Dimeregramma Ralfs, 1861
Lectotype species: Dimeregramma minus (W.Gregory) Ralfs
Original publication: Pritchard, A. (1861). A history of infusoria, including the Desmidiaceae and Diatomaceae, British and foreign. Fourth edition enlarged and revised by J. T. Arlidge, M.B., B.A. Lond.; W. Archer, Esq.; J. Ralfs, M.R.C.S.L.; W. C. Williamson, Esq., F.R.S., and the author. pp. [1]-xii, [1]-968, 40 pls [I-XV]. London: Whittaker and Co..
Request PDFType designated in: Boyer, C.S. (1927). Synopsis of North American Diatomaceae, Supplement, Part 2. Naviculatae, Surirellatae. Proceedings of the Academy of Natural Sciences of Philadelphia 79: 229-583.
Description: Cells more-or-less rectangular in girdle view, joined to form filaments. Cells touching along the complete valve face or only at centre and apices. Plastids plate-like, probably two lying alongside the girdle. Lives in the marine littoral but details not known; probably associated with sediments or sand grains. Valves linear to elliptical, sometimes subrostrate. Valve face almost completely flat or slightly elevated at centre and apices. Sternum narrow or centrally expanded. Striae uniseriate, slightly radiate, containing round areolae that open externally into grooves sunken between prominent transapical ribs. Areolae with cribra near outer face. Mantles shallow; smooth or finely granular. Bifurcating nodulose spines arise from the transapical ribs near the valve margin, apparently involved in linking the cells into filaments. Small nodules also occur on the ribs. No rimoportulae. Apical pore plates present, in some samples with minute spinules externally. Copulae split, curved at apices, and with single rows of areolae. Valvocopulae much wider than subsequent copulae and narrowed at the abvalvar edge at both poles; second copula with broad 'ligula' to fill the wide gap between split end of the valvocopula. At least four copulae in the complete cingulum.
The most recent alteration to this page was made on 2017-08-16 by M.D. Guiry.Taxonomic status: This name is of an entity that is currently accepted taxonomically.
Gender: This genus name is currently treated as neuter.
Most recent taxonomic treatment adopted: Li, C.L., Ashworth, M.P., Witkowski, A., Dabek, P., Medlin, L.K., Kooistra, W.H.C.F., Sato, S., Zglobicka, I., Kurzydlowski, J., Theriot, E.C., Sabit, J.S.M., Khiyami, M.A., Mutwakil, M.H.Z, Sabit, M.J., Alharbi, N.S., Hajarah, N.H., Qing, S. & Jansen, R.K. (2015). New insights into Plagiogrammaceae (Bacillariophyta) based on multigene phylogenies and morphological characteristics with the description of a new benus and three new species. PLoS ONE 10(10): 1-26.
Comments: A common genus, having affinities with Plagiogramma (excl. Plagiogrammopsis) and Glyphodesmis. These genera form a distinctive group from the view both of structure and ecology and we place them in a family (Plagiogrammaceae).
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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=44390
Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 16 August 2017. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 22 November 2024
