Pseudo-eunotia Grunow, 1881
Lectotype species: Pseudo-eunotia doliolus (Wallich) Grunow
Currently accepted name for the type species: Fragilariopsis doliolus (Wallich) Medlin & P.A.Sims
Original publication: Van Heurck, H. (1881). Synopsis des Diatomées de Belgique Atlas. pp. pls XXXI-LXXVII [31-77]. Anvers: Ducaju et Cie.
Type designated in: Hustedt, F. (1927). Die Kieselalgen Deutschlands, Österreichs und der Schweiz unter Berücksichtigung der übrigen Länder Europas sowie der angrenzenden Meeresgebiete. Bd. VII: Teil 1: Liefrung 1. In: Rabenhorst's Kryptogamen Flora von Deutschland, Österreich und der Schweiz. (Anon. Eds), pp. -272. Leipzig: Akademische Verlagsgesellschaft m.b.h..
Description: Frustules linear in girdle view, slightly wedge-shaped, joined by neighboring valve surfaces to form barrel-shaped colonies. Plastids not described. Valves linear, subarcuate, one amrgin being almost straight and the other convex with slightly capitate apices. Striae biseriate (10-12 in 10_m), consisting of fine transapical areolae in quincunx arrangement, areolae with internal cribra. Between each pair of striae a transapical costa, raised on valve surface and also extending into valve interior as a pseudoseptum. About halfway between each apex and center of the valve one costa is curved towards its neighbor, and the stria between them consists on only one row of puncta. Costae and striae continue on mantle without interruption on rapheless margin; on raphe-bearing margin costae end in blunt projections above the raphe, with alternating costae and striae reestablished below on the mantle. Raphe marginal, lying at the boundary of the valve face and mantle on the convex side of the valve. Raphe a continuous slit, curving slightly downward onto the mantle at each apex. Internal raphe system fibulate, fibulae corresponding to costae, which sometimes branch. A longitudinal costa joins the fibulae, with portulae formed between them; this costa interrupted at middle of raphe system. Copulae smooth, of constant width on straight side of valve and gradually widening toward center on convex side, thus creating wedge shape of frustule. Nature of pleurae, if any, unknown. A marine planktonic taxon collected in tropical to subtropical seas. Most similar to some species of Nitzschia, from which it differs by its asymmetry with respect to the apical axis, and the wedge-shaped frustule. Medlin and Sims (1993) have proposed that P. doliolus be transferred to Fragilariopsis Hustedt (1913), a "larger and better known genus".
Information kindly contributed by C. Sancetta but may now be outdated.
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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=43715
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 18 February 2016. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 01 October 2023