Bacteria may be classified according to the presence and absence of flagella as follow with examples-
(a) Monotrichous- Presence of one flagellum at one pole, eg. Vibrio.
(b) Lophotrichous- Presence of tuft of flagella at one pol, eg. Pseudomonas.
(c) Amphitrichous- Presence of tufts of flagella at both ends, eg. Spirillum.
(d) Peritrichous- Presence of many flagella surrounding the outer surface of the body, eg. Bacillus.
(e) Atrichous- Bacteria without flagella are called atrichous, eg. Diptheria bacillus.