Valve linear with rostrate to subcapitate apices. Axial area distinct, widening toward teh central area which is a transverse fascia. Striae radiate a the center of the valve, convergent toward the apices. This form is distinguished from the nominate variety by its smaller size and its larger central area in proportion to the length of the valve
(Patrick and Reimer 1966).
Type Locality
Near hot spring, Iceland on ground in front of house (Hlad) Modrn vellir (Kjos) 6/8(Patrick and Reimer 1966).
Synonyms
Pinnularia interrupta f. minor Peters. in Bot. Iceland, vol. 2, pt. 2, p. 405, fig. 25. 1928(Patrick and Reimer 1966).