||Observations on North American Populations of 'Stephanodiscus' (Bacillariophyceae) Species Attributed to Friedrich Hustedt.
Theriot, E. ;
Stoermer, E. F. ;
||Michigan Univ., Ann Arbor. Great Lakes Research Div.;Environmental Research Lab.-Duluth, MN.
North America ;
Great Lakes ;
||Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy.
Stephanodiscus alpinus is moderate in diameter, concentrically undulate and heavily silicified. Spine placement on valves from North American populations is variable and may differ from European material. North American specimens also tend to be more coarsely fasciculate. Stephanodiscus tenuis is distinguished by a rosette of areolae in the valve center. Stephanodiscus dubius is heavily silicified and concentrically undulate. The presence of alveoli near the margin of S. dubius distinguishes it from other Stephanodiscus species. (Copyright (c) 1982, by the American Microscopical Society, Inc.)