(Morrow) Reid and Williams 2010 Category: Eunotioid
BASIONYM: Eunotia catillifera Morrow 1981
Valves are weakly arcuate. The dorsal margin is more strongly curved than the ventral margin. In larger specimens, a weakly gibbous shoulder can be observed on the dorsal margins near the apices. Apices are subcapitate, slightly recurved dorsally and narrow (2.0-2.5 µm) . Striae are nearly parallel and are interrupted by a hyaline line near the ventral margin. The striae are separated by externally thickened, transapical costae. The costae terminate on the dorsal margin as prominent, planar wing- or spine-like projections. A reduced raphe is present on the ventral face-mantle junction at the apices, but it can be difficult to discern in LM. Areolae are not resolvable in LM. Rimoportulae are absent.
Basionym: Eunotia catillifera
Author: Morrow 1981
Length Range: 10-42 µm
Width Range: 2.8-6.1 µm
Striae in 10 µm: 11-14
Frustule in ventral girdle view rectangular, in dorsal view sometimes broader in middle than on ends. Dorsal valve margin strongly convex, ventral margin slightly concave. Ends of valve rostrate-capitate. Terminal nodules above ventral margin near valve apices. Striae parallel, alternating with plates which obscure them. Plates fin-like, diminishing in size toward valve ends. Raphe partly on ventral valve mantle and partly on valve face. Striae 11-14 in 10 µm. Length 10-42 µm. Breadth 2.8-6.1 µm.
Cite This Page:
Burge, D., and Edlund, M. (2016). Semiorbis catillifera. In Diatoms of the United States. Retrieved October 22, 2016, from http://westerndiatoms.colorado.edu/taxa/species/semiorbis_catillifera
Species: Semiorbis catillifera
Reviewer: Jen Beals
Morrow, A.C., Deason, T.R. and Clayton, D. (1981). A new species of the diatom genus Eunotia. Journal of Phycology 17: 265-270.
Reid, G. and Williams, D.M. (2010). Notes on the genus Semiorbis Patrick with a description of a new species. Diatom Research 25: 355-365.
Semiorbis catillifera was described from epiphytic and epipsammic habitats in a shallow, slightly acidic stream in western Florida (Morrow et al. 1981). The images shown here are of the holotype slide.