Frankophila biggsii Lowe, Morales & Kilroy
CHR 574150, New Zealand, Punakaiki, wet rock bluff by Fox River; Rex L. Lowe, 3 March 2005.
Isotypes: CAS 221088 (Diatom Herbarium, California Academy of Sciences); GC 120001 (Diatom Herbarium, Academy of Natural Sciences of Philadelphia); GC 876 (NIWA Herbarium, National Institute of Water & Atmospheric Research, Riccarton, New Zealand).
Institution holding the type material
Westland: Fox River, Punakaiki. Known from two wet, vertical, limestone walls.
EtymologyAfter Dr Barry Biggs, New Zealand National Institute of Water and Atmospheric Research, a pioneer in freshwater algal ecology in New Zealand.
Frustules rectangular in girdle view forming filaments of up to 30 cells held together by interlocking spines. Valves elliptic with rounded apices in valve view. Length 8-15 µm, width 4.5-5 µm, depth of frustule 4.5-6.5 µm, striae density 11-12 in 10 µm. Striae short, restricted to the valve-face margins leaving a broad axial area. Striae composed of 2 rows of loculate areolae, extending onto the valve mantle. Spines solid, dichotomously branched, located on the costae.
Raphe slits <1 µm long, confined to the valve apices. Helictoglossae very small, raised just above the valve's interior surface. Abvalvar margin of mantle curved, broader at the centre than at the ends. Cingulum closed. Valvocopula broader than the rest of the girdle elements, often bearing rough siliceous elongated deposits not common in fragilarioid diatoms.