Of the life-history of the Trichonymphidae,[136] all of which are parasitic in the alimentary canal of Insects, especially Termites or White Ants (Vol. V. p. 356), nothing is known. Some of them have a complete investment of motile flagella, like enormously long cilia, which in _Dinenympha_ appear to coalesce into four longitudinal undulating membranes. _Lophomonas_ inhabits the gut of the Cockroach and Mole-cricket. The Opalinidae have also a complete investment of cilia, which are short, and give the aspect of a Ciliate to the animal, which is common in the rectum of Amphibia, and dies when transferred to water. But despite the outward resemblance, the nuclei, of which there may be as many as 200, are all similar, and consequently this group cannot be placed among the Infusoria at all. _Opalina_ has no mouth nor contractile vacuole. It multiplies by dividing {124}irregularly and at intervals, resolving finally into 1-nucleate fragments, which encyst and pass into the water. When swallowed the cyst dissolves, its contents enlarge, and ultimately assume the adult form.[137] _Maupasia_ has a partial investment of cilia, a single long flagellum and mouth, a contractile vesicle, and a single simple nucleus. It seems to find an appropriate place near the two above groups, though it is free, and possesses a mouth. [Illustration: FIG. 42.—Longitudinal Fission of _Eutreptia viridis_ (Euglenaceae), showing chloroplasts, nucleus, and flagella arising from pharynx-tube. (After Steuer.)]