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 Pleurosigma diverse-striatum Meister (1935: 102) ( Fig. 62 ) References : Hendey 1970 , p. 152, pl. 6, fig. 62; Al-Handal 2009 , p. 24, fig. 153; Stidolph et al. 2012 , pl. 8, fig. 166. Features : Length 60–90 μm, width 16–20 μm, oblique striae 18–22 in 10 μm, transapical striae 16–18 in 10 μm. Description: Valves sigmoid-lanceolate with acutely rounded apices. Raphe branches sigmoid, central, and eccentric near the apices. Axial area narrow, central nodule small and rounded. Striae appear in oblique and transverse rows. Oblique striae crossed each other at angle of 65 o . Remarks : Under light microscope, this species looks rather similar to Pleurosigma inflatum Shadbolt (1853: 16) but can only be separated by raphe angle which is +8–13 o in P. inflatum and +17–22 o in P. diverse-striatum . Ecology and Distribution: A widely distributed marine species. Previously reported from the Gulf both from muddy and sandy sediment ( Hendey 1970 , Al-Handal 2009 , Al-Yamani & Saburova 2011). Frequent in Basra corals.