The mouth is anterior ventral and leads to a curved cytopharynx supported by a prominent palisade of rods or nematodesmata, forming a structure called a cyrtos or nasse, typical of this and a few other classes.

Among the former, and a few members of the latter, there is a series of small polykinetids running from below the mouth to the left side of the body and sometimes almost circling the cell, called a frange or synhymenium.

The body cilia are sparse, and often arise from dikinetids, with cirrus-like polykinetids occurring in the marine genus Discotricha.

As first defined by Eugene Small and Denis Lynn in 1981, the Nassophorea also included the peniculids and, in a separate subclass, the hypotrichs.

More recent schemes restore these to their earlier positions, leaving this group a relatively small collection of less well-known forms.