FIGURES 31–37 in Taxonomy of three new Rhoicosphenia (Bacillariophyta) species from California, USA

FIGURES 31–37. Type material of Rhoicosphenia stoermeri from Bear Creek, Los Angeles County, California, USA. SEM. 31, 33, 34. External views of the D-valve show the shortened raphe branches and lineolate areolae (31, 33). Distal raphe end on D-valve terminates on valve face at head pole (33) and continues onto mantle at foot pole (34). Proximal raphe ends on D-valve (31, 33, 34) are dilated and drop-shaped. 32, 35, 36. Internal D-valve with troughs between the virgae as well as lineolate internal openings to the external areolae (32, 35). Pseudosepta are present at each pole and raphe branches extend beyond the pseudosepta at each pole (32). Valvocopula modified to cover pseudosepta on valve interior (35, 36). Interior views of head and foot pole with crook-shaped internal proximal raphe ends (35, 36). 37. In girdle view, valve flexure is illustrated and girdle elements are each ornamented with one row of simple poroids Scale bars are 10 μm (32, 37), 5 μm (31), and 1 μm (33–36).