1. Lothar Geitler

   • Die Herausgeber

   Announcement 20 December 2005 Pages: 1 - 1

2. Lothar Geitler on the occasion of his 90^th birthday on May 18^th 1989

   • The Editors

   Announcement 20 December 2005 Pages: 2 - 2

3. List of publications of Lothar Geitler (since 1979)

   OriginalPaper 20 December 2005 Pages: 3 - 3

4. Subjects and taxa treated in the scientific work of Lothar Geitler

   OriginalPaper 20 December 2005 Pages: 5 - 15

5. Heteropolarity in unicellular cyanobacteria: structure and development ofCyanocystis violacea

   • MaoSen Hua
   • E. Imre Friedmann
   • Susan B. Campbell

   OriginalPaper 20 December 2005 Pages: 17 - 26

6. Alternative models for the development of the pattern of spaced heterocysts inAnabaena (Cyanophyta)

   • C. P. Wolk

   OriginalPaper 20 December 2005 Pages: 27 - 31

7. Geitlerinema, a new genus of oscillatorialean cyanophytes

   • Konstantinos Anagnostidis

   OriginalPaper 20 December 2005 Pages: 33 - 46

8. Trichome structure of fourAphanizomenon taxa (Cyanophyceae) from Czechoslovakia, with notes on the taxonomy and delimitation of the genus

   • Jiří Komárek
   • L'ubomír Kováčik

   OriginalPaper 20 December 2005 Pages: 47 - 64

9. Ultrastructure ofCyanoptyche gloeocystis f.dispersa (Glaucocystophyceae)

   • Ludwig Kies

   OriginalPaper 20 December 2005 Pages: 65 - 73

10. Gymnodinium aeruginosum (Dinophyta): A blue-green dinoflagellate with a vestigial, anucleate, cryptophycean endosymbiont

    • E. Schnepf
    • S. Winter
    • D. Mollenhauer

    OriginalPaper 20 December 2005 Pages: 75 - 91

11. Flagellar apparatus ultrastructure inMesostigma viride (Prasinophyceae)

    • Michael Melkonian

    OriginalPaper 20 December 2005 Pages: 93 - 122

12. Three new green coccoid zoospore-producing algae from the Great Smoky Mountains National Park, Tennessee, U.S.A.

    • T. R. Deason
    • W. R. Herndon

    OriginalPaper 20 December 2005 Pages: 123 - 132

13. Ein Beitrag zur Kenntnis vonApatococcus lobatus (Chlorophyta, Chaetophorales, Leptosiroideae)

    • Georg Gärtner
    • Elisabeth Ingolić

    OriginalPaper 20 December 2005 Pages: 133 - 143

14. Comparative ultrastructure of pyrenoids inTrebouxia (Microthamniales, Chlorophyta)

    • Thomas Friedl

    OriginalPaper 20 December 2005 Pages: 145 - 159

15. Developmental studies in trebouxioid algae and taxonomical consequences

    • Elisabeth Tschermak-Woess

    OriginalPaper 20 December 2005 Pages: 161 - 195

16. Cell multiplication and ultrastructure ofMicrasterias denticulata (Desmidiaceae) grown under salt stress

    • Ursula Meindl
    • Doris Wittmann-Pinegger
    • Oswald Kiermayer

    OriginalPaper 20 December 2005 Pages: 197 - 208

17. Mallomonas alphaphora (Chrysophyceae), a new species from Western Australia

    • Hans R. Preisig

    OriginalPaper 20 December 2005 Pages: 209 - 214

18. The species concept in diatoms: Evidence for morphologically distinct, sympatric gamodemes in four epipelic species

    • David G. Mann

    OriginalPaper 20 December 2005 Pages: 215 - 237

19. Geitler's “Plattenband” in the diatomSynedra cf.ulna in the light of TEM investigations

    • Anna-Maria M. Schmid

    OriginalPaper 20 December 2005 Pages: 239 - 252

20. New observations onPorphyridium griseum Geitler =Rhodella grisea (Geitler) comb. nova (Porphyridiales, Rhodophyceae)

    • J. Fresnel
    • C. Billard
    • B. Pekárková

    OriginalPaper 20 December 2005 Pages: 253 - 262

21. Cell morphology and growth characteristics ofPorphyridium aerugineum (Rhodophyta)

    • Blažena Pekárková
    • Jan Šmarda
    • František Hindák

    OriginalPaper 20 December 2005 Pages: 263 - 272

22. Desmarestia antarctica (Desmarestiales, Phaeophyceae), a new ligulate Antarctic species with an endophytic gametophyte

    • Richard L. Moe
    • Paul C. Silva

    OriginalPaper 20 December 2005 Pages: 273 - 283

23. Lateral hydrodynamic effects of rotating filaments

    • Robert Jarosch

    OriginalPaper 20 December 2005 Pages: 285 - 322