portrait

Description:

Originally described by Schewiakoff under the name Nassula elegans.  Although the species Nassula elegans Ehrenberg has been transferred to the genus Nassulopsis Faure-Fremiet, 1959 (Foissner, 1994), the organism described and illustrated by Schewiakoff under the original name does not meet all the morphological criteria for the new taxonomic placement (multiple contractile vacuoles, hypostomial frange that spans the ventral face). Schewiakoff is very firm on the presence of only one contractile vacuole in all his specimens, and his illustration of the frange is unambiguous. It seems likely, then, that his Nassula elegans was, in fact, a malnourished variety of Nassula ornata, as described by Edna McNally (Biol. Bull. October 1, 1926 vol. 51 no. 4 237-244 ).  Anterior, dorsal view.  Key to Schewiakoff's abbreviations:  ad.w -- Adoral ciliated zone c.p -- Cortical plasma g -- Gelatinous layer h -- Plasma of a homogeneous appearance. p -- Pellicle pi -- Pigmented spot