Marine benthic diatoms in the newly discovered coral reefs, off Basra coast, Southern Iraq Author Al-Handal, Adil Y. Department of Biological and Environmental Sciences, University of Gothenburg, Sweden Author Thomas, Evan W. Biology Department, Waubonsee Community College, Sugar Grove, Illinois, USA Author Pennesi, Chiara Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona, Italia text Phytotaxa 2018 2018-10-12 372 2 111 152 http://dx.doi.org/10.11646/phytotaxa.372.2.1 journal article 10.11646/phytotaxa.372.2.1 1179-3163 13728822 Coscinodiscus marginatus Ehrenberg (1843: 412) ( Fig. 9 ) References : Hendey 1964 , p. 78, pl. 22, fig.2; Desikachary 1988 , pl. 537, figs 1–4, pl. 538, figs 1–6. Features : Diameter 41–70 μm. Description : Valves circular, convex with large hexagonal areolae arranged in quincunx structure. Marginal areolae smaller in size, central area absent. Valve margin broad. Remarks : Deposited from the plankton. Ecology and Distribution : A widely distributed pelagic species. Previously reported from the Gulf ( Al-Kandari et al. 2009 ). Frequent in Basra corals.