Genus: Euglenas in a close fitting lorica; a single long flagellum extends through small opening;
lorica with or without short collar; yellow to brown (How to know the protozoa, 1979).
Lorica often possesses numerous spines, composed of ferric hydroxide impregnated with brown
manganic compound (Kudo, 1966).
Species: Lorica smooth, broad ellipsoidal, both ends rounded, 18-24 μm long, 15-17 μm wide, collar curved, relatively long, about 4 μm high (An Illustrated Guide to Freshwater Zooplankton in Japan, 2000).
* Trachelomonas playfairi Deflandre: Lorica broad ellipsoid, smooth, rounded at both end; collar slightly curved; 19-23 μm long, 16-18.5 μm diam. (Illustrations of The Japanese Fresh-water Algae, 1977).
Trachelomonas horrida Palmer: 40 μm long; covered with short spines (How to know the protozoa, 1979).
Trachelomonas teres: 35 μm; lorica ovoid, with distinct collar (How to know the protozoa, 1979).