Three new Troglodytella and a new Gorilloflasca ciliates (Entodiniomorphida) from mountain gorillas (Gorilla beringei beringei) in Rwanda.

Four new species, Troglodytella gracilis, T. virunga, T. dolium, and Gorilloflasca longior were described from the mountain gorillas in Rwanda. The three Troglodytella species share a retractable adoral ciliary zone, four non-retractable ciliary arches, two broad skeletal plates, a skeletal rod plate, numerous longitudinal cortical grooves, and four contractile vacuoles. The anterior ciliary arch is the longest of the four arches, extending transversely on the left body surface. T. gracilis and T. virunga are characterized by an elongated body, a tail flap, and a wedge-shaped macronucleus. T. virunga can be distinguished from T. gracilis by a trifurcate dorsal lobe, three right lobes, and two ventral spines. T. dolium has a barrel-shaped body and a rod-shaped or boomerang-shaped macronucleus. The buccal infraciliature of the three Troglodytella is composed of an adoral polybrachykinety, a perivestibular polybrachykinety, and paralabial kineties. G. longior has a long flask-shaped body, a vestibulum, a frontal lobe, a posterior cavity, an ellipsoidal or peanut-shaped macronucleus, a contractile vacuole, non-retractable adoral and vestibular ciliary zones in buccal area, a cavity ciliary zone, and two longitudinal dorsal ciliary zones. The infraciliature of G. longior is the same as that of G. africana.