lintonensis (Cuffey, Feldmann & Pohlable, 1981), distinguished from E. bicysto- sum by the presence of a gymnocystal tubercle on the proximal edge of the opesia, multiple small spine bases encircling the opesi
. Bulletin of the British Museum (Natural History), Geology. BRYOZOANS FROM UPPER CRETACEOUS OF ALBERTA, CANADA 21 quately resolved using an optical microscope and full descrip- tion demands the use of scanning electron microscopy. Only one other formally described cheilostome species is known to occur in the uppermost Cretaceous of the Western Interior province. This is Villicharixa lintonensis (Cuffey, Feldmann & Pohlable, 1981), distinguished from E. bicysto- sum by the presence of a gymnocystal tubercle on the proximal edge of the opesia, multiple small spine bases encircling the opesia, a negligible cryptocyst, and a different early budding pattern (see p. 22). Elsewhere, Upper Creta- ceous membraniporimorph bryozoans have been described from the Ripley Formation of Tennessee (Canu & Bassler, 1926), and from many localities in Europe (, see Voigt, 1979, 1981, 1983). Few of these species possess distolateral spine bases of the type characterizing E. bicystosum. Mem- branipora gegania Brydone, from the lower Maastrichtian of Norfolk, England, does have a distolateral pair of spine bases, but study of the holotype (SMC B36555) has revealed several differences from E. bicystosum: the autozooids in M. gegania are larger and broader, small ovicells are present, and large pore chambers occur. Membranipora frontalis Levinsen, described from the lower Maastrichtian of Den- mark, seems also to have broader autozooids than E. bicysto- sum and apparently possesses pore chambers; it may be a senior synonym of M. Distribution. Drumheller marine tongue, Horseshoe Can- yon Formation, Edmonton Group (lower Maastrichtian); localities HS, HT and DR, near Drumheller, Alberta, Can- ada. Also recorded by Sanderson (1931: 1254) and Allan & Sanderson (1945: 79) from the Fox Hills Sandstone (lower to middle Maastrichtian) of southern Alberta; however, this record requires confirmation as the specimens have not been figured and may alternatively be Villicharixa
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