Taxonomic revision and morphological cladistics analysis of the diatom genus Anorthoneis (Cocconeidaceae), with description of Anorthoneis arthus-bertrandii sp. nov. Author Pennesi, Chiara Dipartimento di Scienze della Vita e dell’Ambiente, Università Politecnica delle Marche, via Brecce Bianche, 60131 Ancona, Italy Author Majewska, Roksana Unit for Environmental Sciences and Management, North-West University, Potchefstroom 2520, South Africa & Dipartimento di Scienze e Tecnologie Ambientali Biologiche e Farmaceutiche, Seconda Università di Napoli, 81100 Caserta, Italy Author Sterrenburg, Frithjof A. S. National Natural History Museum “ Naturalis ”, Leiden, Stationsweg 1581852 LN Heiloo, The Netherlands Author Totti, Cecilia Dipartimento di Scienze della Vita e dell’Ambiente, Università Politecnica delle Marche, via Brecce Bianche, 60131 Ancona, Italy Author Stefano, Mario De Dipartimento di Scienze e Tecnologie Ambientali Biologiche e Farmaceutiche, Seconda Università di Napoli, 81100 Caserta, Italy text Phytotaxa 2018 2018-02-02 336 3 201 238 http://dx.doi.org/10.11646/phytotaxa.336.3.1 journal article 10.11646/phytotaxa.336.3.1 1179-3163 13720104 Anorthoneis arthus-bertrandii De Stefano & Pennesi , sp. nov. ( Figs 130–143 ) Diagnosis:— valvae late ellipticae, 16–22 μm longae, 13–18 μm latae. Areovalva concava in area axiali et leviter convexa in area marginali. Sternum excentrico, lineare cum nodulo centrali conspicuo et eccentrico. Areovalva habet in valvae lato structuram striis cum monoseriatis ( 14–18 in 10 μm) quae constant ex areolis oblongis ( 10–14 in 10 μm). Implicatae rotae partes exteriores areolarum occludunt. Areovalva habet in limbo structuram striis biseriatis quae constant ex poroidis qui occlusi sunt hymenibus rimis cum inaequalibus. Raphovalva habet raphem rectam cum nodulo centrali et nodulis terminalibus oblongis. Striae monoseriatae ( 18–20 in 10 μm) quae constant ex poroidis qui occlusi sunt hymenibus rimis cum inaequalibus. Utraque valvocopula secta et caret fimbriis. Holotype :— slide MDS 9 deposited at the Herbarium of the Stazione Zoologica “Anton Dohrn” of Naples, Italy . Figures 142 , 143 illustrates the holotype specimens. Type locality:— INDONESIA . Epiphytic on seagrasses leaves collected in October 2005 along the coasts of Siladen Island, Sulawesi , Indonesia, ( 1° 38′ 25.23″ N , 124° 48′ 06.61″ E ). Collected by Dr. Francesca Azzini, October 2005 . Etymology:— the specific epithet refers to Yann Arthus-Bertrand in recognition of his outstanding service in the promotion of scientific knowledge and its dissemination. Description:— Valves broadly elliptical to ovoid in outline ( Figs 130, 133 , 136, 139, 142 and 143 ). Apical axis: 16–22 μm, transapical axis: 13–18 μm. SV :— Externally, valve face slightly concave with a convex mantle, ending in a small marginal area covered by a row of very small pores ( Fig. 130 ). The eccentric sternum narrow, linear, developed entirely within the valve face, terminating close to the valve face-mantle junction ( Fig. 130 ). Central area small, circular, with very small, irregular, imperforated pores ( Figs 130, 131 ). Transapical striae strongly radiate, 14–18 in 10 μm, uniseriate, becoming biseriate in the last row of the mantle striae ( Fig. 132 ). Areolae circular to squared, 10–14 in 10 μm, internally occluded by rota-like vela ( Figs 131–135 ). Internally, the valve surface structures appear similar to the external ones, except for the larger central area ( Fig. 133 ). RSV :— Externally, valve concave to convex close to the margin. The margin is covered by two irregular rows of very small pores ( Fig. 136 ). Raphe-sternum asymmetric, narrow and linear developed entirely within the valve face ( Fig. 136 ). Proximal raphe endings slightly expanded, coaxial, converging within a small, roundish and clearly asymmetrical central area ( Figs 136, 137 ). Distal raphe endings similar in shape, terminate in roundish submarginal areas ( Figs 136, 138 ). Transapical striae strongly radiate, 18–20 in 10 μm, uniseriate in the valve face becoming biseriate in the mantle ( Fig. 136 ). Areolae small, rounded, 22–24 in 10 μm, internally occluded by perforated vela ( Figs 139, 140, 141 ). On the mantle margin, at the end of each biseriate striae, one smaller areola is present ( Figs 136, 138 ). Internally, both the raphe-sternum and the small central nodule only slightly thickened ( Figs 139, 140 ). Proximal raphe endings simple, deflected in opposite directions ( Figs 139, 140 ); distal ones terminate in vestigial helictoglossae ( Figs 139, 141 ). Valvocopula open, with a smooth inner margin.