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 sublaevigata Álvarez-Blanco and S. Blanco ( Figs 20–26 ) Material studied: —Wild material ( ECT 4119) from subtidal sediments and benthic scrapings collected near the Caribe Hilton at Condado Lagoon, San Juan , Puerto Rico ( 18° 27.6’ N , 66 °5.1’ W ). Description: —Valves were 28.6–92.1 μm long and 2.5–5.3 μm wide ( Figs 20–22, 25 ). Outlines were lanceolate: convex in the middle and either linear to weakly convex in the flanks narrowing towards the apices. The ends either continued to converge, or exhibited a weak concave reflex. Each sternum was lanceolate (thicker in the middle than at the apices of the valve: Figs 20, 21, 23, 24 ). Striae were biseriate. Virgae were densely packed ( 50–54 in 10 μm). An asymmetric rimoportula occurred at each pole ( Figs 23, 24, 26 ). Girdle bands were dissociated from one another and the valves in the cleaned cultured material, but all girdle bands found in the cultured material were without pores and all were open (not illustrated). Remarks: —Our Puerto Rican specimens overlapped in measurements reported for Mediterranean Sea type material (26.5–34.1 μm long, 2.3–3.0 μm wide, Álvarez-Blanco & Blanco 2014 ), and had the same valve outline and lanceolate sternum. Both had asymmetric rimoportulae, and ocellulimbi were of the same dimensions (6–8 pores wide by three high). Girdle band morphology was not reported for the type , so no comparison between our material and the type material is possible.