Geraldine Reid

Fossils and the tropics, the Eunotiaceae (Bacillariophyta) expanded: A new genus for the Upper Eocene fossil diatom Eunotia reedii and the recent tropical marine diatom Amphora reichardtiana

The diatom subclass Eunotiophycidae has recently expanded in composition. While it still includes a single order, the Eunotiales, and two families, the Eunotiaceae and Peroniaceae, the former includes four genera, Eunotia, Actinella, Semiorbis and Desmogonium, while the Peroniaceae includes only one, the genus Peronia. After discovery of the predominantly Southern Hemisphere genus Eunophora, a freshwater taxon superficially resembling species of Amphora, other species of diatoms with similarly confusing morphology have come into sharper focus. The recently described genus Amphorotia, based on Eunotia clevei, may be sister taxon (its most closest relative) to Eunophora. This paper presents evidence for including a Miocene, marine, fossil species, Eunotia reedii, with the more or less tropical species, Amphora reichardtiana, in the same genus. Relationships among the Eunotiaceae are further clarified.

DIATOM BIOGEOGRAPHY AND WATER BABIES: THE SEARCH FOR MEANING AMONG THE PROTISTS

“But there are no such things as water-babies.” “How do you know that? Have you been there to see? And if you had been there to see, and had seen none, that would not prove that there was none. And no one has a right to say no water-babies exist till they have seen no water-babies existing; which is quite a different thing, mind, from not seeing water-babies; and a thing which nobody ever did, or perhaps ever will do, you know that?” (Kingsley, 1863)

Systematics of the Gyrosigma balticum complex (Bacillariophyta), including three new species

Three new species in the genus Gyrosigma Hassall (G. caliG. Reid sp. nov., G. gibbyiG. Reid sp. nov. and G. murphyi G. Reid sp. nov) are described. A cladistic analysis on the basis of 10 morphological characters, was undertaken to investigate the interrelationships of these new species within Gyrosigma. As well as ‘standard’ cladistic analysis, which apportions equal weight to all characters, a posteriori differential weighting was also investigated. Pleurosigma subtilis Brébisson is transferred to Gyrosigma, as G. subtile (Brébisson) G. Reid comb. nov., because it is more closely related to other species of Gyrosigma than to Pleurosigma Smith. G. balticum var. californicum Grunow in Cleve and Möller is elevated to specific status [as G. californicum (Grunow in Cleve and Möller) G. Reid stat. nov.], because it does not form a monophyletic group with G. balticum (Ehrenberg) Rabenhorst.

THE MARINE DIATOM GENUS CLIMACONEIS (BERKELEYACEAE, BACILLARIOPHYTA): TWO NEW SPECIES FROM ABU DHABI, UNITED ARAB EMIRATES

Two new species of the marine biraphid diatom genus Climaconeis collected from several localities in Abu Dhabi, The United Arab Emirates, are described using light and electron microscopy. The new species are compared to other members of the genus and a key is provided.

Origin and Diversity of the Diatom Genus Eunotia in Lake Baikal: Some Preliminary Considerations

The benthic diatom flora of Lake Baikal is poorly known and its origins obscure. In this chapter, we outline the distribution of the diatom genus Eunotia, in particular taxa related to the unusual species E. clevei, and discuss the implications. We believe there are two distinct series of relationships, expressed both geographically and phylogenetically. One, derived from E. clevei sensu stricto, extends through the Boreal (with extinctions in Japan and the USA); the other, related to E. lacusbaikali, is in China, extending north towards Southeast Asia. These two “routes” have implications for the Lake Baikal flora and the diversity of the Eunotia flora in the Far East.

A NEW FOSSIL SPECIES OF TETRACYCLUS (BACILLARIOPHYCEAE) FROM THE MIOCENE DEPOSIT OF TUNKA RIDGE, LAKE BAIKAL, SIBERIA, RUSSIA

Tetracyclus tscheremissinovae sp. nov., a new fossil Miocene diatom from Tunka Ridge, Lake Baikal, Siberia, is described. Comparison is made with similar extinct species and the palaeo-biogeographic implications of their distribution are discussed. A preliminary note on the holdings of the Baikal Museum is included.

Fine structure of Delphineis minutissima and D. surirella (Rhaphoneidaceae)

Delphineis Andrews is a marine araphid pennate diatom genus belonging to the family Rhaphoneidaceae Forti, which has three distinct subgeneric groups around D. lineata Andrews, D. ovata Andrews and D. surirella (Ehrenberg) Andrews, respectively. Living cells and frustules of three taxa in the D. surirella group were studied using light and scanning electron microscopy. Delphineis minutissima (Hustedt) Simonsen is characterized by small, circular to elliptical valves in which the sternum is as narrow as the virgae. The valve outline of D. surirella is broadly elliptical to lanceolate and the straight sternum is laterally expanded at the apices. Delphineis australis comb. nov. has broadly elliptical valves and a sternum that is slightly narrower at the middle of the valve. Delphineis minutissima and D. surirella share the following fine structure features; no granules, plated rota with two spokes, two rimoportulae per valve and two small pores at each apex. The epicingulum of D. minutissima and D. surirella is composed of several open bands; the first and second bands open at opposite ends, the more distal bands are short.

NOTES ON THE GENUS SEMIORBIS PATRICK WITH A DESCRIPTION OF A NEW SPECIES

A review of the genus Semiorbis is given, including its taxonomic history, a discussion of its current taxonomic position and morphological descriptions. One new species is described and one new combination. Comments on the relationships of Semiorbis with the family Eunotiaceae are made. Semiorbis rotundus sp. nov., is known only from North America; Eunotia catillifera is transferred to the genus Semiorbis.

THE DIATOM SLIDE COLLECTION AND BIBLIOGRAPHY OF THE REVEREND RICHARD FRASER BASTOW (C. 1888–1ST OCTOBER 1960)

An inventory of Richard Fraser Bastows diatom type slides is given along with a biographical sketch and full bibliography. Details of the whereabouts of Bastows type slides are included along with geographical details and nomenclatural notes. Light microscope images are provided for all lectotypified taxa. Bastows collections were primarily made in Britain and he was involved in an abortive attempt to write a British diatom flora. Some background to this project is provided.

PLEUROSIGMA OBSCURUM W. SMITH OR GYROSIGMA OBSCURUM (W. SMITH) GRIFFITH ET HENFREY? THE TALE OF TWO GENERA

The generic placement of Gyrosigma obscurum (W. Smith) Griffith & Henfrey has been questioned in recent years, its position moving between Gyrosigma and Pleurosigma. The recent paper of Reid (2002a) caused some concern and Sterrenburg proposed that obscurum should be placed in Pleurosigma. This paper reinvestigates the claims of both Reid and Sterrenburg to conclude that the generic placement of obscurum is clearly more closely related to species of Gyrosigma than to species of Pleurosigma. Reanalyses of Reids data set substituting the character coding advocated by Sterrenburg for striae arrangement and using the concepts of Sterrenburg in the cladistic analysis still shows that obscurum is more closely related to species of Gyrosigma than to species of Pleurosigma.