Genus: Ventral side with a hyaline border, reaching posterior end and bearing trichocysts; dorsal side with either similar trichocyst-border or with trichocyst-warts (Kudo, 1966). Species:

50 μm 100 μm 150 μm; x 400

L. rostratum Cohn, 1866: 100-180 μm long; well-defined neck region anterior; posteriorly rounded; ventral edge sinuous; a flattened band along both sides; two ovoid macronuclei; a single contractile vacuole posterior (Carey, 1992).