Genus: Elongate, ovoid; anterior apex often curves over the peristome; non contractile (Carey, 1992). In front of cytostome a two-layered undulating membrane on right edge; contractile vacuole and cytopyge terminal; rose-colored; many species (Kudo, 1966).
B. americanum
var. trinodatum
3 clips
μm
Vermont-Maine
USA, 1999