Publications by David Mann:
back upPhD Dissertation, University of Bristol
Nitzschia sect. Lanceolatae
This research was almost contemporary with the first work on Nitzschia sect. Lanceolatae work by Prof. H. Lange-Bertalot and my dissertation refers only to the first major paper by Lange-Bertalot [1977: Eine Revision zur Taxonomie der Nitzschiae Lanceolatae Grunow. Die 'klassischen' bis 1930 beschriebenen Süsswasserarten Europas. Nova Hedwigia 28: 253-307.] I subsequently abandoned work on Nitzschia because of commitment to the generic survey published as Round, F.E., Crawford, R.M. & Mann, D.G. (1990). The Diatoms: Biology and Morphology of the Genera. Cambridge University Press, Cambridge, and because the surveys of Nitzschia by Lange-Bertalot, R. Simonsen and colleagues were already well under way.
In the dissertation, because of the size of the sect. Lanceolatae (which encompasses many hundreds of described species and varieties), I dealt with principles only, using examples familiar to me: I sought to discuss how one might go about establishing a sound species-level classification from morphological data. I believe that, since 1978, the species-level classification of the sect. Lanceolatae has become more confused in most cases, rather than less, although the widespread use of photographs to illustrate valves has improved communication greatly and at least provides a basis for informed discussion.
Chapter 4.6.6.14 (pdfs)
- Text
- Line drawings
- TEM photos
- SEM photos