Williams and Downie, 1966c
From dinoflaj3
Williams, G.L. and Downie, C., 1966c: Further dinoflagellate cysts from the London Clay. In: Davey, R.J., Downie, C., Sarjeant, W.A.S. and Williams, G.L., Studies on Mesozoic and Cainozoic dinoflagellate cysts; British Museum (Natural History) Geology, Bulletin, Supplement 3, p.215-236.