A review of the genus Brachysira in Ireland with the description of Brachysira praegeri and Brachysira conamarae, new raphid diatoms (Bacillariophyceae) from high status waterbodies Author Kennedy, Bryan Author Allott, Norman text Phytotaxa 2017 2017-10-20 326 1 1 27 http://dx.doi.org/10.11646/phytotaxa.326.1.1 journal article 10.11646/phytotaxa.326.1.1 1179-3163 13699655 Brachysira vitrea (Grunow) Ross in Hartley ( Figs 52–60 ) Morphologically the outline is typically broadly elliptic-lanceolate with distinctly capitate poles.Valves with subcapitate ends ( Figs 52 & 59 ) were occasionally encountered. Valve dimensions (n=29): length 19.5–32 μm, width 5.5–7.5 μm and striae density 32–36 in 10 μm. B. vitrea was found predominately in lakes. Although encountered across a broad alkalinity gradient, it occurred only at low densities (<0.7%) in near neutral lakes (pH=6.8) of low alkalinity (4.0 mg/l CaCO 3 ) and reached maximum abundance (1.4%) in higher alkaline calcareous lakes which were often marl precipitating ( 68–155 mg /l CaCO 3 ; pH: 8.0–8.1). Morphology and ecology conforms well to that outlined by Lange-Bertalot & Moser (1994) and Hoffmann et al. (2013).