Holotype species: Endictya oceanica Ehrenberg
Original publication and holotype designation: Ehrenberg, C.G. (1844). Mittheilung über 2 neue Lager von Gebirgsmassen aus Infusorien als Meeres-Absatz in Nord-Amerika und eine Vergleichung derselben mit den organischen Kreide-Gebilden in Europa und Afrik. Bericht über die zur Bekanntmachung Geeigneten Verhandlungen der Königl. Preuss. Akademie Der Wissenschaften zu Berlin 1844: 57-97.
Taxonomic status: currently recognized as a distinct genus.
Description: Cells barrel-shaped, joined into short chains. Plastids not investigated. A modern and fossil genus so far only observed by us as separate valves. Reported as a benthic marine genus. Valves broadly cylindrical with sharply defined mantle and valve face. In well-preserved specimens there is a narrow flange at the valve rim in which there is a line of pores. Towards the centre of the valve face are a number of projections. Mantle width one-third to one-half as deep as the valve face. The areolae are variable in size and lie in a heavily silicified framework. They are loculate, with a foramen on the outside and fine pores on the inside. These pores are arranged in rows radiating from the valve centre, being independent of the pattern of the foramina on the outside; in this Endictyua resembles Melosira and Stephanopyxis. Consequently they may be expected to be poroids with rotae in the living cell. Between mantle and valve face on the inner surface are the internal apertures of rimoportulae. These correspond in position to the pores in the flange on the outer surface and run between areolae in fractured specimens. Copulae have not been observed here, but Hustedt (1930) recorded many 'rings' forming the cingulum.The most recent alteration to this page was made on 19 Oct 2011 by M.D. Guiry.
Comments: This is a small genus with only 10 species recognised by VanLandingham (1969). Hustedt (1927-66) reports colony formation in modern material but there do not appear to be true spines and the absence of any other linking mechanism on the valve margin suggests that these cells are solitary. As Hustedt commented, there is considerable confusion in the literature and the taxon has been variously placed in Orthosira, Melosira, Dictyopxis, Coscinodiscus, Stephanopyxis and Craspedodiscus! The genus is clearly in need of re-assessment.
Numbers of names and species: There are 11 species names in the database at present, as well as 1 infraspecific names. Of the species names, 5 have been flagged as accepted taxonomically on the basis of the listed literature under the species name. In some instances, opinions on taxonomic validity differ from author to author and users are encouraged to form their own opinion. AlgaeBase is a work in progress and should not be regarded as a definitive source only as a guide to the literature..
Names: ('C' indicates a name that is accepted taxonomically; 'S' a homotypic or heterotypic synonym; 'U' indicates a name of uncertain taxonomic status, but which has been subjected to some verification nomenclaturally; 'P' indicates a preliminary AlgaeBase entry that has not been subjected to any kind of verification. For more information on a species click on it to activate a link to the Species database):
Click here to also show infraspecific names in the list below.
Verification of data
Users are responsible for verifying the accuracy of information before use, as noted on the website Content page.
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.
Created: 23 April 2002 by M.D. Guiry
Verified by: 19 October 2011 by M.D. Guiry
Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=44395
Please cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2019. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 16 July 2019.