Nassophorea

The Nassophorea are a class of ciliates.[1] Members are free-living, usually in freshwater but also in marine and soil environments. 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. When present, extrusomes take the form of fibrous trichocysts. Cilia are usually monokinetids, but vary from order to order.

Nassophorea
Nassula sp.
Scientific classification
Kingdom:	Chromista
Subkingdom:	Harosa
Infrakingdom:	Halvaria
Superphylum:	Alveolata
Phylum:	Ciliophora
Subphylum:	Intramacronucleata
Class:	Nassophorea Small & Lynn 1981
Typical orders
Synhymeniida Nassulida Microthoracida

The Synhymeniida and Nassulida have mostly uniform cilia arising from monokinetids. 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. Other forms only have three oral membranelles, sometimes extending out of the oral cavity, with or without a paroral membrane. These are usually medium in size, sometimes larger, and cylinder shaped.

The Microthoracida typically have three or more oral membranelles, with at least a vestige of the paroral membrane occurring during cell division. The body cilia are sparse, and often arise from dikinetids, with cirrus-like polykinetids occurring in the marine genus Discotricha. These are usually small and ellipsoid or crescent shaped, with the right side of the body curved outward, and generally have a rigid pellicle.

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.