The theca is elongate, tubular, often slightly curved and irregu−
larly shaped. The apertural (proximal) end is usually
wider and more broadly rounded compared to the narrower apical (distal) end. The aperture is single, terminal, small and rounded. It may project slightly but
is sometimes retracted and invisible. The cytoplasm is white to yellowish, dense and fluffy with fine granules. It
fills the theca almost entirely, sometimes leaving small empty spaces at both ends.