Metacoronympha senta Kirby (Trichomonadida: Calonymphidae), an exclusive symbiont of Incisitermes (Kalotermitidae) divides by budding and unequal fission, so that large cells can divide to produce both large and small cells. In contrast to M. senta in Incisitermes snyderi from Florida, which has a unimodal population distribution and a maximum cell length of 90 [mu]m, M. senta in I. nr. incisus from Trinidad has a bimodal population distribution with cells as long as 210 [mu]m and with as many as 1000 nuclei, each associated with a mastigont organelle system (karyomastigont). A densely packed parabasal body (Golgi complex) is located on the cell membrane-side of each nucleus, which has a typical oval shape. Kirby's report of polygonal compartments, formed by contiguous nuclear membranes prove by electron microscopy to be microtubules of the axostyles arrayed as a polygon around each nucleus. Metacoronympha and other parabasalid symbionts (Coronympha, Trichonympha) of I. snyderi and I. nr. incisus are reported in this second paper ever written on this genus.