Rod like bacteria - Bacillus (plural bacilli).

In pairs – diplococci; In chains – streptococci. Still others look like cocci and are called coccobacilli (Fig. 2).

Spiral bacteria

Comma shaped – Vibrio (Vibrio); Helical, long and curved – Spirilla (Rhodospirillium); Helical and flexible – Sprirochetes (Treponema and Borrelia ) movement by axial filaments (Fig. 3).