Metzeltin, Lange-Bertalot and García-Rodríguez 2005 Category: Symmetrical biraphid
Contributor: Marina Potapova - April 2011
Length Range: 16-22 µm
Width Range: 4.5-5.4 µm
Striae in 10 µm: 10-11
Valves are rhombic-lanceolate with sightly drawn-out apices. The axial area is narrow and linear. The central area is small, round or transversely elliptical. The raphe is straight, filiform, with slightly expanded external proximal ends. The distal raphe ends are deflected to the secondary valve side. The striae are mostly biseriate, radiate in the valve center and convergent at the apices. The areolae are elongated, mostly oriented along the apical axis. Internally the striae open into shallow alveoli. A hyaline area and one apical row of areolae are present at each end of the valve.
Author: Metzeltin, Lange-Bertalot and García-Rodríguez 2005
Length Range: 18-25 µm
Width Range: 4-6 µm
Striae in 10 µm:
Differential diagnosis compared to Hippodonta capitata ssp. capitata. Valves all more or less rhombic-lanceolate to lanceolate, tapeing gradually to the ends that are at most very gently protracted and broadly rounded (not distinctly set off capitate or rostrate-subcapitate). Length 18-25 μm, breadth 4-6 μm (not 6-7 and eventually up to 10 μm as reported in Patrcick & Reimer 1966). Raphe, areae, striae not significantly different. Hence the valve putlines combined with lower breadth are the only differential characters.
Metzeltin, D., Lange-Bertalot, H. and García-Rodríguez, F. (2005). Diatoms of Uruguay. Compared with other taxa from South America and elsewhere. In: H. Lange-Bertalot (ed.), Iconographia Diatomologica. Annotated Diatom Micrographs. Vol. 15. Taxonomy-Biogeography-Diversity. A.R.G. Gantner Verlag K.G. 15:736 pp.
NADED ID: 213010