Non-motile Clostridia is

Clostridia are motile with peritrichous flagella. Exceptions are Clostridium perfringes and Clostridium tetani type IV which are non-motile. Motility is slow and has been described as 'stately'. C.perfringens and C.butyricum are capsulated, while others are not. Reference: Textbook of Microbiology; Anathanarayan and paniker's; 10th edition; Page no: 257