Systematics of araphid diatoms with asymmetric rimoportulae or densely packed virgae, with particular attention to Hyalosynedra (Ulnariaceae, Bacillariophyta) Author Sabir, J. S. M. Genomic and Biotechnology Research Group, Department of Biological Sciences, Faculty of Science, King Abdulaziz University (KAU), Jeddah 21589, Saudi Arabia Author Theriot, E. C. Department of Integrative Biology, University of Texas at Austin, Austin, Texas, USA Author Lobban, C. S. Division of Natural Sciences, University of Guam, Mangilao, Guam 96923, USA Author Alhebshi, A. M. Genomic and Biotechnology Research Group, Department of Biological Sciences, Faculty of Science, King Abdulaziz University (KAU), Jeddah 21589, Saudi Arabia Author Al-Malki, A. L. Department of Biochemistry, Faculty of Science, KAU, Jeddah 21589, Saudi Arabia. Author Hajrah, N. H. Genomic and Biotechnology Research Group, Department of Biological Sciences, Faculty of Science, King Abdulaziz University (KAU), Jeddah 21589, Saudi Arabia Author Khiyami, M. A. King Abdulaziz City for Science and Technology, Riyadh 11442, Saudi Arabia. Author Obaid, A. Y. Department of Chemistry, Faculty of Science, KAU, Jeddah 21589, Saudi Arabia. Author Jansen, R. K. Genomic and Biotechnology Research Group, Department of Biological Sciences, Faculty of Science, King Abdulaziz University (KAU), Jeddah 21589, Saudi Arabia & Department of Integrative Biology, University of Texas at Austin, Austin, Texas, USA Author Ashworth, M. A. Department of Integrative Biology, University of Texas at Austin, Austin, Texas, USA text Phytotaxa 2018 2018-04-10 347 1 1 49 http://dx.doi.org/10.11646/phytotaxa.347.1.1 journal article 10.11646/phytotaxa.347.1.1 1179-3163 13707999 Hyalosynedra hyalina (Grunow) Álvarez-Blanco and S. Blanco ( Figs 17–19 ) Basionym: — Synedra laevigata var. hyalina Grunow (1877 , 166) Material studied: —Wild ( KSA 2015-14) and cultured ( UTKSA 0189) material from algal turfs collected at 1 m depth near the Bhadur Resort, Jeddah, Kingdom of Saudi Arabia . FIGURES 17–19. Hyalosynedra hyalina from culture UTKSA0189. 17. SEM. Left specimen, interior whole valve. Right specimen, exterior whole valve. 18. SEM. Left specimen, interior of valve apex. Right specimen, exterior of valve apex. 19. LM of whole valve. Description: —Valves were 25.9–90.3 μm in length, and 3.3–6.2 μm in width ( Fig 17, 19 ). Each sternum was evenly thin along the entire valve ( Figs 18, 19 ). Apices were protruded and capitate. Valves had finely packed virgae ( 56– 60 in 10 μm) separated by biseriate striae. The weakly sunken ocellulimbi were 3 rows of pores tall externally, at least 4 rows tall internally ( Fig. 18 ), and about 14 pores wide. Usually 2 spines were over each ocellulimbus. There was an asymmetric rimoportula at each apex occurring at the junction of the terminal depression. Girdle bands were dissociated from one another and the valves in the cleaned cultured material, but all girdle bands found were without pores and all were open (not illustrated). Remarks: —Although the largest specimens were slightly larger than those previously reported ( Álvarez-Blanco & Blanco 2014 ), they were alike in other respects with illustrated specimens of S. laevigata var. hyalina ( Grunow 1877 ) and of H. hyalina ( Álvarez-Blanco & Blanco 2014 ) . Unlike the apices of H. laevigata , those of H. hyalina were strongly protruded and capitate.