Species Description: With the generic characteristics of Haslea (see H. amicorum). This species is lanceolate (Fig. 1A, SEM of external surface, modified from Figure 48 in Sterrenburg et al. 2015; Fig. 1B, SEM of external surface, from IRL ) with few, if any, structures such as striae or axial area visible in the light microscope. Thus, electron microscopy is needed for identification. The cells are delicate and fragile. The transverse striae on the basal layer are offset, i.e., the striae on one side of the raphe line up well with the interstriae on the other side (Fig. 2, SEM, detail of Fig. 1; Fig. 3, SEM of internal surface). The external central raphe endings are in small depressions or pits which often fuse in the axial area (Fig. 2, SEM detail of Fig. 1A). Valves are 85-110µm long and about 10-12µm wide, with ~ 23 transverse and ~ 30 longitudinal striae in 10µm. Areolae in the basal layer are square (Fig. 3).
This species occurs occasionally in the IRL system, and otherwise is known only from the type locality, Måsoy, Norway.
Sterrenburg FAS, Tiffany MA, Herwig WE, Hargraves PE. 2015. Seven new species expand the morphological spectrum of Haslea. A comparison with Gyrosigma and Pleurosigma (Bacillariophyta). Phytotaxa 207: 143-162.