Dimeregrammopsis M.Ricard, 1987, nom. inval.

Holotype species: Dimeregrammopsis furcigera (Grunow) M.Ricard

Currently accepted name for the type species: Talaroneis furcigera (Grunow) Sterrenburg

Original publication and holotype designation: Sournia, A. (1987). Atlas du phytoplancton marin. Volume II. Diatomophycées. Vol. 2 pp. 1-215. Paris: Éditions du Centre National de la Recherche Scientifique 15, quai Anatole France - 75700 Paris.

Description: Cells lanceolate, apices attenuate. Oblong in girdle view. A marine genus recorded first from the Balearics but present in material from Barbados kindly supplied by George Andrews. The only taxon we could connect with our material is Dimeregramma furcigerum, which during the final stages of preparation of our book has been made into a new genus Dimeregrammopsis. Valves lanceolate, rounded in transpical section, without a conspicuous valve mantle. Areolar rows transverse with no trace of a sternum, though one is illustrated in Peragallo & Peragallo (1897-1908), Hustedt (1927-66) and in Ricard (1987). A row of simple spines occurs along either edge of the valve. An apical pore field is present at either end and an elongate furrow lies along the apical axis at each end of the valve. Internally the valve is costate with no central break in the transverse costae. Beneath the external apical furrow there is a slightly raised area in which two rows of pores occur. Girdle bands appear plain except for an advalvar row of areolae.

The most recent alteration to this page was made on 2011-10-17 by M.D. Guiry.

Taxonomic status: This name is currently regarded as a synonym of Talaroneis.

Most recent taxonomic treatment adopted: Round, F.E., Crawford, R.M. & Mann, D.G. (1990). The diatoms biology and morphology of the genera. pp. [i-ix], 1-747. Cambridge: Cambridge University Press.

Comments: Although placed in Dimeregramma by early workers it has none of the major characteristics of that genus. The distinctive apices without rimoportulae preclude a position in other araphid genera. Plagiogramma (P. interruptum) also has an apical structure which in the light microscope looks similar but Plagiogramma has distinct pseudosepta and this new genus does not. The girdle view drawn in Hustedt (1927-66) shows a discrete thickening of the cell at the apices corresponding to the apical structure. LM specimens on BM slide 31004 from Pensacola, Montgomery & Miller (1978) figure the same taxon (as Dimeregramma) and show the external apical furrow very distinctly.

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Contributors
Some of the descriptions included in AlgaeBase were originally from the unpublished Encyclopedia of Algal Genera, organised in the 1990s by Dr Bruce Parker on behalf of the Phycological Society of America (PSA) and intended to be published in CD format. These AlgaeBase descriptions are now being continually updated, and each current contributor is identified above. The PSA and AlgaeBase warmly acknowledge the generosity of all past and present contributors and particularly the work of Dr Parker.

Descriptions of chrysophyte genera were subsequently published in J. Kristiansen & H.R. Preisig (eds.). 2001. Encyclopedia of Chrysophyte Genera. Bibliotheca Phycologica 110: 1-260.

Linking to this page: https://www.algaebase.org/search/genus/detail/?genus_id=46624

Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 17 October 2011. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 27 April 2024