1 — The A. describes two new species belonging to a new genus of flagellate Protozoa from the termite Kalotermes wagnerL Desneux and placed amongst the Oxymonadidae. 2 — They exhibit the general aspect of an oxymonad flagellate, although possesing a more complex rosteilum and a highly developed undulating axostyle, responsible for the movement of the organism. Flagella have been completely lost. 3 — During life-cycle, these flagellates present two forms viz. a young, swimming form and an adult form, attached to the gut wall of the termite. The fixed form is a flask-like organism, with a long rosteilum which possesses at its distal end an attachment disk. Ectoplasm is thick, chiefly at posterior end of the organism. Endoplasm full of brown spheres. The ex-tranuclear cinetic component is constituted by an undulating axostyle and two systems of chromophobe fibrils. The axostyle is a ribbon-like structure, vigorously undulating when living, intensily stained by iron haematein and eosin, and fixed posteriorly to the body wall through a special tube-like stru¬cture. The system of chromophobic fibrils is contituted by rostellar fibrils which connect the undulating portion of the axostyle to the tip of the rostellum. The other system referred to as independent chromoprobic fibrils takes origin at the distal end of the rostellum perhaps in granules there found, runs back¬ward through this organelle and reaches the body, where it suffers sub-di¬visions into thinner bundles. The nucleus presents the chromatin arranged in large, thick and irregular structures: there is no karyosome. The young form is much smaller and its undulating axostyle is relatively very large in relation to the size of the body. It is attached to the body wall at posterior end. During growth, this point moves foreward. Near the point where the tube-like structure is fastened to the surface of the body, a sheath can be observed, constituted by a great number of very fine hyaline strands. The endoplasm is deeply chromophile, but free from brown spheres, which makes their appearence after the fixation of the organism. The nucleus, at the early stages, exhibit very thin granules of chromatin with a uniform dispersion. One or more structures surrounded by a clear halo and simulating a karyosome can be seen at this stage; nevertheless they soon disappear. 4 — Before mitosis which is quite similar to that of Oxymonas grandis the nucleus migrates to the posterior end of the body, due to the degenera¬tion of the neuromotor organellae. The nuclear membrane persists during the whole process. A central spindle develops within the nucleus as a straight rod, reaches the nuclear membrane assuming a convex barrel shape, and suffering a torsion in opposite sense on each pole. At sites where centrioles must lie, a clear circular space can be seen, the spindle fibrils being attached to its periphery. The chromosomes are very minute structures, irregular in shape and in enormous number.